BREAST CANCER
What Is Cancer?
Cancer develops when cells in a part of the body begin to grow out of control. Although there are many kinds of cancer, they all start because of out-of-control growth of abnormal cells.
Normal body cells grow, divide, and die in an orderly fashion. During the early years of a person's life, normal cells divide more rapidly until the person becomes an adult. After that, cells in most parts of the body divide only to replace worn-out or dying cells and to repair injuries.
Because cancer cells continue to grow and divide, they are different from normal cells. Instead of dying, they outlive normal cells and continue to form new abnormal cells.
Cancer cells often travel to other parts of the body where they begin to grow and replace normal tissue. This process, called metastasis, occurs as the cancer cells get into the bloodstream or lymph vessels of our body. When cells from a cancer like breast cancer spread to another organ like the liver, the cancer is still called breast cancer, not liver cancer.
Cancer cells develop because of damage to DNA. This substance is in every cell and directs all its activities. Most of the time when DNA becomes damaged the body is able to repair it. In cancer cells, the damaged DNA is not repaired. People can inherit damaged DNA, which accounts for inherited cancers. Many times though, a person's DNA becomes damaged by exposure to something in the environment, like smoking.
Cancer usually forms as a tumor. Some cancers, like leukemia, do not form tumors. Instead, these cancer cells involve the blood and blood-forming organs, and circulate through other tissues where they grow.
Remember that not all tumors are cancerous. Benign (noncancerous) tumors do not spread to other parts of the body (metastasize) and, with very rare exceptions, are not life-threatening.
Different types of cancer can behave very differently. For example, lung cancer and breast cancer are very different diseases. They grow at different rates and respond to different treatments. That is why people with cancer need treatment that is aimed at their particular kind of cancer.
Cancer is the second leading cause of death in the United States. Half of all men and one-third of all women in the US will develop cancer during their lifetimes. Today, millions of people are living with cancer or have had cancer. The risk of developing most types of cancer can be reduced by changes in a person's lifestyle, for example, by quitting smoking and eating a better diet. The sooner a cancer is found and treatment begins, the better are the chances for living for many years.
What Is Breast Cancer?
Breast cancer is a malignant tumor that has developed from cells of the breast. The disease occurs mostly in women, but men can get it, too. The remainder of this document refers only to breast cancer in women. For information on breast cancer in men, see our separate document.
Normal Breast Structure
The female breast is made up mainly of lobules (milk-producing glands), ducts (milk passages that connect the lobules and the nipple), and stroma (fatty tissue and ligaments surrounding the ducts and lobules, blood vessels, and lymphatic vessels).
Lymphatic vessels are like veins, except that they carry lymph instead of blood. Lymph is a clear fluid that has tissue waste products and immune system cells. Cancer cells can enter lymph vessels. Most lymphatic vessels in the breast lead to axillary (underarm) lymph nodes.
Lymph nodes are small bean-shaped collections of immune system cells that are important in fighting infections. When breast cancer cells reach the axillary (underarm) lymph nodes, they may continue to grow, often causing the lymph nodes in that area to swell. If breast cancer cells have grown in the underarm lymph nodes, they are more likely to have spread to other organs of the body as well. This is why it is important to find out if breast cancer has spread to your axillary lymph nodes when you are choosing a treatment.
Benign Breast Lumps
Most breast lumps are benign, that is, not cancerous. Most lumps turn out to be fibrocystic changes. Cysts are fluid-filled sacs, and fibrosis refers to connective tissue or scar tissue formation. Fibrocystic changes can cause breast swelling and pain. Your breasts may feel nodular, or lumpy, and, sometimes, you may notice a clear or slightly cloudy nipple discharge. Benign breast tumors such as fibroadenomas or papillomas are abnormal growths, but they cannot spread outside of the breast to other organs. They are not life-threatening. For more information, see our document "Benign Breast Conditions."
Types of Breast Cancers
It is important for you to understand some of the key words used to describe different types of breast cancer, because breast cancers vary in their prognosis (the outlook for survival) and their treatment options.
Adenocarcinoma: Nearly all breast cancers start in glandular tissue of the breast and, therefore, are adenocarcinomas. The 2 main types of breast adenocarcinomas are ductal carcinomas and lobular carcinomas.
Ductal carcinoma in situ (DCIS): Ductal carcinoma in situ (also known as intraductal carcinoma) is the most common type of noninvasive breast cancer. Cancer cells are inside the ducts but they have not spread through the walls of the ducts into the fatty tissue of the breast. Nearly all women diagnosed at this early stage of breast cancer can be cured. A mammogram is the best way to find DCIS early. DCIS is sometimes subclassified by grade and type, to help predict the risk of cancer returning after treatment and to help select the most appropriate treatment. Grade refers to how aggressive cancer cells look under a microscope. There are several types of DCIS, but the most important distinction among them is whether or not tumor cell necrosis (areas of dead or degenerating cancer cells) is present. If necrosis is present, the tumor is considered more aggressive. The term comedocarcinoma is often used to describe a type of DCIS with necrosis.
Infiltrating (or invasive) ductal carcinoma (IDC): This is a cancer that starts in a milk passage, or duct, of the breast, and has broken through the wall of the duct and invaded the fatty tissue of the breast. At this point, it can metastasize, or spread, to other parts of the body through the lymphatic system and bloodstream. About 80% of invasive breast cancers are infiltrating ductal carcinomas.
Infiltrating (or invasive) lobular carcinoma (ILC): Infiltrating lobular carcinoma starts in the milk-producing glands. Similar to IDC, it also can spread (metastasize) to other parts of the body. About 10% to 15% of invasive breast cancers are ILCs. Invasive lobular carcinoma may be harder to detect by mammography than invasive ductal carcinoma.
Inflammatory breast cancer: This rare type of invasive breast cancer accounts for about 1% of all breast cancers. Inflammatory breast cancer makes the skin of the breast look red and feel warm, as if it was infected and inflamed. The skin has a thick, pitted appearance that doctors often describe as resembling an orange peel. Sometimes the skin develops ridges and small bumps that look like hives. Cancer cells blocking lymph vessels or channels in the skin over the breast cause these symptoms. Doctors now know that these changes are not caused by inflammation or infection, but the name given to this type of cancer long ago still persists.
In situ: This term is used for the early stage of cancer, when it is confined to the immediate area where it began. Specifically in breast cancer, in situ means that the cancer remains confined to ducts (ductal carcinoma in situ) or lobules (lobular carcinoma in situ). It has not invaded surrounding fatty tissues in the breast nor spread to other organs in the body.
Lobular carcinoma in situ (LCIS): Although it is not a true cancer, LCIS (also called lobular neoplasia) is sometimes classified as a type of noninvasive breast cancer. It begins in the milk-producing glands, but does not penetrate through the wall of the lobules.
Most breast cancer specialists think that LCIS, itself, does not become an invasive cancer, but women with this condition do have a higher risk of developing an invasive breast cancer in the same breast, or in the opposite breast. For this reason, it's important for women with LCIS to have a physical exam 2 or 3 times a year, as well as an annual mammogram.
Medullary carcinoma: This special type of infiltrating breast cancer has a relatively well-defined, distinct boundary between tumor tissue and normal tissue. It also has some other special features, including the large size of the cancer cells and the presence of immune system cells at the edges of the tumor. Medullary carcinoma accounts for about 5% of breast cancers. The outlook, or prognosis, for this kind of breast cancer is better than for other types of invasive breast cancer.
Mucinous carcinoma: This rare type of invasive breast cancer is formed by mucus-producing cancer cells. The prognosis for mucinous carcinoma is better than for the more common types of invasive breast cancer. Colloid carcinoma is another name for this type of breast cancer.
Paget's disease of the nipple: This type of breast cancer starts in the breast ducts and spreads to the skin of the nipple and then to the areola, the dark circle around the nipple. It is rare, accounting for only 1% of all cases of breast cancer. The skin of the nipple and areola often appears crusted, scaly, and red, with areas of bleeding or oozing. The woman may notice burning or itching. Paget's disease may be associated with in situ carcinoma, or with infiltrating breast carcinoma. If no lump can be felt in the breast tissue, and the biopsy shows DCIS but no invasive cancer, the prognosis is excellent.
Phyllodes tumor: This very rare type of breast tumor develops in the stroma (connective tissue) of the breast, in contrast to carcinomas, which develop in the ducts or lobules. Phyllodes (also spelled phylloides) tumors are usually benign but on rare occasions may be malignant (can metastasize). Benign phyllodes tumors are successfully treated by removing the mass and a narrow margin of normal breast tissue. A malignant phyllodes tumor is treated by removing it along with a wider margin of normal tissue, or by mastectomy. These cancers do not respond to hormonal therapy and are not so likely to respond to chemotherapy or radiation therapy. In the past, both benign and malignant phyllodes tumors were referred to as cystosarcoma phyllodes.
Tubular carcinoma: Tubular carcinomas are a special type of infiltrating breast carcinoma. They account for about 2% of all breast cancers, and have a better prognosis than infiltrating ductal or lobular carcinomas.
What Are the Key Statistics About Breast Cancer?
Breast cancer is the most common cancer among women, except for nonmelanoma skin cancers. It is estimated that in 2002 about 203,500 new cases of invasive breast cancer (Stages I to IV) will be diagnosed among women in the United States. Carcinoma in situ (CIS) accounts for about 54,300 new cases each year. CIS (Stage 0) is noninvasive and is the earliest form of breast cancer. Breast cancer also occurs in men. An estimated 1,500 cases will be diagnosed in men.
The breast cancer incidence rate, a measure of the number of new breast cancers per 100,000 women, increased by about 4.5% per year during the 1980s. During the 1990s, the incidence leveled off to 109.5 cases per 100,000 women.
In 2002, about 39,600 women and 400 men will die from breast cancer in the United States. Breast cancer is the second leading cause of cancer death in women, exceeded only by lung cancer. Death rates from breast cancer declined significantly during 1992 to 1996, with the largest decreases in younger women -- both white and black. These decreases are believed to be the result of earlier detection and improved treatment.
What Are the Risk Factors for Breast Cancer?
A risk factor is anything that increases your chance of getting a disease, such as cancer. Different cancers have different risk factors. For example, unprotected exposure to strong sunlight is a risk factor for skin cancer. Smoking is a risk factor for cancers of the lung, mouth, larynx, bladder, kidney, and several other organs.
But having a risk factor, or even several, does not necessarily mean that you will get the disease. Some women who have one or more breast cancer risk factors never develop the disease, while most women with breast cancer have no apparent risk factors. Even when a woman with breast cancer has a risk factor, there is no way to prove that it actually caused her cancer.
There are different kinds of risk factors. Some factors, like a person's age or race, can't be changed. Others are linked to cancer-causing factors in the environment. Still others are related to personal choices such as smoking, drinking, and diet. Some factors influence risk more than others, and your risk for breast cancer can change over time. Getting older, a new breast biopsy result, or a new diagnosis of breast cancer in your family could change your risk.
Risk Factors You Cannot Change
Gender: Simply being a woman is the main risk factor for developing breast cancer. Men can develop breast cancer, but this disease is about 100 times more common among women than men.
Aging: Your risk of developing breast cancer increases as you get older. About 77% of women with breast cancer are older than 50 when they are diagnosed. Only 0.3% of breast cancer cases occur in women younger than 30. Women in their 30s account for about 3.5% of cases.
Genetic risk factors: Recent studies have shown that about 10% of breast cancer cases are hereditary and that most of these result from mutations (changes) of the BRCA1 and BRCA2 genes. Normally, these genes help to prevent cancer by making proteins that keep cells from growing abnormally. However, if you have inherited a mutated gene from either parent, your chances of developing breast cancer increase. See the section "Do We Know What Causes Breast Cancer?" for more information about genes and DNA. About 50% to 60% of women with inherited BRCA1 or BRCA2 mutations will develop breast cancer by the age of 70. Women with these inherited mutations also have an increased risk for developing ovarian cancer.
Inherited mutations of the p53 tumor suppressor gene can also increase your risk of developing breast cancer, as well as leukemia, brain tumors, and/or sarcomas (cancer of bones or connective tissue). The Li-Fraumeni syndrome, named after the 2 researchers who described this inherited cancer syndrome, is a rare cause of breast cancer.
A genetic test analyzes your DNA from a blood sample to see if you have inherited a mutated BRCA1 or BRCA2. Testing the p53 gene is not part of the usual breast cancer genetic testing but may be done by specialized cancer genetics centers if the family history raises the possibility of Li-Fraumeni syndrome. If a mutated BRCA or p53 gene is found, more frequent exams will be scheduled to monitor for early signs of cancer.
Some women may choose to take the drug tamoxifen to reduce the likelihood of developing breast cancer. Some women at very high risk of developing breast cancer may choose to have a prophylactic mastectomy, that is, surgery to remove their breasts before cancer develops. See the section "Can Breast Cancer Be Prevented?" for more information on this option. BRCA mutations also increase ovarian cancer risk. Doctors may recommend removal of the ovaries after childbearing or after menopause, as there are currently no reliable methods of screening for ovarian cancer.
If you are considering genetic testing, we strongly recommend that you talk to a genetic counselor, nurse or doctor qualified to interpret and explain these test results, before testing. It is very important for people to understand and carefully weigh the benefits and risks of genetic testing before these tests are done. Testing is expensive, and is not covered by some health plans. There is concern that people with abnormal genetic test results will not be able to get life insurance, or that coverage may only be available at a much higher cost. For more information, see our position statement on genetic testing.
Family history of breast cancer: Women with first-degree relatives with breast cancer on either the mother's or father's side of the family have a higher breast cancer risk. Having 1 first-degree relative (mother, sister, or daughter) with breast cancer approximately doubles your risk, and having 2 first-degree relatives increases your risk 5-fold. Although the exact risk depends on several factors, women with a family history of breast cancer in male family members also have an increased risk of breast cancer.
Personal history of breast cancer: A woman with cancer in one breast has a 3- to 4-fold increased risk of developing a new cancer in the other breast or in another part of the same breast. This is different from a recurrence of the first cancer.
Race: White women are slightly more likely to develop breast cancer than are African-American women. But African- American women are more likely to die of this cancer because their cancers are often diagnosed at an advanced stage when they are harder to treat and cure. Asian, Hispanic, and American Indian women have a lower risk of developing breast cancer.
Previous breast biopsy: Women whose earlier breast biopsies detected proliferative breast disease without atypia or usual hyperplasia have a slightly higher risk of breast cancer (1.5 to 2 times greater than other women). Having a previous biopsy result of atypical hyperplasia increases a woman's breast cancer risk by 4 to 5 times. Having a biopsy specimen diagnosed as fibrocystic changes without proliferative breast disease does not affect breast cancer risk.
Previous breast irradiation: Women who as children or young women have had radiation therapy to the chest area as treatment for another cancer (such as Hodgkin's disease or non-Hodgkin's lymphoma) have a significantly increased risk for breast cancer.
Menstrual periods: Women who started menstruating at an early age (before age 12) or who went through menopause at a late age (after age 50) have a slightly higher risk of breast cancer.
Lifestyle-Related Factors and Breast Cancer Risk
Not having children: Women who have had no children or who had their first child after age 30 have a slightly higher breast cancer risk.
Oral contraceptive use: It is still not clear what part oral contraceptives (birth control pills) might play in breast cancer risk. Studies have found that women now using oral contraceptives have a slightly greater risk of breast cancer than women not using them. Women who stopped using oral contraceptives more than 10 years ago do not appear to have any increased breast cancer risk. When considering using oral contraceptives, women should discuss their other risk factors for breast cancer with their health care team.
Hormone replacement therapy: Most studies suggest that long-term use (5 years or more) of hormone replacement therapy (HRT) after menopause may slightly increase your risk of breast cancer. If you still have your uterus (womb), doctors generally prescribe estrogen and progesterone. Estrogen is prescribed to prevent menopausal symptoms and osteoporosis. It, however, can increase the risk of developing cancer of the uterus. Progesterone helps prevent cancer of the uterus.
If you no longer have your uterus, then only estrogen is prescribed. Recently, doctors from the National Cancer Institute found that the increased risk of breast cancer related to combined HRT is mostly due to the progesterone. However, more studies are necessary to confirm this conclusion. Estrogen alone does not increase the risk as much.
The risk of HRT applies only to current and recent users, and a woman's breast cancer risk appears to return to that of the general population within 5 years of stopping HRT. HRT reduces the risk of bone fractures. The decision to use hormone replacement therapy after menopause should be made by the woman and her doctor after weighing the possible risks and benefits. Factors to consider include your other risk factors for breast cancer, osteoporosis (thinning and weakening of bones), and the severity of menopausal symptoms.
Not breast feeding: Some studies suggest that breast feeding may slightly lower breast cancer risk, especially if continued for 1½ to 2 years. Other studies found no impact on breast cancer risk.
Alcohol: Drinking alcoholic beverages clearly increases the risk of developing breast cancer. Compared with nondrinkers, women who consume 1 alcoholic drink a day have a very small increase in risk, and those who have 2 to 5 drinks daily, have about 1½ times the risk of women who drink no alcohol. Alcohol is also known to increase the risk of developing cancers of the mouth, throat, and esophagus. We recommend limiting your consumption of alcohol, if you drink at all.
Obesity and high-fat diets: Obesity (being overweight) is associated with an increased risk of developing breast cancer, especially for women after menopause (which usually occurs at age 50). Although your ovaries produce most of your estrogen, fat tissue can change some other hormones into estrogen. Having more fat tissue can increase your estrogen levels, and increase your likelihood of developing breast cancer.
The connection between weight and breast cancer risk is complex, however. For example, risk appears to be increased for women who gained weight as an adult but is not increased among those who have been overweight since childhood. Also, excess fat in the waist area affects risk more than the same amount of fat in the hips and thighs. Researchers believe that fat cells in various parts of the body have subtle differences in their metabolism that may explain this observation.
Studies of fat in the diet and breast cancer risk have often given conflicting results. Most studies found that breast cancer is less common in countries where the typical diet is low in total fat, low in polyunsaturated fat, and low in saturated fat.
On the other hand, many studies of women in the United States have not found breast cancer risk to be related to dietary fat intake. Researchers are still not sure how to explain this apparent disagreement. Many scientists note that studies comparing diet and breast cancer risk in different countries are complicated by other differences (such as activity level, intake of other nutrients, genetic factors) that might also alter breast cancer risk.
More research is needed to better understand the effect of the types of fat eaten and body weight on breast cancer risk. But, these factors have been shown to influence the risk of developing several other types of cancer, and intake of certain types of fat is clearly related to heart disease risk. We recommend you maintain a healthy weight and limit your intake of red meats, especially those high in fat or processed.
Physical inactivity: Exercise and cancer is a relatively new area of research. Recent studies show that strenuous exercise in your youth might provide life-long protection against breast cancer, and that even moderate physical activity as an adult can lower breast cancer risk. Additional research is being done to confirm these findings.
Environmental pollution: A great deal of research has been reported and more is being done to understand environmental influences on breast cancer risk. The goal is to determine their possible relationships to breast cancer.
Currently, research does not show a clear link between breast cancer risk and exposure to environmental pollutants, such as the pesticide DDE (chemically related to DDT), and PCBs (polychlorinated biphenyls). Although a few studies have suggested certain pollutants increase breast cancer risk, most experts believe that if such a connection exists, it accounts for a very small portion of breast cancer cases.
Factors with Uncertain, Controversial, or Unproven Effect on Breast Cancer Risk
Antiperspirants: Internet e-mail rumors have suggested that chemicals in underarm antiperspirants are absorbed through the skin, interfere with lymph circulation, and cause toxins to build up in the breast and eventually lead to breast cancer. There is no experimental or epidemiologic evidence to support this rumor. Chemicals in products such as antiperspirants are tested thoroughly to ensure their safety. The claims about toxin accumulation are not supported by the scientific basis of carcinogenesis (cancer formation).
Underwire bras: Internet e-mail rumors and at least one book have suggested that bras cause breast cancer by obstructing lymph flow. There is no scientific or clinical basis for that claim.
Smoking: Most studies on smoking and breast cancer risk have not found any association. Nonetheless, studies have shown that smoking negatively affects overall health and increases the risk for many other cancers, as well as heart disease and stroke.
Induced abortion: A recent, large study from Denmark has provided very strong data that induced abortions have no overall effect on the risk of breast cancer. Also, there is no evidence of a direct relationship between breast cancer and spontaneous abortion (miscarriage) in most of the studies that have been published.
Breast implants: Silicone breast implants can cause scar tissue to form in the breast, but several studies have found that they do not increase breast cancer risk. Implants do make it harder to see breast tissue on standard mammograms, but additional x-ray pictures called implant displacement views can be used to completely examine the breast tissue.
Do We Know What Causes Breast Cancer?
Although we know some of the risk factors that increase your chance of developing breast cancer, we do not yet know what causes most breast cancers or exactly how some of these risk factors cause cells to become cancerous. Scientists are making great progress in understanding how certain changes in DNA can cause normal breast cells to become cancerous. DNA is the chemical that carries the instructions for nearly everything our cells do. We usually resemble our parents because they are the source of our DNA. However, DNA affects more than our outward appearance.
Some genes (parts of DNA) contain instructions for controlling when our cells grow, divide, and die. Certain genes that promote cell division are called oncogenes. Others that slow down cell division, or cause cells to die at the right time, are called tumor suppressor genes. It is known that cancers can be caused by DNA mutations (changes) that "turn on" oncogenes or "turn off" tumor suppressor genes. Certain inherited DNA changes can cause a high risk for developing cancer in people who carry these changes and are responsible for the cancers that run in some families.
Most DNA mutations related to breast cancer, however, occur in single breast cells during a woman's life rather than having been inherited. Acquired mutations of oncogenes and/or tumor suppressor genes may result from radiation or cancer-causing chemicals. So far, however, studies have not been able to identify any chemical in the environment or in our diets that is likely to cause these mutations, or a subsequent breast cancer. The cause of most acquired mutations remains unknown.
Women have already begun to benefit in several ways from recent advances in understanding the genetic basis of breast cancer. The section "What Are The Risk Factors For Breast Cancer?" explains how genetic testing can identify some women who have inherited abnormal BRCA1, BRCA2, or p53 tumor suppressor genes. These women can then take steps to reduce their risk of developing breast cancers, and to monitor changes in their breasts carefully to find cancer at an earlier, more treatable stage.
Most breast cancers have several gene mutations. The mutations are not inherited and cannot be passed on, but instead develop during a woman's lifetime. It may be useful to identify acquired changes of the HER2 oncogene in some women with breast cancer to help them make decisions about the best treatment.
Tests to identify other acquired changes in oncogenes or tumor suppressor genes (such as p53) may help doctors more accurately predict the survival outcome of some women with breast cancer. But, with the exception of the HER2 oncogene, these tests have not yet been shown to be useful in making decisions about treatment and are used only for research purposes.
A monoclonal antibody therapy called trastuzumab (Herceptin) has been developed that specifically interrupts the growth-promoting action of the HER2 oncogene. This breast cancer treatment is discussed under "How is Breast Cancer Treated?"
Can Breast Cancer Be Prevented?
Currently, there is no way to prevent breast cancer. For now, the best plan if you are a woman at average risk for breast cancer is to reduce your risk factors whenever possible. (See the section "What Are The Risk Factors For Breast Cancer?")
Following the American Cancer Society's guidelines for early detection as outlined in "Can Breast Cancer be Found Early?" will not prevent breast cancer, but can help find cancers when the likelihood of successful treatment is greatest.
Breast Cancer Risk Reduction with Tamoxifen or Raloxifene
Tamoxifen has been used for many years to reduce the risk of recurrence in localized breast cancer and as a treatment for advanced breast cancer. (See "How is Breast Cancer Treated?") Results from the Breast Cancer Prevention Trial (BCPT) have shown that women at high risk for breast cancer are less likely to develop the disease if they take the antiestrogen drug, tamoxifen. After taking tamoxifen an average of 4 years, these women had 45% fewer breast cancers than women with the same risk factors who did not take tamoxifen. (For additional information, see our document, "Tamoxifen and Raloxifene: Questions and Answers.")
Like tamoxifen, raloxifene also blocks the effect of estrogen on breast tissue. In a study to evaluate raloxifene as prevention for osteoporosis, the researchers also noticed that it too, seemed to lower the risk of breast cancer. A comparison of the effectiveness of the 2 drugs, called the Study of Tamoxifen and Raloxifene or the STAR trial, is currently underway. For now, raloxifene has not yet been approved for use in reducing breast cancer risk.
Prophylactic (preventive) mastectomy for women with very high breast cancer risk: Occasionally, a woman who is at very high risk for breast cancer will choose to have a prophylactic mastectomy. The purpose of the surgery is to reduce the risk by removing both breasts before breast cancer is diagnosed. The reasons for considering this type of surgery may include one or more of the following risk factors:
There is no way to know ahead of time how this surgery will affect a particular woman. Some women with BRCA mutations will develop a fatal breast cancer early in life, and a prophylactic mastectomy before the cancer occurs might add many years to their life expectancy. Some women with BRCA mutations never develop breast cancer, and these women would not benefit from the surgery.
Still other women might develop breast cancer that can be found by mammography or breast examination, and be treated and cured; these women's life expectancies would also not be affected by the operation. It is important to realize that while this operation removes nearly all of the breast tissue, a small amount remains. So, although this operation markedly reduces the risk of breast cancer, a cancer can still develop in the breast tissue remaining after surgery.
Second opinions are strongly recommended before any woman makes the decision to have this surgery. The American Cancer Society Board of Directors has stated "only very strong clinical and/or pathologic indications warrant doing this type of "preventive operation." Nonetheless, after careful consideration, this might be the right choice for some women.
Can Breast Cancer Be Found Early?
Following the American Cancer Society's guidelines for the early detection of breast cancer improves the chances that breast cancer can be diagnosed at an early stage and treated successfully.
Mammography
A mammogram is an x-ray of the breast. Diagnostic mammography is used to find breast disease in women who have symptoms such as the changes listed above. Screening mammography is used to look for breast disease in women who are asymptomatic, that is, they appear to have no breast problems.
Although breast x-rays have been performed for more than 70 years, modern mammography has only existed since 1969. That was the first year x-ray units specifically for breast imaging were available. Modern mammography equipment designed specifically for breast x-rays, uses very low levels of radiation, usually a dose of about 0.1 to 0.2 rads per picture.
Strict guidelines are in place to ensure that mammography equipment is safe and uses the lowest dose of radiation possible. Many people are concerned about the exposure to x-rays, but the level of radiation in modern mammography does not significantly increase the risk for breast cancer.
To put dose into perspective, if a woman with breast cancer is treated with radiation, she will receive several thousands rads. If she had yearly mammograms beginning at age 40 and continuing until she was 90, she will have received 20-40 rads. As another example, one mammogram exposes a woman to roughly the same amount of radiation as flying from New York to California on a commercial jet.
For a mammogram, the breast is pressed between 2 plates to flatten and spread the tissue. Although this may be temporarily uncomfortable, it is necessary to produce a good, "readable" mammogram. The compression only lasts a few seconds, and the entire procedure for screening mammography takes about 20 minutes. This procedure produces a black and white image of the breast tissue on a large sheet of film that is read, or interpreted, by a radiologist. The doctor reading the films will look for several types of changes.
Calcifications, or microcalcifications, are tiny mineral deposits within the breast tissue that appear as small white spots on the film. They may occur singly or in clusters. They are a sign of changes within the breast and can either be carefully watched by additional, periodic mammograms, or can be examined by biopsy (removal of a small amount of breast tissue). They may be caused by benign breast conditions, or, less often, by breast cancer. A mass, which may occur with or without calcifications, is another important change that can be seen on a mammogram, Masses can be many things, including cysts and fibroadenomas, but they may be cancer and usually should be biopsied if they are not fluid-filled cysts.
A cyst, which is a benign collection of fluid in the breast, cannot be diagnosed by physical exam alone, nor can it be diagnosed by mammography alone. Either breast ultrasound, or removal of the fluid with a needle (aspiration), is used to confirm that a mass is a cyst. If a mass is not a cyst, then it may be looked at further.
A mammogram cannot prove that an abnormal area is cancer. To confirm whether cancer is present, a small amount of tissue must be removed and examined under a microscope. This procedure is called a biopsy. For more information, see our document "Mammography and Other Breast Imaging Procedures."
Things to Expect When You Get a Mammogram
Financial assistance for breast cancer testing for low-income women: Breast cancer testing is now more available to medically underserved women through the National Breast and Cervical Cancer Early Detection Program (NBCCEDP). This program provides breast and cervical cancer early detection testing to women without health insurance for free or at very little cost. The NBCCEDP attempts to reach as many women in medically underserved communities as possible, including older women, women without health insurance and women who are members of racial and ethnic minorities. Although the program is administered within each state, the Centers for Disease Control and Prevention (CDC) provide matching funds and support to each state program.
Offered mainly through non-profit organizations and local health clinics, this program makes testing available for breast and cervical cancer in medically underserved women. Each state's Department of Health will have information on how to contact the nearest program.
In 2000, the Breast and Cervical Cancer Treatment Act was signed into law. This act enhances the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) by providing funds to pay for treatment associated with breast and cervical cancer in medically underserved populations. Implementation of this new option will help women focus their energies on fighting their disease, instead of worrying about how to pay for treatment. As with the Early Detection Program, individual states must adopt the program in order to receive the matching federal funds.
To learn more about this program, please contact the CDC at 1-888-842-6355 or on the Internet at www.cdc.gov/cancer.
Clinical Breast Examination
A clinical breast examination (CBE) is an examination of your breasts by a health care professional, such as a doctor, nurse practitioner, nurse, or doctor's assistant. For this examination, you undress from the waist up. The health care professional will first look at your breasts for changes in size or shape. Then, using the pads of the fingers, the examiner will gently palpate (feel) your breasts. Special attention will be given to the shape and texture of the breasts, location of any lumps, and whether such lumps are attached to the skin or to deeper tissues. The area under both arms will also be examined. During the CBE is a good time for the health care professional to teach breast self-examination to the woman who does not already know how to examine her breasts. Ask your doctor or nurse to teach you and watch your technique.
Breast Self-Examination
If you regularly examine your own breasts, you will probably notice any changes. The best time for breast self examination (BSE) is about a week after your period ends, when your breasts are not tender or swollen. If you are not having regular periods, do BSE on the same day every month.
How Is Breast Cancer Diagnosed?
If screening tests or your signs and symptoms suggest breast cancer, your doctor will use one or more methods to determine if the disease is present and to evaluate the stage of the cancer.
Signs and Symptoms
Although widespread use of screening mammography has increased the number of breast cancers found before they cause any symptoms, some breast cancers are not found by mammography, either because the test was not done or because even under ideal conditions mammography cannot find every breast cancer.
The most common sign of breast cancer is a new lump or mass. A painless, hard mass that has irregular edges is more likely to be cancerous, but some rare cancers are tender, soft, and rounded. For this reason, it is important that a health care professional who is experienced in diagnosing breast diseases check any new breast mass or lump.
Other signs of breast cancer include a generalized swelling of part of a breast (even if no distinct lump is felt), skin irritation or dimpling, nipple pain or retraction (turning inward), redness or scaliness of the nipple or breast skin, or a discharge other than breast milk. Sometimes a breast cancer can spread to underarm lymph nodes even before the original tumor in the breast tissue is large enough to be felt.
Medical History and Physical Examination
The first step in evaluation of a woman with suspected breast cancer is getting a complete medical history and physical examination. Your doctor will ask questions about your symptoms, any other health problems, and risk factors for benign breast conditions and breast cancer (such as whether or not any of your relatives had benign breast conditions, breast cancer, or other cancers). Your breast will be thoroughly examined to locate any lump or suspicious area and feel its texture, size, and relationship to the skin and chest muscles. Any changes in the nipples or the skin of your breast will be noted. The lymph nodes under the armpit and above the collarbones may be palpated (felt), because enlargement or firmness of these lymph nodes might indicate spread of breast cancer. In addition to the medical history and physical exam, imaging tests and biopsies may be done.
Imaging Tests to Diagnose Breast Disease
Diagnostic mammography: Diagnostic mammography is an x-ray examination of the breast of a woman who has a breast problem (for example, a breast mass, nipple discharge, etc.) or who has an abnormality that was found on a screening mammogram. In some cases, special images known as cone views with magnification are used to make a small area of altered breast tissue easier to evaluate.
A diagnostic mammography work-up may show that a lesion (area of abnormal tissue) has a high likelihood of being benign (not cancer). In these cases, it is common to ask the woman to come back sooner than usual for a recheck, usually in 4 to 6 months. On the other hand, a diagnostic mammogram may show that the abnormality is not worrisome at all, and the woman can then return to having routine yearly mammograms. Finally, the diagnostic work-up may suggest that a biopsy is needed to tell if the lesion is cancer.
Breast ultrasound: Ultrasound, also known as sonography, uses high-frequency sound waves to outline a part of the body. High-frequency sound waves are transmitted into the area of the body being studied and echoed back. A computer picks up the sound wave echoes and changes them into an image that is displayed on a computer screen. You are not exposed to radiation during this test. Breast ultrasound is sometimes used to evaluate breast abnormalities that are found during mammography or a physical exam. Ultrasound is useful for detecting some breast masses, and is the easiest way to tell if a cyst is present without placing a needle into it to draw out fluid.
Ductogram: This test, also called a galactogram, is sometimes helpful in determining the cause of a nipple discharge. In this test a fine plastic tube is placed into the opening of the duct at the nipple. A small amount of contrast medium is injected, which outlines the shape of the duct on an x-ray image and will show if there is a mass inside the duct.
Nipple Discharge Examination
If you have a nipple discharge, some of the fluid may be collected and examined under a microscope to see if any cancer cells are in it. Most nipple discharges or secretions are not cancer. In general, if the secretion appears clear or milky, cancer is very unlikely. If the discharge is red or red-brown, suggesting that it contains blood, it might possibly be caused by cancer, although an infection or benign tumor are more likely causes. Even when no cancer cells are found in a nipple discharge, it is not possible to say for certain that a breast cancer is not present. If a patient has a suspicious mass, a biopsy is necessary, even if the nipple smear does not contain cancer cells.
Ductal Lavage
Used only for women who are at high risk for breast cancer, ductal lavage is a procedure that collects cells from inside the milk ductal system, where most breast cancers begin. If any abnormal (or "atypical") cells are found, they indicate a significantly higher risk of breast cancer, but they are not necessarily considered cancerous or pre-cancerous.
Ductal lavage can be done in a doctor's office or an outpatient facility. It has 3 steps:
The collection vial is then sent to a laboratory where the cells are examined.
When used with mammography and breast examination, the information gathered from ductal lavage may help physicians and women at high risk for breast cancer weigh the potential risks and benefits of various options such as closer surveillance and using drug therapy to reduce breast cancer risk.
Today, ductal lavage is not considered appropriate for women who aren't at high risk for breast cancer. Although ductal lavage has detected a few early-stage malignancies, research is underway to determine its false-positive and false-negative rates. It is too early to tell whether ductal lavage will be reliable as a cancer detection method.
Devices used in ductal lavage have been cleared by the FDA.
Biopsy
A biopsy is done when mammography, ultrasound, or the physical examination finds something unusual. A biopsy is the only way to tell if cancer is really present. All biopsy procedures remove a tissue sample for examination under a microscope. There are several types of biopsies, such as fine needle aspiration biopsy, core biopsy, and surgical biopsy. Each type of biopsy has distinct advantages and disadvantages.
The choice of which to use will depend on your specific situation. Some of the factors your doctor will consider include how suspicious the lesion appears, how large it is, where in the breast it is located, how many lesions are present, other medical problems you may have, and your personal preferences. You might want to discuss the advantages and disadvantages of different biopsy types with your doctor.
Fine needle aspiration biopsy (FNAB): A thinner needle is used for FNAB than the ones used for blood tests. The needle can be guided into the area of the breast abnormality while the doctor is palpating (feeling) the lump. If the lump can't be felt easily, your doctor might use ultrasound or a method called stereotactic needle biopsy to guide the needle. Ultrasound lets the doctor watch the needle on a screen as it moves toward and into the mass. For stereotactic needle biopsy, computers map the exact location of the mass using mammograms taken from two angles. Then a computer guides the needle to the right spot.
Once the needle is in place, fluid is drawn out. If the fluid is clear, the lump is probably a benign cyst. Bloody or cloudy fluid can mean either a benign cyst or very rarely, a cancer. If the lump is solid, small tissue fragments are drawn out. Microscopic examination of FNAB samples can tell whether most breast abnormalities are benign or cancerous.
If the FNAB does not provide a clear diagnosis, it is important to have another type of biopsy. If the FNAB results are interpreted as benign but the lump feels suspicious to the examining doctor or appears suspicious on mammography, the possibility of a false-negative FNAB result should be considered.
Depending on your individual situation and specific test results, your options would include having another FNAB, having another type of biopsy, or close clinical follow-up (repeating physical examinations and/or mammography sooner than indicated by routine screening guidelines).
Core needle biopsy: A core biopsy can sample abnormalities felt by the doctor as well as smaller ones pinpointed by ultrasound or stereotactic methods. Depending on whether or not the abnormality can be felt, about 3 to 5 cores are usually removed.
The needle used in core biopsies is larger than that used in FNAB. It removes a small cylinder of tissue (about 1/16 to 1/8 inch in diameter and ½ inch long) from a breast abnormality. The biopsy is done with local anesthesia in the doctor's office.
Surgical biopsy: Sometimes, surgery is needed to remove all or part of the lump for microscopic examination. An excisional biopsy removes an entire lesion (breast abnormality such as a mass or area containing calcifications) as well as a surrounding margin of normal-appearing breast tissue. In rare circumstances, this type of biopsy can be done in the doctor's office, but it is more commonly done in the hospital's outpatient department under a local anesthesia (you are awake during the procedure but your breast is numb). Intravenous sedation is often given to make you less aware of the procedure.
The surgeon may use a procedure called a wire localization during an excisional breast biopsy if there is a small lump that is hard to locate by touch or if an area looks suspicious on the x-ray (due to calcifications, for example) but cannot be felt. After the area is numbed with local anesthetic, a thin hollow needle is placed into the breast and x-ray views are used to guide the needle to the suspicious area. A thin wire is inserted through the center of the needle. A small hook at the end of the wire keeps it in place. The hollow needle is then removed, and the surgeon uses the wire to locate the abnormal area to be removed.
If a benign condition is diagnosed, no further treatment is needed. If the diagnosis is cancer, there is time for you to learn about the disease and to discuss all treatment options with your cancer care team, friends, and family. The short delay until treatment does no harm.
The excisional biopsy is considered the first step of a 2-step procedure. The second step is to complete local treatment of the breast cancer. As discussed under "How Is Breast Cancer Treated?" this may involve radiation therapy and/or additional surgery. A diagnosis made by needle biopsy also counts as the first step of a 2-step procedure. Today, most health care professionals prefer this 2-step procedure.
Before the 1980s, the only choice you had was a one-step procedure. With this approach, you would be given general anesthesia and would be asleep during the entire process. A biopsy was done and immediately examined in the pathology laboratory under a microscope. During the one-step procedure, if cancer cells were present, the surgeon immediately went ahead with treatment such as mastectomy, which you would have previously approved. You would not know until you woke up whether the lump was cancerous and whether your breast had been removed. This approach is rarely used now.
Other stereotactic biopsy methods: One potential disadvantage of fine needle and core biopsy methods for biopsy of abnormalities found by mammography (such as microcalcifications) is that they remove only a small sample of tissue from the abnormal area. If the biopsy finds cancer, it can be assumed to be accurate. But, if no cancer is found, it could also be because the needle missed the target. Until recently, an excisional biopsy with wire localization was the only way to remove all or most of a non-palpable (seen on mammography but cannot be felt) area of abnormal tissue containing microcalcifications.
Two new devices have been invented that can be guided by stereotactic methods and can remove more tissue than a core biopsy. The Mammotome, also known as vacuum-assisted biopsy, suctions tissue into a cylinder inserted into the breast tissue. A rotating knife then cuts the tissue samples from the breast. This method usually removes about twice as much tissue as core biopsies. The ABBI method (short for Advanced Breast Biopsy Instrument) uses a rotating circular knife to remove a large cylinder of tissue.
The US Food and Drug Administration (FDA) recently approved both the Mammotome and ABBI instruments to diagnose breast abnormalities. But, breast specialists still disagree about when each of these instruments should be used for diagnosis of non-palpable abnormalities, and whether some should be used at all. There is even more disagreement about whether the ABBI should be used in some situations to replace an excisional biopsy with wire localization as a lumpectomy procedure.
Laboratory Tests to Determine Breast Cancer Prognosis
Types of breast cancer: The tissue removed during the biopsy is examined in the lab to see whether the cancer is in situ (not invasive) or invasive. The biopsy is also used to determine the cancer's type. These types of breast cancer are defined in the section "What Is Breast Cancer?" The most common types, invasive ductal and invasive lobular cancer, are treated in the same way. In some cases, breast cancer types that tend to have a more favorable prognosis (medullary, tubular, and mucinous cancers) are treated differently. For example, hormonal therapy or chemotherapy may be recommended for small stage I cancers with unfavorable microscopic features but not for small cancers of the types associated with a more favorable prognosis.
Grades of breast cancer: A pathologist looks at the tissue sample under a microscope and then assigns a grade to it. The grade helps predict the patient's prognosis because cancers that closely resemble normal breast tissue tend to grow and spread more slowly. In general, a lower grade number indicates a slower-growing cancer while a higher number indicates a faster-growing cancer.
Histologic tumor grade (sometimes called its Bloom-Richardson grade, Scarff- Bloom-Richardson grade, or Elston-Ellis grade) is based on the arrangement of the cells in relation to each other, as well as features of individual cells. This system of grading is used for invasive cancers but not for in situ cancers.
Ductal carcinoma in situ (DCIS) is sometimes given a nuclear grade, which describes how abnormal the cancer cells appear. The presence or absence of necrosis (areas of degenerating cancer cells) is also noted. Some researchers have suggested combining information about the nuclear grade and necrosis with information about the surgical margin (how close the cancer is to the edge of the lumpectomy specimen) and the size (amount of breast tissue affected by DCIS). The researchers suggest assigning a score to each of these features and adding them together. This sum is called the Van Nuys Prognostic Index. In situ cancers with high nuclear grade, necrosis, cancer at or near the edge of the lumpectomy sample, and large areas of DCIS are more likely to come back after lumpectomy.
Estrogen and progesterone receptors: Receptors are parts of cells that can detect certain substances such as hormones that circulate in the blood. Normal breast cells and some breast cancer cells have receptors that detect estrogen and progesterone. These 2 hormones play an important role in the development, growth, prognosis, and treatment of breast cancer.
An important step in evaluating a breast cancer is to test a portion of the cancer removed during the biopsy or initial surgical treatment for the presence of these receptors. Breast cancers that contain estrogen and progesterone receptors are often referred to as ER-positive and PR-positive tumors. Women with these cancers tend to have a better prognosis and are much more likely to respond to hormonal therapy than women with cancers without these receptors (see "How Is Breast Cancer Treated?").
Tests of ploidy and cell proliferation rate: The ploidy of cancer cells refers to the amount of DNA they contain. If there's a normal amount of DNA, the cells are said to be diploid. If the amount is abnormal, then the cells are described as aneuploid. Some studies have found that aneuploid breast cancers tend to be more aggressive. There are 2 tests commonly used to determine whether breast cancer cells are diploid or aneuploid.
Flow cytometry can also measure the S-phase fraction, which is the percentage of cells in a sample that are replicating (copying) their DNA. DNA replication means that the cell is getting ready to divide into 2 new cells. The rate of cancer cell division can also be estimated by a Ki-67 test, which identifies cells in the S-phase as well as cells getting ready to replicate DNA, cells that have just completed DNA replication, and cells in the process of dividing.
The Ki-67 test uses a thin slice of the biopsy specimen, which is treated with special antibodies and other chemicals that make certain cells change color. The percentage of cells that change color in this test is called the Ki-67 fraction or Ki-67 labeling index. A high S-phase fraction or Ki-67 labeling index means that the cancer cells are dividing more rapidly, and tends to be associated with more aggressive cancers.
HER2/neu testing: About 1/3 of breast cancers have too much of a growth-promoting protein called HER2/neu and too many copies of the gene that instructs the cells to produce that protein. In other cases, a normal number of HER2/neu genes are present, but they are too active in instructing the cells to produce HER2/neu protein. These cancers tend to grow and spread more aggressively than other breast cancers. They can be treated with a drug called Herceptin® that prevents the HER2/neu protein from stimulating breast cancer cell growth (see section "How Is Breast Cancer Treated?" for information about this drug). Studies also suggest that chemotherapy combinations containing anthracycline drugs (such as doxorubicin or epirubicin) treat breast cancers with too much HER2/neu more effectively than combinations that do not include these drugs. HER2/neu testing is done on thin slices of the biopsy sample that are treated with special antibodies that identify the HER2/neu protein or with pieces of DNA that identify the HER2/neu gene. The test that uses antibodies to detect HER2/neu protein is called immunohistochemistry. The DNA test for extra copies of the HER2/neu gene is called fluorescent in situ hybridization (usually called FISH for short).
Other tests to predict breast cancer prognosis: Many new prognostic factors, such as changes of the p53 tumor suppressor gene, the epidermal growth factor receptor, and microvessel density (number of small blood vessels that supply oxygen and nutrition to the cancer), are currently being studied. See "What's New In Breast Cancer Research and Treatment?"
How Is Breast Cancer Staged?
Staging is the process of finding out how widespread a cancer is. The stage of a cancer is the most important factor in considering treatment options. A staging system is a standardized way for the cancer care team to summarize information about how far a cancer has spread.
Depending on the results of your physical exam and biopsy, your doctor may want you to have certain imaging tests such as a chest x-ray, mammograms of both breasts, bone scans, and computed tomography (CT) or magnetic resonance imaging (MRI) scans. Blood tests to evaluate your overall health and help detect whether the cancer has spread to certain organs may also be done.
The American Joint Committee on Cancer (AJCC) TNM System
The most common system used to describe the stages of cancers is the American Joint Committee on Cancer (AJCC) TNM system. T stands for tumor (its size and how far it has spread within the breast and to nearby organs). N stands for spread to lymph nodes (bean-sized collections of immune system cells that help fight infections and cancers). M is for metastasis (spread to distant organs). Using the TNM staging system, information about the tumor, lymph nodes, and metastasis is combined to assign a stage. This process is called stage grouping. The stage is described in Roman numerals from I to IV.
The letter T followed by a number from 0 to 4 describes the tumor's size and spread to the skin or chest wall under the breast. Higher T numbers indicate a larger tumor and/or wider spread to tissues near the breast.
The letter N followed by a number from 0 to 3 indicates whether the cancer has spread to lymph nodes near the breast and, if so, whether the affected nodes are fixed (stuck) to other structures under the arm.
The letter M followed by a 0 or 1 means the cancer has spread to distant organs (for example, the lungs or bones) or to lymph nodes that are not next to the breast, such as those above the collarbone.
Once the T, N, and M categories have been determined, this information is combined in a process called stage grouping to determine your disease stage. This is expressed as stage 0 and in Roman numerals from stage I (the least advanced stage) to stage IV (the most advanced stage).
Summary of Breast Cancer Stages
Stage 0: Ductal carcinoma in situ (DCIS) is the earliest form of breast cancer. In DCIS, cancer cells are located within a duct and have not invaded the surrounding fatty breast tissue.
Lobular carcinoma in situ (LCIS), also called lobular neoplasia, is sometimes classified as stage 0 breast cancer, but is believed by most oncologists not to be a true breast cancer. In lobular carcinoma in situ, abnormal cells grow within the lobules or milk-producing glands, but they do not penetrate through the wall of these lobules.
Most breast cancer specialists think that LCIS itself does not usually become an invasive cancer, but that women with this condition are at increased risk of later developing an invasive breast cancer elsewhere in the same breast or in the opposite breast. This later cancer may be either invasive ductal or invasive lobular.
Stage I: The tumor is 2.0 cm (about 4/5 of an inch) or less in diameter and does not appear to have spread beyond the breast.
Stage II: The tumor is larger than 2.0 cm in diameter and/or it has spread to the axillary (underarm) lymph nodes on the same side as the breast cancer. In stage II breast cancer, the lymph nodes are not stuck to one another or to the surrounding tissues.
Stage III: The tumor is either larger than 5 cm (2 inches) in diameter or has spread to lymph nodes that are fixed (attached) to one another or to surrounding tissue. The cancer is also stage III if both of these findings are present.
Breast cancers of any size that have spread to the skin, the chest wall, or the internal mammary lymph nodes (located beneath the breast and inside the chest) are also included in this stage. Patients with stage III cancer show no signs that the cancer has spread to distant organs or bones, or to lymph nodes that are not near the breast, such as those above the collarbone.
Inflammatory breast cancer is classified as stage III, unless it has spread to distant organs or lymph nodes that are not near the breast, in which case it would be stage IV.
Stage IV: The cancer, regardless of its size, has metastasized to distant organs such as bones or lungs or to lymph nodes not near the breast.
Detailed Definitions of Breast Cancer T, N, M Categories and Stage Groupings
Primary tumor (T):
TX: Primary tumor cannot be assessed
T0: No evidence of primary tumor
Tis: Carcinoma in situ; intraductal carcinoma, lobular carcinoma in situ, or Paget's disease of the nipple with no associated tumor mass
T1: Tumor 2.0 cm (4/5 of an inch) or less in greatest dimension
T2: Tumor more than 2.0 cm but not more than 5.0 cm (2 inches) in greatest dimension
T3: Tumor more than 5.0 cm in greatest dimension
T4: Tumor of any size with direct extension to chest wall or skin
Regional lymph nodes (N):
NX: Regional lymph nodes cannot be assessed (for example, removed previously)
N0: No regional lymph node metastasis
N1: Metastasis to movable ipsilateral (same side as the breast cancer) axillary lymph node(s)
N2: Metastasis to ipsilateral lymph node(s) fixed to one another or to other structures
N3: Metastasis to ipsilateral internal mammary lymph nodes (located beneath the breast and inside the chest).
Distant metastasis (M):
MX: Presence of distant metastasis cannot be assessed
M0: No distant metastasis
M1: Distant metastasis is present. This includes metastasis to ipsilateral supraclavicular (above the collarbone) lymph nodes
| Stage 0 | |||
| Stage 1 | |||
| Stage IIA | T1 T2 | N1 N0 | M0 M0 |
| Stage IIB | T3 | N0 | M0 |
| Stage IIIA | T1 T2 T3 T3 | N2 N2 N1 N1, N2 | M0 M0 M0 M0 |
| Stage IIIB | Any T | N3 | M0 |
| Stage IV | |||
Breast Cancer Survival by Stage
Stage 5-year relative survival rate
0 100%
I 98%
IIA 88%
IIB 76%
IIIA 56%
IIIB 49%
IV 16%
The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. Many of these patients live much longer than 5 years after diagnosis, but 5-year rates are used as a standard way of discussing prognosis. Five-year relative survival rates exclude patients dying of other diseases from the calculations, and are considered to be a more accurate way to describe the prognosis for patients with a particular type and stage of cancer. Of course, these 5-year survival rates are based on women with breast cancer diagnosed and initially treated more than 5 years ago. Improvements in treatment often result in a more favorable outlook for recently diagnosed patients.
How Is Breast Cancer Treated?
General Comments about Treatment Information
This information represents the views of the doctors and nurses serving on the American Cancer Society's Cancer Information Database Editorial Board. These views are based on their interpretation of breast cancer treatment studies published in medical journals, as well as their own professional experience.
The treatment information in this document is not, however, official policy of the Society and is not intended as medical advice to replace the expertise and judgment of your cancer care team. It is intended to help patients and their families make informed decisions, together with their cancer care team.
Of course, your cancer care team may have reasons for suggesting a treatment plan different from these general guidelines. Don't hesitate to ask them questions about your treatment options. In addition to the information in this document, we encourage interested patients to seek out treatment information from other reliable sources.
The American Cancer Society in collaboration with the National Comprehensive Cancer Network (NCCN) provides detailed breast cancer treatment guidelines. Since 1995, experts from 17 of the nation's leading cancer centers have been developing cancer treatment guidelines for cancer care professionals.
The American Cancer Society also provides a version of these detailed guidelines, which we have written with patients and their families in mind. The version for health care professionals is available on the NCCN Web site (www.nccn.org). The version for patients and their families is available from our National Cancer Information Center (1-800-ACS-2345), our Web site (www2.cancer.org/nccn_acs/Breast), and from the NCCN telephone information center (1-888-909-NCCN).
The National Cancer Institute (NCI) provides treatment guidelines via its telephone information center and Web site. More detailed guidelines intended for use by cancer care professionals are also available on the NCI Web site.
Local Versus Systemic Therapy
Local therapy is intended to treat a tumor at the site without affecting the rest of the body. Surgery and radiation therapy are examples of local therapies.
Systemic therapy is given by mouth or directly into the bloodstream to reach cancer cells that may have spread beyond the breast. Chemotherapy, hormonal therapy, and immunotherapy are systemic therapies.
When patients who have no detectable cancer after surgery are given systemic therapy, it is called adjuvant therapy. Doctors now believe that cancer cells may break away from the primary breast tumor and begin to spread through the bloodstream even in the early stages of the disease. These cells can't be felt by physical examination or seen on x-rays or other imaging methods, and they cause no symptoms. But, they can establish new tumors in other organs or the bones. The goal of adjuvant therapy is to kill these hidden cells. Not every patient needs adjuvant therapy, however. Recommendations regarding systemic chemotherapy and hormonal therapy are discussed in the sections on these treatments and in the section on treatment by stage.
Surgical Procedures for Breast Cancer
Most women with breast cancer will have some type of surgery. Operations for local treatment include breast-conserving surgery, mastectomy, and axillary (armpit) lymph node sampling and removal. In addition, women may decide to have breast reconstruction at the same time they have the mastectomy or later on.
Breast conservation therapy: Lumpectomy removes only the breast lump and a surrounding margin of normal tissue. If examination of the tissue removed by lumpectomy finds cancer is present at its margin (edge of the piece of tissue removed), the surgeon may need to remove additional tissue. This operation is called a re-excision. Radiation therapy is given for about 6 weeks after a lumpectomy.
Partial or segmental mastectomy or quadrantectomy removes more breast tissue than a lumpectomy (up to one-quarter or more of the breast). Six to seven weeks of external beam radiation therapy is usually given after surgery. Side effects of these operations include temporary swelling and tenderness and hardness due to scar tissue that forms in the surgical site.
For most women with stage I or II breast cancer, breast conservation therapy (lumpectomy and radiation therapy) is as effective as mastectomy. Survival rates of women treated with these 2 approaches are the same. However, breast conservation therapy is not an option for all women with breast cancer and is usually not recommended for:
- Women who have already had radiation therapy to the affected breast.
- Women with 2 or more areas of cancer in the same breast that are too far apart to be removed through one surgical incision.
- Women whose initial lumpectomy or when needed, re-excision, has not completely removed the cancer.
- Women with certain connective tissue diseases such as scleroderma, that make them especially sensitive to the side effects of radiation therapy.
- Pregnant women who would require radiation while still pregnant (risking harm to the fetus).
- Women with a tumor that is larger than 5 cm (2 inches).
- Women with a cancer that is large relative to a smaller-sized breast.
Mastectomy: In a simple or total mastectomy the surgeon removes the entire breast, but does not remove underarm lymph nodes, or muscle tissue from beneath the breast. This operation is sometimes used to treat stage 0 breast cancers.
Modified radical mastectomy involves the removal of the entire breast and some of the axillary (underarm) lymph nodes. This is the most common surgery for women with breast cancer who are having the whole breast removed.
Radical mastectomy is an extensive operation removing the entire breast, axillary lymph nodes, and the pectoral (chest wall) muscles under the breast. This surgery was once very common. But because of the disfigurement and side effects it causes and because modified radical mastectomy has been proven to be as effective as radical mastectomy, it is now rarely done.
Possible side effects of mastectomy and lumpectomy include wound infection, hematoma (accumulation of blood in the wound), and seroma (accumulation of clear fluid in the wound). If axillary lymph nodes are also removed, additional side effects may occur, which are described in the section on Axillary Dissection.
Surgical Treatments for Breast Cancer
Axillary dissection: To determine if the breast cancer has spread to axillary (underarm) lymph nodes, some of these lymph nodes are removed (in an operation called axillary dissection) and examined under the microscope.
As noted previously, axillary dissection is part of a radical or modified radical mastectomy procedure, and is usually combined with a breast-conserving procedure such as lumpectomy.
Whether or not cancer cells are present in the lymph nodes under the arm is an important factor in selecting adjuvant therapy. It was once believed that removing as many lymph nodes as possible would reduce the risk of spread to other parts of the body and improve the chance of curing the cancer.
It is now known that breast cancer cells that have spread beyond the breast and axillary lymph nodes are best treated by systemic therapy. So currently, axillary dissection is used as a test to help guide other breast cancer treatment decisions. Removing cancer in the lymph node area is useful since it can no longer grow there.
The main side effect of removing axillary lymph nodes is lymphedema (swelling of the arm). About 10% to 20% of women who have underarm lymph nodes removed develop lymphedema. Ways to help prevent or reduce the effects of lymphedema are discussed in the section "What Will Happen After Treatment of Breast Cancer?" If your arm is swollen, tight, or painful after lymph node surgery, be sure to tell someone on your cancer care team promptly.
You may also have temporary or permanent limitations in arm and shoulder movement after surgery. Numbness of the upper inner arm skin is another common side effect, because the nerve controlling this skin sensation travels through the lymph node area.
Sentinel lymph node biopsy (SLNB): In this procedure, a radioactive tracer and/or a blue dye is injected into the area of the tumor. The lymphatic vessels carry the dye or radioactive material to a "sentinel node." This is the first lymph node receiving lymph from the tumor and the one most likely to contain a metastasis if the cancer has spread. If the sentinel node contains cancer, more lymph nodes are removed.
In the operating room, the surgeon, who can see the blue dye or detect the radioactivity with a Geiger counter identifies the sentinel node. This sentinel node is removed, and if it is free of cancer, additional lymph node surgery may be avoided. Using this approach, fewer patients will need to have many lymph nodes removed. Removing lymph nodes, now the standard procedure for women with breast cancer carries the risk of lymphedema, a serious side effect. Studies are in progress to determine in which patients a sentinel lymph node biopsy should be used routinely instead of an axillary dissection and how much surgical experience is necessary for an accurate SLNB. If your doctor is considering this procedure, it might be useful to ask how many sentinel node biopsies he/she has done, and whether this approach will be part of a research study.
Reconstructive surgery and breast implant surgery: These are not procedures that treat cancer, but restore the breast's appearance after mastectomy. If you are going to have a mastectomy and are thinking about having reconstruction immediately, it's important to consult with a plastic surgeon who is an expert in breast reconstruction before the surgery.
Decisions about the type of reconstruction and when it will be done depend on each individual's medical situation and personal preferences. Your breast can be reconstructed at the same time as the mastectomy (immediate reconstruction) or at a later time (delayed reconstruction). Reconstruction may use implants and/or tissue from other parts of your body (autologous tissue reconstruction). Read our document and our brochures on Breast Reconstruction After Mastectomy for more information. You may also find it helpful to talk with a woman who has had the type of reconstruction you are considering. Our Reach to Recovery volunteers can help you.
What to Expect with Surgery
For many, the thought of surgery can be very frightening. But with a better understanding of what to expect before, during, and after the operation, many fears can be relieved.
Before surgery: Today, the common use of the 2-step procedure for biopsy lets you find out if you have breast cancer within a few days of your biopsy, but the extent of the breast cancer will not be known until after the surgery for local treatment.
You usually meet with your surgeon a few days before the operation to discuss the procedure. This is a good time to ask specific questions about the surgery and review potential risks. You will be asked to sign a consent form, giving the doctor permission to perform the surgery. Take your time and review the form carefully to be certain that you understand what you are signing.
Sometimes, doctors send material for you to review in advance of your appointment, so you will have plenty of time to read it and won't feel rushed. You may also be asked to give consent for researchers to use any tissue or blood that is not needed for diagnostic purposes. Although this may not be of direct use to you, it may be very helpful to women in the future.
You may be asked to donate blood before some operations, such as a mastectomy combined with natural tissue reconstruction, if it seems that a transfusion might be needed. You might feel more secure knowing that if a transfusion is needed, you will receive your own blood. Ask your doctor about your possible need for a blood transfusion.
Your doctor will review your medical records and ask you about any medications you are taking. This is to be sure that you are not taking anything that will interfere with the surgery. For example, if you are taking a blood-thinning medication (even aspirin), you may be asked to stop taking the drug about a week or two before the surgery. Usually, you will be told not to eat or drink anything for 8 to 12 hours before the surgery, especially if you are going to have general anesthesia (will be "asleep" during surgery).
You will also meet with the anesthesiologist or nurse anesthetist, the health professional who will be giving you the anesthesia during your surgery. The type of anesthesia used depends largely on the kind of surgery being done and your medical history.
General anesthesia is usually given whenever the surgery involves a mastectomy or an axillary node dissection. You will be given an IV (intravenous line) to administer medications that may be needed during the surgery. Usually you will be hooked up to an EKG machine and have a blood pressure cuff on your arm, so your heart rhythm and blood pressure can be checked during the surgery.
Surgery: For your surgery, you may be offered the choice of an outpatient procedure or you may be admitted to the hospital. How long you stay in the hospital will depend on the surgery being performed; your overall state of health and whether you have any other medical problems; how well you do during the surgery, and how you feel after the surgery. Decisions about the length of your stay should be made by you and your doctor and not dictated by what your insurance will pay, but it is important to check your insurance coverage before surgery.
As a general rule, women having a mastectomy and/or axillary lymph node dissection stay in the hospital for 1 or 2 nights and then go home. However, some women may be placed in a 23-hour, short-stay observation unit before going home. In this situation, care is continued at home with a home care nurse visiting you to monitor and provide care.
Lumpectomy and sentinel lymph node biopsy is usually done in an outpatient surgery center and an overnight stay in the hospital is usually not necessary.
The length of the operation will depend on the type of surgery being done. For example, a mastectomy with axillary lymph node dissection will take from 2 to 3 hours. When you wake up from your surgery, you will be in the recovery room where you will stay until you are awake and your condition and vital signs (blood pressure, pulse, and breathing) are stable.
After surgery: You will have a dressing (bandage) over the surgery site. You may have one or more drains (plastic or rubber tubes) from the breast or underarm area to remove blood and lymph fluid that collects during the healing process. Care of the drains includes emptying and measuring the fluid, and identifying problems the doctor or nurse need to know about. Most drains stay in place for 1 or 2 weeks. When drainage has decreased to about 30 cc (1 fluid ounce) each day, often the drain will be removed.
Doctors rarely put the arm in a sling to hold it in place. Most doctors will want you to start moving the arm so that it won't get stiff. Women who have a lumpectomy or mastectomy are surprised by how little pain they have in the breast area. But they are less happy with the strange sensations (numbness, pinching/pulling feeling) in the underarm area. Care of the surgery site and arm should be discussed with your doctor. Written instructions about care after surgery are usually given to you and your caregivers. These instructions should include:
- The care of the surgical wound and dressing
- How to monitor drainage and take care of the drains
- How to recognize signs of infection
- When to call the doctor or nurse
- When to begin using the arm and how to do arm exercises to prevent stiffness
- When to resume wearing a bra
- When to begin using a prosthesis and what type to use (after mastectomy)
- What to eat and not to eat
- Use of medications, including pain medications
- Any restrictions of activity
- What to expect regarding sensations or numbness in the breast and arm
- What to expect regarding feelings about body image
- A follow-up appointment and referral to a Reach to Recovery volunteer. Through our Reach to Recovery program, a specially trained volunteer who has had breast cancer can provide information, comfort, and support. (See our document on Reach to Recovery for more information.)
Most patients will see their doctor within 7 to 14 days following the surgery. Your doctor should explain the results of your pathology report and talk to you about the need for further treatment. If you will need more treatment, you will be referred to a medical oncologist and/or radiation oncologist.
Chemotherapy
Chemotherapy is treatment with anticancer drugs that may be given intravenously (injected into a vein) or by mouth. The drugs travel through the bloodstream to reach cancer cells anywhere in the body. When used as adjuvant therapy after breast conservation therapy or mastectomy, chemotherapy can significantly reduce the risk of breast cancer recurrence.
Chemotherapy can also be used as the main treatment for women whose cancer already has spread outside the breast and underarm area at the time it is diagnosed, or spreads after initial treatments.
Neoadjuvant chemotherapy is given before surgery. Neoadjuvant chemotherapy often shrinks the cancer so that surgery can remove cancers that would otherwise be too large for complete surgical removal. In other cases, shrinking a large cancer with neoadjuvant chemotherapy makes breast conservation therapy an option. Another advantage of neoadjuvant chemotherapy is that doctors can see how the cancer responds to chemotherapy. If the tumor does not shrink, then different chemotherapy drugs may be substituted. Chemotherapy is given in cycles, with each period of treatment followed by a recovery period. The total course of chemotherapy lasts 3 to 6 months depending on the regimens used.
A combination of anticancer drugs is generally more effective than a single drug. The most commonly used combinations are:
- Cyclophosphamide (Cytoxan), methotrexate (Amethopterin, Mexate, Folex), and fluorouracil (Fluorouracil, 5-Fu, Adrucil) [abbreviated CMF]
- Cyclophosphamide, doxorubicin (Adriamycin), and fluorouracil [abbreviated CAF]
- Doxorubicin (Adriamycin) and cyclophosphamide [abbreviated AC]
- Doxorubicin (Adriamycin) and cyclophosphamide with paclitaxel (Taxol)
- Doxorubicin (Adriamycin), followed by CMF
- Cyclophosphamide, epirubicin (Ellence), and fluorouracil
Other chemotherapy drugs used for treating women with breast cancer include docetaxel (Taxotere), vinorelbine (Navelbine), and gemcitabine (Gemzar), and capecitabine (Xeloda).
The side effects of chemotherapy depend on the type of drugs, the amount taken, and the length of treatment. Temporary side effects might include fatigue, nausea and vomiting, loss of appetite, hair loss, and mouth sores. Changes in the menstrual cycle may be temporary or permanent. Because chemotherapy can damage the blood-producing cells of the bone marrow, patients may have low blood cell counts. This can result in an increased chance of infection (due to a shortage of white blood cells), bleeding or bruising after minor cuts or injuries (due to a shortage of blood platelets), and fatigue (due to low red blood cell counts).
There are very effective remedies for many of the temporary side effects of chemotherapy. For example, there are several drugs that can prevent or reduce nausea and vomiting. A group of drugs called growth factors can help the patient's bone marrow recover after chemotherapy and can treat problems caused by low blood counts.
Premature menopause (not having any more menstrual periods) and infertility (not being able to become pregnant) are potential permanent complications of chemotherapy. The older a woman is when she receives chemotherapy, the more likely it is that she will become infertile or menopausal as a result.
Adriamycin (doxorubicin) may cause permanent heart damage if used for a long time or in high doses, but doctors carefully control the dose of this drug and use echocardiograms and other heart tests in order to monitor the heart and will stop the medication at the first sign of damage.
Very rarely, years or decades after treatment for breast cancer, certain chemotherapy drugs may cause acute myeloid leukemia, a life-threatening cancer of white blood cells. Chemotherapy's benefits in preventing many breast cancers from coming back and in saving lives from breast cancer far exceed the risk of this serious but rare complication.
Radiation Therapy
Radiation therapy is treatment with high-energy rays or particles that destroy cancer cells. This treatment may be used to destroy cancer cells that remain in the breast, chest wall, or underarm area after surgery. Less often, radiation is used to reduce the size of a tumor before surgery. In some cases, the area treated by radiation therapy may also include supraclavicular lymph nodes (nodes above the collarbone) and internal mammary lymph nodes (nodes beneath the sternum ["breast bone"] in the center of the chest, inside the chest cavity). When given after surgery, radiation therapy is usually not started until the tissues have been able to heal for about a month.
External beam radiation: This is the usual type of radiation therapy for women with breast cancer. The radiation is focused from a source outside the body on the area affected by the cancer. It is much like getting a diagnostic x-ray, but the radiation is more intense.
Before your treatments start, the radiation team carefully takes measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. They will make some ink marks on your skin that they will use later as a guide to focus the radiation on the right area. Patients are usually treated 5 days a week in an outpatient center for about 6 weeks, with each treatment lasting a few minutes. The procedure itself is painless. Deodorants and antiperspirants can interfere with external beam radiation therapy of the underarm area, and so you should avoid using them until treatments are complete.
The main side effects of external beam radiation therapy are swelling and heaviness in the breast, sunburn-like skin changes in the treated area, and fatigue. You should avoid exposing the treated skin to the sun, because it can make the skin changes worse. These changes to the breast tissue and skin usually go away in 6 to 12 months.
In some women, the breast becomes smaller and firmer after radiation therapy. Radiation therapy of axillary lymph nodes also can cause lymphedema. (This is discussed in "What Will Happen After Treatment For Breast Cancer?"). Radiation therapy is usually not given during pregnancy because it can harm a fetus.
Brachytherapy: Brachytherapy, also known as internal radiation, is another way to deliver radiation therapy. Instead of aiming radiation beams from outside the body, radioactive substances are placed directly into the breast tissue next to the cancer. This method, currently considered to be experimental, is discussed in the section "What's New in Breast Cancer Research and Treatment?"
Hormone Therapy
Estrogen, a hormone produced by women's ovaries, promotes growth of some breast cancers, particularly those with detectable amounts of estrogen receptor protein. Several approaches to blocking the effect of estrogen or lowering estrogen levels are used to treat breast cancer.
Tamoxifen: The antiestrogen drug used most often is tamoxifen (Nolvadex). It is taken daily in pill form, usually for 5 years. Studies show that use of tamoxifen as adjuvant therapy after surgery can reduce the chances of the cancer coming back. Recent studies have clearly shown that regardless of their age, this drug helps women with early breast cancer. Tamoxifen may also be used to treat metastatic breast cancer.
Some studies have shown a slight increase of early stage endometrial cancer (cancer of the lining of the uterus) among women taking tamoxifen, with the risk increasing if the drug is taken for more than 5 years. This cancer is usually diagnosed at a very early stage and is almost always curable by surgery. Tell your doctor immediately about any unusual vaginal bleeding (a common symptom of endometrial cancer). Most uterine bleeding is not due to cancer, but this symptom always needs prompt evaluation.
Other side effects of tamoxifen may include weight gain, hot flashes, and mood swings. Blood clots and cataracts are rare but serious side effects. Nonetheless, for most women with breast cancer, the benefits of taking tamoxifen far outweigh the risks.
Raloxifene: Raloxifene is a drug that, like tamoxifen, blocks the effect of estrogen on breast tissue and breast cancer. It is currently being tested to see if it can reduce women's risk of developing breast cancer. Until more testing is done, Raloxifene is not recommended as hormonal therapy for women who have already been diagnosed with breast cancer.
Toremifene: Toremifene (Fareston), another antiestrogen drug closely related to tamoxifen, may be an option for postmenopausal women with breast cancer that has metastasized. Toremifene is an antiestroge