Oncologist-approved cancer information from the American Society of Clinical Oncology

Breast Cancer


Last Updated: November 19, 2009

This section has been reviewed and approved by the Cancer.Net Editorial Board,  09/09

Overview

In the United States, breast cancer is the most common cancer occurring in women (excluding skin cancer) and the second most common cause of death from cancer in women, after lung cancer. Men can also develop breast cancer, but male breast cancer is rare, accounting for less than 1% of all breast cancer cases. Cancer begins when normal cells in the breast begin to change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body).

The breast is mainly composed of fatty tissue. Within this tissue is a network of lobes, which are made up of tiny, tube-like structures called lobules that contain milk glands. Tiny ducts connect the glands, lobules, and lobes, carrying the milk from the lobes to the nipple, located in the middle of the areola (darker area that surrounds the nipple of the breast). Blood and lymph vessels run throughout the breast; blood nourishes the cells, and the lymph system drains bodily waste products. The lymph vessels connect to lymph nodes, which are tiny, bean-shaped organs that normally help fight infection.

About 90% of all breast cancer cases start in the ducts or lobes. Almost 75% of all breast cancers begin in the cells lining the milk ducts and are called ductal carcinomas. Cancer that begins in the lobules is called lobular carcinoma. If the disease has spread outside of the duct and into the surrounding tissue, it is called invasive or infiltrating ductal carcinoma. If the disease has spread outside of the lobule, it is called invasive or infiltrating lobular carcinoma. Disease that has not spread is called in situ, meaning “in place.” The course of in situ disease, as well as its treatment, depends on whether it is ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS).

Currently, oncologists recommend that DCIS, which accounts for the majority of in situ breast cancers, be surgically removed to help prevent the cancer from changing into an invasive breast cancer and potentially spreading to other parts of the breast or the body. In addition to surgery, radiation therapy and hormone therapy may be recommended for DCIS (see Treatment for more information).

LCIS is not considered cancer and is usually monitored by the doctor. LCIS is a risk factor for breast cancer (see the Risk Factors section).

Other, less common cancers of the breast include medullary, mucinous, tubular, metaplastic, and papillary breast cancer. Inflammatory breast cancer is a faster-growing type of cancer that accounts for about 1% to 5% of all breast cancers. It may be misdiagnosed as a breast infection because there is often swelling of the breast and redness of the breast skin. Paget’s disease is a type of in situ cancer that can begin in the ducts of the nipple. The skin often appears scaly and may be itchy.

Cancer may begin as a single, genetically abnormal cell. As this one cell divides, it eventually becomes a tumor and develops a blood supply to nourish its continued growth. At some point, cells may break off from the primary mass and move to other parts of the body in a process called metastasis.

Breast cancer spreads when breast cancer cells move to other sites in the body through the blood vessels and/or lymph vessels. A common site of spread is the regional lymph nodes. The lymph nodes can be axillary (located under the arm), cervical (located in the neck), or supraclavicular (located just above the collarbone). The most common sites of distant metastasis are the bones, lungs, and liver. Less commonly, breast cancer may spread to the brain. The cancer can also recur (come back after treatment) locally in the skin, in the same breast (if it was not removed as part of treatment), other tissues of the chest, or elsewhere in the body.

Most of the time, breast cancer is diagnosed and treated before metastasis occurs. According to the latest data from the National Cancer Institute (NCI), 61% of breast cancers are diagnosed while the cancer is still in the breast, 31% are diagnosed after the cancer has spread to nearby lymph nodes or just outside the breast, and 6% are diagnosed once the cancer has metastasized beyond the adjoining lymph nodes to distant sites.

Statistics

In 2009, an estimated 192,370 women in the United States will be diagnosed with invasive breast cancer, and 62,280 women will be diagnosed with in situ breast cancer. An estimated 1,910 men in the United States will be diagnosed with breast cancer. It is estimated that 40,610 deaths (40,170 women, 440 men) from this disease will occur this year.

If the cancer is limited to the breast, the five-year relative survival rate (percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) is 98%. If the cancer has spread to the regional lymph nodes, the five-year relative survival rate is 84%. If the cancer has spread to a distant site, the five-year relative survival rate is 27%. Even if the cancer is found at a more advanced stage, new treatments enable many people with breast cancer to experience the same quality of life as before their diagnosis.

It is important to note that these statistics are averages, and each individual’s risk depends upon numerous factors, including the size of the tumor and the number of positive lymph nodes (lymph nodes that contain cancer; this is called “node-positive cancer,” see Diagnosis). The survival rate is higher and the chance of recurrence is lower for a smaller tumor with negative lymph nodes (lymph nodes that do not contain cancer; this is called “node-negative cancer”). The recurrence rate increases with an increase in tumor size and number of positive lymph nodes.

Since 1990, the number of women who have died of breast cancer has declined steadily each year. In women younger than 50, there has been a decrease of 3% per year; in women age 50 and older, the decrease has been 2% per year. Currently, there are about two and a half million women living in the United States who have been diagnosed with and treated for breast cancer.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with breast cancer. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Statistics adapted from the American Cancer Society's publication, Cancer Facts & Figures 2009.

Find out more about basic cancer terms used in this section.

Medical Illustrations

Breast Cancer

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Risk Factors

A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as physical activity and diet, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health care choices.

Many cases of breast cancer occur in women with no obvious risk factors. This means that all women need to be aware of possible changes in their breasts and schedule a clinical breast examination (breast exam performed by a doctor or other health care professional) and mammogram (x-ray of the breast that can detect a tumor that is too small to be felt). It is likely that multiple risk factors influence the development of breast cancer.

The following factors may raise a woman’s risk of developing breast cancer:

Age. The risk of developing breast cancer increases as a woman ages, with most cases developing in women over 50.

Race and ethnicity. Although white women are more likely to develop breast cancer, black women are more likely to die from the disease. Reasons for survival differences are unclear and probably involve both socioeconomic and biologic factors.

Personal history of breast cancer. A woman who has had breast cancer in one breast has a 1% to 2% chance per year of developing a second breast cancer in her opposite breast.

Family history of breast cancer. Women who have a first-degree relative (mother, sister, daughter) diagnosed with breast cancer are at increased risk for the disease. More than one first-degree relative with breast cancer elevates that risk, especially if the cancer occurred before menopause. Women who have a second-degree relative (aunt, niece, grandmother, granddaughter) diagnosed with breast cancer also have a higher risk of breast cancer. The father’s (paternal) side of the family should also be considered equally to the mother’s (maternal) side when evaluating a family history. For example, you may be at higher risk if your father’s sister or mother had breast cancer.

Genetic predisposition. Mutations to the breast cancer genes 1 or 2 (BRCA1 or BRCA2) are associated with increased breast cancer risk. Blood tests (genetic testing) are available to test for known mutations to these genes, but are not recommended for everyone and only after a person has received appropriate genetic counseling. Men in families may also carry these gene mutations. Breast cancer in male family members significantly increases the risk of having a family breast cancer gene. Researchers estimate that breast cancers due to inherited genes with high risk for developing cancer make up only 5% to 10% of all breast cancers. If a woman learns she has these genetic mutations, there are steps she can take to lower her risk of breast and ovarian cancers. Learn more about the genetics of breast cancer.

Personal history of ovarian cancer. A history of ovarian cancer can increase a woman’s risk of breast cancer. Breast cancer gene mutations, such as BRCA1 or BRCA2, greatly increase the risk of both ovarian and breast cancers.

Estrogen and progesterone exposure. Estrogen and progesterone are hormones in women that control the development of secondary sex characteristics (such as breast development) and pregnancy. A woman’s production of estrogen and progesterone decreases at menopause. Prolonged exposure to these hormones increases breast cancer risk.

  • Women who began menstruating before age 11 or went through menopause after age 55 have a higher risk of breast cancer because their breast cells have been exposed to estrogen and progesterone for a longer time.

  • Women who have their first pregnancy after age 35 or who have never had a full-term pregnancy have a higher risk of breast cancer. Pregnancy may protect against breast cancer, because it pushes breast cells into their final phase of maturation.

  • Recent use (within the past five years) and long-term use (several years or more) of postmenopausal hormone replacement therapy increases a woman’s risk of breast cancer.

  • Removing the ovaries, a source of estrogen and progesterone, can greatly lower breast cancer risk; this procedure is called an oophorectomy. Some women with inherited BRCA1 or BRCA2 mutations undergo prophylactic oophorectomy as a preventive measure to lower their risk of breast and ovarian cancers.

  • There is no clear link between the use of oral contraceptives (birth control pills) to prevent pregnancy and development of breast cancer.

Atypical hyperplasia of the breast. This condition increases the risk of breast cancer and is characterized by abnormal, but not cancerous, cells found in a breast biopsy.

LCIS. As explained in the Overview section, this condition describes abnormal cells found in the lobules or glands of the breast. LCIS increases the risk of developing invasive breast cancer (cancer that spreads into surrounding tissues). Talk with your doctor about the best way to monitor this condition.

Lifestyle factors. As with other types of cancer, studies continue to show that various lifestyle factors may contribute to the development of breast cancer.

  • Recent studies have shown that postmenopausal women who are obese have an increased risk of breast cancer.

  • Exercise lowers hormone levels, alters metabolism, and boosts the immune system. Increased physical activity is associated with a decreased risk of developing breast cancer.

  • Regularly drinking more than one to two alcoholic drinks per day raises the risk of breast cancer.

Radiation. High doses of radiation may increase a woman’s risk of breast cancer. An increased risk of breast cancer has been observed in long-term survivors of atomic bombs, people with lymphoma treated with radiation therapy to the chest, people undergoing large numbers of x-rays (such as for tuberculosis or to treat residual thymic disease or acne), nonmalignant (noncancerous) conditions of the spine, and children treated with radiation therapy for ringworm. However, it should be noted that the amount of radiation a woman receives during a yearly mammogram does not seem to increase breast cancer risk and any slight risk is outweighed by the benefits of screening.

Prevention

No intervention is 100% guaranteed to prevent breast cancer occurrence. However, women have several options to reduce the risk of developing breast cancer.

  • For women with especially strong family histories of breast cancer (such as those with BRCA1 or BRCA2 mutations), a prophylactic mastectomy (preventive removal of the breasts) may be considered. This appears to reduce the risk of developing breast cancer by at least 95%. These women may also consider a prophylactic oophorectomy (removal of the ovaries), which can reduce the risk of developing breast and ovarian cancers.

  • Women who are at higher than normal risk for developing breast cancer may consider chemoprevention (the use of drugs to reduce breast cancer risk). Two drugs, tamoxifen (Nolvadex) and raloxifene (Evista), are approved to lower breast cancer risk. These drugs are called selective estrogen receptor modulators (SERMs). A SERM is a medication that blocks estrogen receptors in some tissues and not others. Women that have gone through menopause (postmenopausal) and women who have not (premenopausal) may take tamoxifen, whereas raloxifene is only approved for postmenopausal women. Each drug also has different side effects; talk with your doctor about whether you may benefit from chemoprevention for breast cancer. Read more about drugs to reduce breast cancer risk.

  • Other ways to lower your risk of breast cancer include getting regular physical activity, staying at a normal weight, and limiting the amount of alcohol you drink. Learn about more lifestyle changes to prevent cancer.

Several breast cancer risk assessment tools have been developed to help a woman estimate her chance of developing breast cancer. The best studied is the Gail model (www.cancer.gov/bcrisktool). After entering some personal and family information, the tool provides a five-year and lifetime estimate of the risk of developing invasive breast cancer. Because it only asks for information about breast cancer in first-degree family members (mother, sister) and doesn’t include their age at diagnosis, the tool works best at estimating risk in women without a strong inherited breast cancer risk.

For most women, regular mammography and clinical breast examinations can help find early signs of breast cancer. In addition, women should become familiar with their own breasts. Checking your own breasts for lumps and changes with breast self-examination may help if performed correctly. Talk with your doctor for more information.

Screening guidelines

The U.S. Preventive Services Task Force (USPSTF) recommends that women 50 to 74 years old undergo mammography every two years, and the American Cancer Society (ACS) recommends yearly mammography beginning at age 40. Mammography is the best tool doctors have to screen for breast cancer and can detect a tumor that is too small to be felt. All women should talk with their doctors about mammography and decide on an appropriate screening schedule.

Occasionally, mammograms may miss a cancer. Other methods of breast imaging, such as ultrasound and magnetic resonance imaging (MRI), are not regularly used for screening purposes. However, they may be helpful for evaluating women at a higher risk for breast cancer, including women with a BRCA mutation and women who received radiation therapy for Hodgkin lymphoma. These other screening methods may also be used for those with a suspicious finding on physical examination or mammography. If there are suspicious findings on physical examination, further evaluation is necessary, even if the mammogram is interpreted as normal.

The USPSTF and ACS differ on their recommendations for clinical breast examination. The USPSTF recommends a clinical breast examination along with mammography, and the ACS recommends a clinical breast examination every one to three years until age 40, then annually. Breast self-examination has not been shown to lower deaths from breast cancer, but it is important for women to become familiar with their breasts so that they can be aware of any changes. Women are encouraged to discuss the frequency of screening with their doctors. Learn more about ASCO’s perspective on the 2009 USPSTF mammography screening guidelines.

Symptoms

Women with breast cancer may experience breast abnormalities or symptoms, but many women do not show any of these findings at the time of diagnosis. Many times, breast symptoms can be caused by a medical condition that is not cancer. If you are concerned about a breast finding or symptom, please talk with your doctor.

The signs and symptoms to look for include:

  • New lumps (many women normally have lumpy breasts) or a thickening in the breast or under the arm

  • Nipple tenderness, discharge, or physical changes (such as a nipple turned inward, a persistent sore, or a change in the size or shape of the breast)

  • Skin irritation or changes, such as puckers, dimples, scaliness, or new creases

  • Warm, red, swollen breasts with a rash resembling the skin of an orange (called peau d'orange)

  • Pain in the breast (usually not a symptom of breast cancer, but should be reported to a doctor)

Diagnosis

Doctors use many tests to diagnose cancer and determine if it has metastasized. Some tests may also find out which treatments may be the most effective. For most types of cancer, a biopsy (the removal of a small amount of tissue for examination under a microscope) is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:

  • Age and medical condition

  • The type of cancer suspected

  • Severity of symptoms

  • Previous test results

The diagnosis of breast cancer usually begins when a woman or her doctor discovers a mass or abnormal calcification (tiny spot of calcium usually found on an x-ray) on a screening mammogram, or an abnormality in the woman’s breast by clinical examination or self-examination. Several tests may be done to confirm a diagnosis of breast cancer. Not every person will have all of these tests.

In addition to screening mammography, the following tests may be used to diagnose breast cancer:

Imaging tests

Diagnostic mammography. Diagnostic mammography is similar to screening mammography except that more views (pictures) of the breast are taken, and it is often used when a woman is experiencing signs, such as nipple discharge or a new lump. Diagnostic mammography may also be used if something suspicious is found on a screening mammogram.

Ultrasound. An ultrasound uses high-frequency sound waves to create an image of the breast tissue. An ultrasound may distinguish between a solid mass, which may be cancer, and a fluid-filled cyst, which is usually not cancer.

MRI. An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium (a special dye) may be injected into a patient’s vein to create a clearer picture.

An MRI may be used once a woman has been diagnosed with cancer to check the other breast for cancer, but the benefit of this is questionable. It may also be used for screening. According to the ACS, women at high risk for breast cancer (for example, women with BRCA gene mutations or a strong family history of breast cancer) should receive MRI screening along with a mammogram. MRI is often better than mammography and ultrasound at finding a small mass in a woman’s breast, especially for women with very dense breast tissue. However, an MRI has the risk of having a higher rate of false-positive test results (a test result that indicates cancer when there is no cancer present) and may result in more biopsies and other tests. In addition, an MRI does not show calcifications, which could indicate in situ breast cancer (DCIS). Talk with your doctor for more information.

Surgical tests

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). A biopsy is specified by the technique and/or size of needle used to collect the tissue sample.

  • A fine needle aspiration biopsy (FNAB) uses a small needle to remove a small sample of cells.

  • A core needle biopsy uses a larger needle to remove a larger sample of tissue. This is usually the preferred biopsy technique for determining whether a physical exam or imaging finding is cancer. A vacuum-assisted biopsy removes multiple large cores of tissue.

  • A surgical biopsy removes the largest amount of tissue. This biopsy may be incisional (removal of part of the lump) or excisional (removal of the entire lump). Because definitive surgery is optimally done after a cancer diagnosis has been made, a surgical biopsy is usually not the recommended approach to determining whether an abnormality is cancerous. If a surgical biopsy confirms cancer, then further surgery is usually required to remove remaining cancer in the breast and evaluate the lymph nodes. Therefore, in order to keep surgery to one operation, it’s best when a patient receives a core biopsy to diagnose the cancer, followed by the type of cancer surgery with the best chance at removing all of the disease, as determined by the doctor.

  • Image-guided biopsy is used when a distinct lump can't be felt, but an abnormality is seen on a radiologic image, such as a mammogram. During this procedure, a needle is guided to the area of concern with the help of mammography, ultrasound, or MRI. A stereotactic biopsy is performed with mammography guidance. A small metal clip may be put into the breast to mark the site of biopsy, in case the sample tissue proves cancerous and additional surgery is required. An image-guided biopsy can be done using a fine needle, core, or vacuum-assisted biopsy, depending on the amount of tissue being removed.

If cancer is diagnosed, surgery is needed to remove the cancer in the breast and evaluate the lymph nodes for the presence of cancer (discussed in Treatment). The goal is to achieve clear surgical margins (no cancer cells at the edge of the tissue removed during surgery). If lymph nodes show evidence of cancer, the cancer is called lymph node-positive breast cancer (or node-positive, for short); if the lymph nodes do not show evidence of cancer, the cancer is called lymph node-negative breast cancer (or node-negative, for short). Additional information about lymph node evaluation can be found in Staging.

Testing the tissue

The pathologist tests the tissue from the biopsy and the surgery for the following to help guide treatment decisions

Tumor features. Examination of the tumor under the microscope determines if it is invasive or in situ; ductal or lobular; grade (how different the cancer cells look from healthy cells); and whether the cancer has spread to the lymph nodes. The margins (edges) of the tumor are also examined.

Estrogen receptor (ER) and progesterone receptor (PR) tests. Breast cancer cells with these receptors depend on the hormones estrogen and progesterone to grow. The presence of these receptors helps determine both the patient’s prognosis (chance of recovery) and whether the cells are likely to respond to hormone therapy. Generally, ER-positive or PR-positive tumors respond to hormone therapy. About 75% to 80% of breast cancers express estrogen and/or progesterone receptors.

HER2 tests. There is too much of the protein called human epidermal growth factor receptor two (HER2) in about 20% to 25% of invasive breast cancers, and this type of cancer is called HER2-positive cancer. The HER2 status helps determine whether a drug, such as trastuzumab (Herceptin), might be useful for treating breast cancer. Read ASCO’s recommendations for HER2 testing for breast cancer.

If a person’s tumor does not have ER, PR, and HER2, the tumor is called triple-negative. Triple-negative breast cancers comprise about 15% of invasive breast cancers. This subtype of breast cancer is frequently more aggressive, and seems to be more common among black women and younger women diagnosed with breast cancer.

Testing a tumor’s genes

Tests that look at the biology of the tumor are becoming more common to understand more about a woman’s breast cancer. The tests below look at the expression of genes in a tumor sample to predict the risk of cancer recurrence. A person with a higher risk of recurrence will likely receive additional treatment, while a person with a lower risk of recurrence can avoid extra treatment and its possible side effects. For more information about these tests, what they mean, and how it might affect your treatment plan, talk with your doctor.

  • Oncotype Dx is a test that evaluates 21 genes to estimate the risk of distant recurrence (return of the cancer in a place other than the breast) at 10 years for women with stage I or stage II (see Staging) node-negative, ER-positive breast cancer treated with hormone therapy alone. It is mainly used to help make decisions about whether chemotherapy should be added to a person’s treatment.

  • Mammaprint is another, similar test using about 70 genes to predict the risk of the cancer coming back. It is approved in early-stage, low-risk breast cancer. Although it is approved by the U.S. Food and Drug Administration (FDA) for estimating the risk of recurrence in early-stage breast cancer, it requires a frozen sample of tumor, which is not how cancer samples are generally collected and stored in the United States, thereby limiting its use.

Blood tests

The doctor may also need to do blood tests to learn more about the cancer.

A serum chemistry panel is frequently done to evaluate blood electrolytes (minerals in your body, such as potassium and calcium) and enzymes (specialized proteins) that can be abnormal if cancer has spread. However, it is important to note that many noncancerous conditions can cause variations in these tests, and they are not specific to cancer.

  • Alkaline phosphatase is an enzyme that can be associated with disease that has spread to the liver, bone, or bile ducts.

  • Blood calcium levels can be elevated if cancer has spread to the bone.

  • Total bilirubin count and the enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST)evaluate liver function. High levels of any of these substances can indicate liver damage, a signal of possible spread to that organ.

Blood tumor marker tests

A serum tumor marker (also called a biomarker) is a substance found in a person's blood that can be associated with the presence of cancer. An elevated serum tumor marker may indicate an abnormal process in the body, which could be due to cancer or a noncancerous condition. Tumor marker testing is not usually recommended in early-stage breast cancer, but these markers may be useful in the follow-up care of recurrent or metastatic disease. Common tumor marker assays in breast cancer include CA27.29, CA15-3, and CEA. Learn more about tumor markers for breast cancer.

Additional tests

The doctor may order additional tests (depending on the individual’s medical history and results of the physical examination) to evaluate the stage of the cancer. Read Staging for more information. These tests are generally only recommended for patients with more advanced stage disease.

  • A chest x-ray may be used to look for cancer that has spread from the breast to the lung.

  • A bone scan may be used to look for spread to the bones. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark.

  • A computed tomography (CT or CAT) scan may be used to look for distant tumors. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium is injected into a patient’s vein to provide better detail.

  • A positron emission tomography (PET) scan may be used to determine whether the cancer has spread. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body and absorbed by the organs or tissues being studied. This substance gives off energy that is detected by a scanner, which produces the images.

Learn more about what to expect when having common tests, procedures, and scans.

Find out more about common terms used during a diagnosis of cancer.

Staging With Illustrations

Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis. There are different stage descriptions for different types of cancer.

One tool that doctors use to describe the stage is the TNM system. This system uses three criteria to judge the stage of the cancer: the size of the tumor itself, the presence of cancer in the lymph nodes around the tumor, and whether the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero), which is non-invasive ductal carcinoma in situ (DCIS), and stages I through IV (one through four) for invasive breast cancer. The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments.

TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:

  • How large is the primary tumor and where is it located? (Tumor, T)

  • Has the tumor spread to the lymph nodes? (Node, N)

  • Has the cancer metastasized to other parts of the body? (Metastasis, M)

Tumor. Using the TNM system, the “T” plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are divided into smaller groups that help describe the tumor in even more detail.

TX: The primary tumor cannot be evaluated.

T0: There is no evidence of cancer in the breast.

Tis: Refers to carcinoma (cancer) in situ. In this case, the cancer is confined within the natural boundaries of the breast tissue and has not spread into the surrounding tissue of the breast. There are three types of breast carcinoma in situ:

Tis (DCIS): Ductal carcinoma in situ (DCIS) is a precancer, but it can later develop into an invasive type of breast cancer. A designation of DCIS means that only a few cancer cells have been found in breast ducts and have not spread past the layer of tissue where they began.

Tis (LCIS): Lobular carcinoma in situ (LCIS) describes abnormal cells found in the lobules or glands of the breast. LCIS is not cancer, but it increases the risk of developing invasive breast cancer.

Tis (Paget’s): Paget’s disease of the nipple is a rare form of early breast cancer. This designation is used only if there is Paget’s disease but no tumor present. If there is a tumor, it is classified according to the size of the tumor.

T1: A tumor in the breast is 2 centimeters (cm) or smaller in size at its widest dimension.

T1mic: Microinvasion, or micrometastases, means a few cancer cells have spread to surrounding tissue, but none larger than 0.1 cm.

T1a: The tumor is larger than 0.1 cm but smaller than 0.5 cm.

T1b: The tumor is larger than 0.5 cm but smaller than 1 cm.

T1c: The tumor is larger than 1 cm but not larger than 2 cm.

T2: The tumor is larger than 2 cm but not larger than 5 cm.

T3: The tumor is larger than 5 cm.

T4: The tumor has spread to the chest wall or to the skin or is diagnosed as inflammatory breast cancer.

T4a: The tumor has spread into the chest wall.

T4b: There is edema (swelling), thickening of the skin (as in peau d'orange), or ulceration (a sore, painful area where the breast skin/tissue is breaking down) of the breast skin or surrounding skin nodules of the same breast.

T4c: There are signs of both T4a and T4b.

T4d: Refers to inflammatory carcinoma. This is an aggressive type of breast cancer where the breast is red, swollen, and warm.

Node. The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes located under the arm, above and below the collarbone, and under the breastbone are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes.

NX: The lymph nodes cannot be evaluated.

N0: No cancer was found in the lymph nodes.

N1: The cancer has spread to one to three axillary lymph nodes.

N2: The cancer has spread to four to nine lymph nodes under the arm or to the internal mammary lymph nodes (lymph nodes to the right or left of the sternum [breastbone] on the inside of the chest) without axillary node involvement.

N2a: The cancer has spread to four to nine lymph nodes under the arm (at least one tumor deposit is larger than 2 mm).

N2b: The cancer has spread only to the internal mammary lymph nodes.

N3: The cancer has spread to 10 or more lymph nodes under the arm or to the infraclavicular lymph nodes (located under the collarbone) or to the internal mammary nodes with axillary node involvement.

N3a: The cancer has spread to 10 or more lymph nodes under the arm or to the infraclavicular lymph nodes.

N3b: The cancer has spread to internal mammary nodes and axillary nodes.

N3c: The cancer has spread to the supraclavicular lymph nodes.

If there is cancer in the lymph nodes, it also helps doctors to plan treatment to know how many lymph nodes are involved. The pathologist can determine the number of lymph nodes affected by cancer.

Distant metastasis. The “M” in the TNM system indicates whether the cancer has spread to other parts of the body.

MX: Distant spread cannot be evaluated.

M0: The disease has not metastasized.

M1: There is metastasis to another part of the body.

Cancer stage grouping

Doctors assign the stage of the cancer by combining the T, N, and M classifications.

Stage 0: Disease that has not spread past the natural boundaries of the breast. It is also called noninvasive cancer.

Stage I: The tumor is small and has not spread to the lymph nodes (T1, N0, M0).

Stage I Breast Cancer

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Stage IIa: Any one of these conditions:

  • The tumor is smaller than or equal to 2 cm and has spread to the axillary lymph nodes under the arm (T1 or T1mic, N1, M0).

  • The tumor is larger than 2 cm but not larger than 5 cm and has not spread to the axillary lymph nodes (T2, N0, M0).

  • There is no evidence of a tumor in the breast, but there is cancer in the axillary lymph nodes (T0, N1, M0).

Stage IIa Breast Cancer

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Stage IIb: Any one of these conditions:

  • The tumor is larger than 2 cm but not larger than 5 cm and has spread to the axillary lymph nodes (T2, N1, M0).

  • The tumor is larger than 5 cm but has not spread to the axillary lymph nodes (T3, N0, M0).

Stage IIb Breast Cancer

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Stage IIIa: Any of these conditions:

  • The tumor is smaller than 5 cm and has spread to the axillary lymph nodes (T1, N2, M0 or T2, N2, M0).

  • The tumor is larger than 5 cm and has spread to the axillary lymph nodes (T3, N1, M0 or T3, N2, M0).

Stage IIIa Breast Cancer

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Stage IIIb: The tumor has spread to the chest wall or caused swelling or ulceration of the breast or is diagnosed as inflammatory breast cancer. It may or may not have spread to the lymph nodes under the arm, but has not spread to other parts of the body (T4, N0, M0; T4, N1, M0; or T4, N2, M0).

Stage IIIb Breast Cancer

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Stage IIIc: A tumor of any size has not spread to distant parts of the body but has spread to the lymph nodes in the N3 group (any T, N3, M0).

Stage IIIc Breast Cancer

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Stage IV: The tumor can be any size and has spread to distant sites in the body, usually the bones, lungs or liver, or chest wall (any T, any N, M1).

Stage IV Breast Cancer

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Recurrent: Recurrent cancer is cancer that comes back after treatment.

Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual Sixth Edition (2002) published by Springer-Verlag New York, www.cancerstaging.net

Treatment

The treatment of breast cancer depends on the size and location of the tumor, whether the cancer has spread, and the person’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan

This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, read the Clinical Trials section.

Overview of breast cancer treatment

The biology and behavior of a breast cancer affects the treatment. Some tumors are small but grow fast, while others are large and grow slower. When planning the treatment for breast cancer, the doctor will consider many factors, including:

  • The stage and grade of the tumor

  • The tumor’s hormone receptor status (ER, PR) and HER2 status (see Diagnosis)

  • The patient’s age and general health

  • The patient’s menopausal status

  • The presence of known mutations in inherited breast cancer genes (BRCA1 or BRCA2)

Even though the doctor will specifically tailor the treatment for each patient and the breast cancer, there are some general steps for treating breast cancer.

For both DCIS and early-stage invasive breast cancer, doctors generally recommend surgery to remove the tumor. To ensure that the entire tumor is removed, the surgeon will also remove a small area of tissue around the tumor. Although surgery aims to remove all of the visible cancer, it is known that many times microscopic cells can be left behind, either in the breast or elsewhere.

The next step in the management of early-stage breast cancer is to lower the risk of recurrence (return of the cancer) and to get rid of any hidden remaining cancer cells. This is called adjuvant therapy. Adjuvant therapies include radiation therapy, chemotherapy, hormone therapy, and/or targeted therapy (see below for more information on these types of treatment). The need for adjuvant therapy is determined based on an estimate of the chance of residual cancer in the breast or the body. Although adjuvant therapy lowers the risk of recurrence, it does not necessarily eliminate it.

Along with staging, other sophisticated tools can help determine prognosis and help you and your doctor make decisions about adjuvant therapy. The website Adjuvant! Online (www.adjuvantonline.com) is one such tool that your doctor can access to interpret a variety of prognostic factors. This website should only be used with the interpretation of your doctor. In addition, other tests that can predict the risk of recurrence (such as Oncotype Dx, and Mammaprint; see Diagnosis) may be used to find out whether your doctor recommends adjuvant chemotherapy.

When surgery to remove the cancer is not possible, chemotherapy, radiation therapy, hormone therapy, and/or targeted therapy may be used.

The treatment of recurrent cancer and metastatic cancer depends on how the cancer was first treated and the characteristics of the cancer mentioned above (such as ER, PR, and HER2 status).

Additional descriptions of the most common treatment options for breast cancer are listed below.

Surgery

Surgery is performed to remove the tumor in the breast and to evaluate the surrounding axillary (underarm) lymph nodes. A surgical oncologist is a doctor who specializes in treating cancer using surgery. Generally, the smaller the tumor, the more surgical options a patient has. The types of surgery include the following:

  • A lumpectomy is the removal of the tumor and a small, clear (cancer-free) margin of tissue around the tumor. Most of the breast remains. For both DCIS and invasive cancer, follow-up radiation therapy to the remaining breast tissue is generally recommended. A lumpectomy may also be called breast-conserving surgery, a partial mastectomy, or a segmental mastectomy.

  • A mastectomy is the surgical removal of the entire breast.

Lymph node removal and analysis

Lymph nodes can trap cancer cells traveling away from the original tumor site. It is important to find out whether any of the lymph nodes near the breast contain evidence of cancer.

In an axillary lymph node dissection, the surgeon removes many of the lymph nodes from under the arm, which are then examined by a pathologist for cancer cells. The actual number of nodes removed varies.

Sentinel lymph node biopsy

The sentinel lymph node biopsy procedure allows for the removal of one to a few lymph nodes, reserving a bigger axillary lymph node dissection procedure for patients whose sentinel lymph nodes show evidence of cancer. The smaller lymph node procedure helps patients lower the risk of lymphedema (swelling of the arm) and decreases arm mobility and range-of-motion problems. Learn more about preventing lymphedema after breast cancer treatment.

In this procedure, the surgeon finds and removes the sentinel (first) lymph node (as a practical matter, one to three nodes) that receives drainage from the breast. The pathologist then examines it for cancer cells. To identify the sentinel lymph node, the surgeon injects a dye and/or a radioactive tracer into the area of the cancer and/or around the nipple. The dye or tracer travels to the lymph nodes, arriving at the sentinel node first. The surgeon can find the node when it turns color (if the dye is used) or emits radiation (if the tracer is used).

If the sentinel node is cancer-free, research has shown that there is a good possibility that the subsequent nodes will also be free of cancer and no further surgery of the lymph nodes is performed. If the sentinel lymph node shows cancer is present, then the surgeon will perform an axillary lymph node dissection, removing additional lymph nodes to look for the presence of more cancer. Find out more about ASCO's recommendations for sentinel lymph node biopsy.

Most patients with invasive cancer will undergo either sentinel lymph node biopsy or an axillary lymph node dissection. For those with sentinel nodes that indicate cancer, an axillary lymph node dissection is still considered the standard procedure. If there is obvious evidence of cancer in the lymph nodes before any surgery, then the preferred approach is a full axillary lymph node dissection without a sentinel lymph node biopsy.

Reconstructive (plastic) surgery

Women who undergo a mastectomy may wish to consider breast reconstruction, which is surgery to rebuild the breast. Reconstruction may be done with tissue from another part of the body, or with synthetic implants. A woman may be able to have this done at the same time as a mastectomy (immediate reconstruction) or at some point in the future (delayed reconstruction). In addition, reconstruction may be done after a lumpectomy to improve the look of the breast. Talk with your doctor for more information. Read more about breast reconstruction after a mastectomy, and choosing a breast prosthesis.

Summary

To summarize, surgical treatment options include the following:

  • Removal of cancer in the breast: Lumpectomy (partial mastectomy) almost always followed by radiation therapy or mastectomy, with or without immediate reconstruction

  • Lymph node evaluation: Sentinel lymph node biopsy and/or axillary lymph node dissection

Women are encouraged to talk with their doctors about which surgical option is right for them. More aggressive surgery (such as a mastectomy) is not always better and may result in additional complications. The combination of lumpectomy and radiation therapy has a higher risk of the cancer coming back in the same breast or near the breast, but the long-term survival of women is the same as those who have a mastectomy. Hear from an ASCO expert on mastectomy vs. lumpectomy.

Learn more about cancer surgery.

Radiation therapy

Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The lowest risks of cancer recurrence in the breast after lumpectomy are associated with the use of radiation therapy. Early randomized clinical trials showed, in general, recurrence rates of 30% or more without radiation therapy, compared with 10% recurrence rates with radiation therapy.

After surgery, adjuvant radiation therapy is given regularly for a number of weeks after a lumpectomy to eliminate any remaining cancer cells near the tumor site or elsewhere within the breast. Adjuvant radiation therapy is also recommended for some women after a mastectomy, depending upon the size of their tumor, number of cancerous lymph nodes under the arm, and width of the tissue margin around the tumor removed by the surgeon.

Adjuvant radiation therapy is effective in reducing the chance of breast cancer returning in both the breast and the chest wall. Neoadjuvant radiation therapy is radiation therapy given before surgery to shrink a large tumor, which makes it easier to remove, although this approach is rare.

Radiation therapy can cause side effects, including fatigue, swelling of the breast, and skin changes. A small amount of the lung can be affected by the radiation, although the risk of pneumonitis, or a radiation-related inflammation of the lung tissue, is low. In the past, with older equipment and techniques of radiation therapy, women treated for left-sided breast cancers had a small increase in the long-term risk of heart disease. Modern techniques are now able to spare most of the heart from radiation damage.

Although exposure to radiation is thought to be a risk factor for cancer after many years, less than one in 500 survivors will develop a different kind of cancer other than a breast cancer (usually a type of cancer called sarcoma) within the area that was treated. Clinical trials comparing lumpectomy and adjuvant radiation therapy with mastectomy have not shown a difference in the number of patients developing or dying of other cancers within a 20-year time span.

The most common type of radiation treatment is called external beam radiation therapy, which is radiation therapy given from a machine outside the body. Many types of radiation therapy may be available to you; talk with your doctor about the options, advantages, and disadvantages of these options.

Radiation therapy schedule

Standard radiation therapy after a lumpectomy is external-beam radiation therapy given daily for five days per week (Monday through Friday) for six to seven weeks. This usually includes radiation therapy to the whole breast first for four-and-a-half to five weeks, followed by a more focused treatment to the site of the tumor bed in the breast for the remaining treatments.

This focused part of the treatment, called a boost, is standard for women with invasive breast cancer to reduce the risk of a recurrence in the breast. If there is evidence of cancer in the underarm lymph nodes, radiation therapy may also be given to the lymph node areas in the neck or underarm near the breast or chest wall. Usually, patients who undergo mastectomy do not require radiation therapy. However, for patients with large cancers, many involved lymph nodes, or extension of cancer into the skin or chest wall, radiation may still be recommended after a mastectomy. Standard radiation therapy after a mastectomy is given to the chest wall for five days (Monday through Friday) for five to six weeks.

There has been growing interest in newer radiation regimens (schedules) to shorten the length of treatment from six to seven weeks to periods of three to four weeks. In one method (called hypo-fractionated radiation therapy), a higher daily dose is given to the whole breast each day so that the overall length of treatment is shortened to three to four weeks. This can also be combined with a higher dose given to the tumor bed in the breast either during or after the whole breast radiation treatments. Clinical trials from Canada and the United Kingdom have shown that these shorter schedules can be equally accepted by patients with the same cancer control rates and side effects as longer radiation treatment schedules in patients with node-negative breast cancer. These shorter schedules may become more accepted in the United States and are one way to improve the convenience and time required to complete a course of radiation (see also partial breast irradiation below).

Partial breast irradiation

Partial breast irradiation (PBI) is radiation therapy that is given directly to the tumor area, usually after a lumpectomy, instead of the entire breast, as is routinely done with standard radiation therapy. Targeting the radiation to the tumor area more directly usually shortens the amount of time that patients need to undergo radiation therapy.

When radiation treatment is given using localized radiation delivery methods, it is called brachytherapy. Brachytherapy can involve the implantation of small radioactive pellets, placed in or near the site of the breast tumor, or within plastic catheters placed temporarily in the breast. Mammosite is a type of balloon catheter placed near the breast that delivers radiation therapy. Most types of breast brachytherapy involve short treatment times, ranging from one dose to one week.

Additionally, PBI can be done with standard external-beam radiation therapy that is focused on the area of the tumor bed and not the entire breast. However, only some patients may be eligible for PBI. Although preliminary results have been promising, PBI is still being studied. It is the subject of a large, nationwide clinical trial, and the results proving the safety and effectiveness compared with standard radiation therapy are pending. This trial will help determine which patients and tumors are the best candidates for PBI.

Intensity-modulated radiation therapy

Intensity-modulated radiation therapy (IMRT) is a more advanced way to deliver external-beam radiation therapy to the breast. The intensity of the radiation directed at the breast is varied to target the tumor more precisely, give a uniform distribution of radiation throughout the breast tissue, and avoid damaging healthy tissue more than is possible with traditional radiation treatment. IMRT may reduce the dose to nearby important organs, such as the heart and lung, and reduce the risks of some immediate side effects, such as peeling of the skin during treatment. This can be especially important for women with medium to large breasts who are at greater risk for side effects such as peeling and burns, compared with women with smaller breasts. IMRT also may help to reduce long-term effects on the breast tissue that were common with older radiation techniques such as hardness, swelling, or discoloration.

Adjuvant radiation therapy concerns for older patients and/or those with small tumors

Recent studies have looked at the consequences of using no radiation therapy for women age 70 or older or for those women with a small tumor size. Overall, these studies demonstrate that radiation therapy minimizes the risk of breast cancer recurrence in the same breast, compared with no radiation therapy, but does not affect overall survival. Guidelines from the National Comprehensive Cancer Network (NCCN) continue to recommend radiation therapy as the standard option after lumpectomy. However, they also indicate that women with special personal or tumor characteristics (such being age 70 or older and having other medical conditions that could limit life expectancy within five years, a small tumor, no evidence of cancer in the lymph nodes or surgical margins, and an ER-positive cancer) could reasonably choose not to have radiation therapy and use hormone therapy (see below) alone after lumpectomy, if they are willing to accept a higher risk rate of local recurrence.

Learn more about radiation therapy.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. Most people with breast cancer receive chemotherapy in their doctor's office or outpatient clinic. An adjuvant chemotherapy regimen consists of a specific treatment schedule of drugs given at repeating intervals for a specific number of times.

Chemotherapy may be given intravenously (injected into a vein) or occasionally orally (by mouth), and is usually given in cycles. Chemotherapy may be given before surgery to both shrink a large tumor and reduce the risk of recurrence or adjuvant therapy given after surgery to reduce the risk of recurrence. Chemotherapy is also commonly given at the time of a metastatic breast cancer recurrence. Patients in clinical trials may be offered new drugs or new combinations of existing drugs.

The side effects of chemotherapy depend on the individual and the drug and the dose used, but can include fatigue, hair loss, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished. Rarely, long-term side effects may occur, such as heart damage, nerve damage, or secondary cancers, but studies have shown that these side effects do not shorten a woman’s survival time.

Different drugs are useful for different types of cancer, and research has shown that combinations of certain drugs are sometimes more effective than individual ones. The following drugs or combinations of drugs may be used as adjuvant therapy to treat breast cancer:

  • Cyclophosphamide (Cytoxan)

  • Methotrexate (multiple brand names)

  • Fluorouracil (5-FU, Adrucil)

  • Doxorubicin (Adriamycin)

  • Epirubicin (Ellence)

  • Paclitaxel (Taxol)

  • Docetaxel (Taxotere)

  • CMF (cyclophosphamide, methotrexate, and 5-FU)

  • CAF (cyclophosphamide, doxorubicin, and 5-FU)

  • CEF (cyclophosphamide, epirubicin, and 5-FU)

  • EC (epirubicin and cyclophosphamide)

  • AC (doxorubicin and cyclophosphamide)

  • TAC (docetaxel, doxorubicin, and cyclophosphamide)

  • AC followed by T (doxorubicin and cyclophosphamide, followed by paclitaxel)

  • TC (docetaxel and cyclophosphamide)

Trastuzumab (Herceptin), a HER2 targeted therapy (see below), may also be given with chemotherapy as an adjuvant treatment in HER2-positive breast cancer.

In addition to the drugs and combinations of drugs listed above, the following additional drugs may be used to treat recurrent or metastatic breast cancer, either individually or in combination:

  • Vinorelbine (Navelbine)

  • Capecitabine (Xeloda)

  • Protein bound paclitaxel (Abraxane)

  • Pegylated liposomal doxorubicin (DOXIL, Dox-SL, Evacet, LipoDox)

  • Gemcitabine (Gemzar)

  • Carboplatin (Paraplat, Paraplatin)

  • Cisplatin (Platinol)

  • Ixabepilone (Ixempra)

Trastuzumab and lapatinib (Tykerb) are HER2-targeted therapies that may be given with chemotherapy in HER2-positive metastatic breast cancer. Bevacizumab (Avastin), a blood vessel blocking drug (called anti-angiogenic), is another targeted therapy approved in combination with chemotherapy in the treatment of metastatic breast cancer. (See the Targeted Therapy section below.)

Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions by using searchable drug databases.

Hormone therapy

Hormone therapy helps manage a tumor that tests positive for either estrogen or progesterone receptors in both early-stage and metastatic cancer. This type of tumor uses hormones to fuel its growth. Blocking the hormones usually limits the growth of the tumor.

If it is determined that the tumor is hormone receptor-positive (ER-positive or PR-positive; see Diagnosis), then adjuvant hormone treatment may be used alone or after chemotherapy. Examples of hormone therapy used as adjuvant therapy are tamoxifen, anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin).

Tamoxifen is the drug that researchers have studied the longest for use as a hormone therapy. It blocks estrogen from binding to breast cancer cells. It has been shown to be effective for reducing the risk of recurrence in the treated breast, the risk of developing cancer in the other breast, and the risk of distant recurrence. It is also approved for the chemoprevention of breast cancer in women at high risk for developing the disease and for reducing local recurrence in DCIS. Current research shows that the optimal duration of adjuvant tamoxifen is five years.

Tamoxifen is a pill that is taken daily by mouth. The side effects of tamoxifen include hot flashes, vaginal dryness, discharge or bleeding, a small increased risk of uterine (endometrial) cancer and uterine sarcoma, and an increase in the risk of blood clots. Tamoxifen actually has favorable effects on the bone and cholesterol levels, resulting in less osteoporosis and lower cholesterol levels. Tamoxifen can be effective for both premenopausal and postmenopausal women.

An aromatase inhibitor (AI) decreases the amount of estrogen in postmenopausal women by blocking the aromatase enzyme, which is needed to make estrogen. These drugs include anastrozole, letrozole, and exemestane. All of the AIs are pills taken daily by mouth. The side effects of AIs may include muscle and joint pain, hot flashes, vaginal dryness, an increased risk of osteoporosis and fractures (broken bones), and increases in cholesterol. Clinical trials are evaluating whether women benefit by taking an AI for more than five years. Studies are also evaluating sequences of taking tamoxifen and AIs (taking both together has been shown to be suboptimal). These drugs are not appropriate for women who have not gone through menopause. Learn more about AIs for early breast cancer.

Tamoxifen and the aromatase inhibitors are also commonly used to treat metastatic recurrences. In addition, fulvestrant (Faslodex) is a hormone therapy approved for patients with metastatic cancer. Fulvestrant is in a class called selective
estrogen receptor downregulators (SERDs). Unlike the other oral hormonal therapies used to treat breast cancer, fulvestrant is given monthly by intramuscular injection. Its side effects are due to it being a complete estrogen blocker, and include menopausal symptoms such as hot flashes and vaginal dryness.

Targeted therapy

Targeted therapy is a treatment that targets genes or proteins that contribute to cancer growth and development, or the tissue environment that surrounds the cancer and helps it grow and survive. Currently the two main classes of biologically targeted therapy approved in breast cancer treatment are targeted to the HER2 molecule (HER2 targeted therapy) and the blood vessels in the area of the tumor (anti-angiogenic therapy). Learn more about targeted treatments.

HER2 targeted therapy

  • Trastuzumab is approved for both the treatment of advanced breast cancer and as an adjuvant therapy for early-stage breast cancer for HER2-positive tumors. At this time, one year of trastuzumab is recommended for early-stage breast cancer. In the metastatic setting, the length of treatment is not limited (it is given as long as it is still working). Patients receiving trastuzumab have a small (2% to 5%) risk of heart problems, and this risk is increased if a patient has other risk factors for heart disease. These heart problems do not always go away, but they are usually treatable with medication.

  • Lapatinib is commonly used in women with HER2-positive breast cancer that no longer responds to trastuzumab. The combination of lapatinib and capecitabine is approved for the treatment of women with advanced or metastatic HER2-positive breast cancer who have previously been treated with chemotherapy and trastuzumab.

Anti-angiogenic targeted therapy (blood vessel blocking therapy)

Bevacizumab is used to treat metastatic or recurrent breast cancer (see below). This drug blocks angiogenesis (the formation of new blood vessels), which is needed for tumor growth and metastasis. When combined with paclitaxel, bevacizumab appears to shrink the tumor and keep it smaller for a longer time in women whose breast cancer has spread compared with paclitaxel alone. Recent studies have shown a benefit of adding bevacizumab to other chemotherapy as well.

Anti-osteoclast targeted therapy (drugs that block bone destruction)

  • Bisphosphonates are a class of drugs that block the cells that cause bone destruction (osteoclasts). Bisphosphonates are commonly used in relatively low doses to prevent and treat osteoporosis. In patients with breast cancer that has spread to bone, higher doses of bisphosphonates have been shown to reduce the complications of cancer in the bone, including bone fractures and pain. Pamidronate (Aredia) and zoledronic acid (Zometa) are two intravenous bisphosphonates used to treat breast cancer bone metastasis. Recent studies have suggested that these drugs may also be able to reduce breast cancer recurrences when given in the adjuvant setting, although more data are needed.

  • Denosumab (Prolia) is in another new class of osteoclast-targeted therapies called RANK ligand inhibitors. Although not yet approved for patients with breast cancer, recent studies have shown great promise of these drugs in treating breast cancer bone metastases and osteoporosis.

Learn more about bisphosphonates for breast cancer.

Recurrent and metastatic breast cancer

Breast cancer is called recurrent if the cancer has come back after it was first diagnosed and treated. It may come back in the breast (a local recurrence); in the chest wall (a regional recurrence); or in another part of the body, including distant organs such as the lungs, liver, and bones. A local recurrence is frequently considered curable with further treatment. A metastatic (distant) recurrence is generally considered incurable, but is frequently treatable. Some patients live years after a metastatic recurrence of breast cancer. The goal of treatment for advanced disease is to prolong survival and/or improve quality of life.

Generally, a recurrence is detected when a person has symptoms. These symptoms depend on the site of the recurrence and may include:

  • A lump under the arm or along the chest wall

  • Bone pain or fractures, which may signal bone metastases

  • Headaches or seizures, which may signal brain metastases

  • Chronic coughing or trouble breathing, which may signal lung metastases

  • Abdominal pain or jaundice (yellow skin and eyes), which may be associated with liver metastases

Other symptoms may be related to the location of metastasis and may include changes in vision, changes in energy levels, feeling ill, or extreme fatigue. A biopsy of the recurrent site is often recommended to be certain of the diagnosis and to check for ER, PR, and HER2 status, because this may have changed from the time of the original diagnosis.

The treatment of metastatic or recurrent breast cancer depends on the previous treatment(s), the time since the original diagnosis, and the characteristics of the tumor (such as ER, PR, and HER2 status).

  • For women with a local recurrence within the breast after initial treatment with lumpectomy and adjuvant radiation therapy, the treatment is mastectomy. This usually results in cure.

  • For women with a local or regional recurrence of the chest wall after an initial mastectomy, resection (surgical removal of the recurrence) followed by radiation therapy to the chest wall and lymph nodes is the treatment, unless radiation therapy has already been given (radiation therapy cannot usually be given at full dose to the same area more than once).

  • Total-body therapies such as chemotherapy, hormone therapy and targeted therapies are generally the primary treatment in recurrent metastatic cancer. Radiation therapy and surgery may be used in certain situations for women with a distant metastatic recurrence. Often radiation is used to treat painful bone metastases.

Find out more about common terms used during cancer treatment.

Clinical Trials Resources

Doctors and scientists are always looking for better ways to treat patients with breast cancer. A clinical trial is a way to test a new treatment to prove that it is safe, effective, and possibly better than a standard treatment. The clinical trial may be evaluating a new drug, a new combination of existing treatments, a new approach to radiation therapy or surgery, a new method of treatment or prevention, ways to help patients manage symptoms, or improve a patient’s quality of life. Patients who participate in clinical trials are among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment.

Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that finding new drugs and other therapies is the only way to make progress in treating breast cancer. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with breast cancer.

Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill”. The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials.

To join a clinical trial, patients must participate in a process known as informed consent. During informed consent, the doctor should list all of the patient's options, so that the person understands the standard treatment, and how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find cancer clinical trials.

For specific topics being studied for breast cancer, learn more in the Current Research section.

Side Effects

Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, infection, fatigue, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors and nurses also have many ways to provide relief to patients when such side effects do occur.

Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and the person’s overall health.

Ask your doctor which side effects are most likely to happen (and which are not), which need to be reported right away, when side effects are likely to occur, and how they will be addressed by the health care team if they do happen. Also, be sure to communicate with the doctor and nurses about side effects you experience during and after treatment. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them

In addition to physical side effects, you may experience psychosocial (emotional and social) effects and sexual health concerns. Learn more about the importance of addressing such needs, including concerns about managing the cost of your cancer care.

Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your doctor.

After Treatment

After treatment for breast cancer ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your recovery for the coming months and years. ASCO’s recommendations for breast cancer follow-up care include regular physical examinations and mammograms, among other recommendations. In addition, ASCO offers cancer treatment summaries and a survivorship care plan to help keep track of the breast cancer treatment you received and develop a survivorship care plan once treatment ends. In some instances, patients may be seen at survivorship clinics that specialize in the post-treatment needs of people with cancer.

Breast cancer can come back in the breast or other areas of the body. The symptoms of a cancer recurrence include a new lump in the breast, under the arm, or along the chest wall; bone pain or fractures; headaches or seizures; chronic coughing or trouble breathing; extreme fatigue; and/or feeling ill. Talk with your doctor if you have these or other symptoms. The possibility of recurrence is a common concern among cancer survivors; learn more about coping with fear of recurrence.

After surgery (mastectomy or lumpectomy) to treat breast cancer, the breast may be scarred and may have a different shape or size than before surgery. If lymph nodes were removed as part of the surgery or affected during treatment, lymphedema (swelling of the hand and/or arm) may occur, and this is a life-long risk for patients. Read more about after a mastectomy, preventing lymphedema after breast cancer treatment, breast reconstruction, and choosing a breast prosthesis.

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Some patients experience breathlessness, a dry cough, and/or chest pain two to three months after finishing radiation therapy because the treatment can cause swelling and fibrosis (hardening or thickening) of the lungs. These symptoms are usually temporary. Talk with your doctor if you develop any new symptoms after radiation therapy or if the side effects are not going away.

Patients who received trastuzumab or certain types of chemotherapy called anthracyclines may be at risk of heart problems. Talk with your doctor about the best ways to check for heart problems.

Women taking tamoxifen should have yearly pelvic exams, because this drug can increase the risk of uterine cancer. Tell your doctor or nurse if you notice any abnormal vaginal bleeding or other new symptoms. Women who are taking an aromatase inhibitor, such as anastrozole, exemestane, or letrozole, should have a bone density test before they start treatment and as recommended by their doctor, as these drugs may cause some bone weakness or bone loss.

In addition, women recovering from breast cancer have other symptoms that may persist after treatment. Learn about ways of coping with cancer-related fatigue, a drop in cognitive function (sometimes called "chemobrain"), and other late effects of cancer treatment.

Women recovering from breast cancer are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate physical activity can help rebuild your strength and energy level and may lower the risk of cancer recurrence. Your doctor can help you create a safe exercise plan based upon your needs, physical abilities, and fitness level. Learn more about healthy living after cancer.

Find out more about common terms used after cancer treatment is complete.

Current Research

Research for breast cancer is ongoing. The following advances may still be under investigation in clinical trials and may not be approved or available at this time. Always discuss all diagnostic and treatment options with your doctor.

  • Developing ways to best evaluate the genes and proteins at work in each patent and each breast cancer, to better determine therapeutic approaches (personalized cancer medicine)

  • Testing shorter radiation schedules and more targeted radiation approaches

  • Testing new drug therapies and combinations of therapies

  • Determining who doesn’t need chemotherapy

  • Determining the best ways to give hormone therapies

  • Finding new reconstructive surgery approaches

Find a clinical trial.

Questions to Ask the Doctor

Regular communication with your health care team is important in making informed decisions about your health care. Consider asking the following questions of your doctors:

Questions to ask your entire health care team

Should I see other doctors for a second opinion? Can you give me referrals (names of doctors) to see?

Who is going to help coordinate my treatment and follow-up care?

What can I do to get ready for treatment?

If I’m worried about managing the costs related to my cancer care, who can help me with these concerns? Who can help me understand what aspects of my care are covered by my insurance?

Whom can I call if I have a problem or question about my treatment? Whom do I call if I experience side effects?

Whom can I contact for supportive and emotional help for me? For my family?

Questions to ask your breast surgeon, before your first surgery

Are you board-certified?

Do you specialize in this type of surgery?

How many operations like the one I am considering have you performed?

Do I need any other tests before this surgery?

Am I candidate for a lumpectomy?

Do I need a mastectomy? If so, would you recommend an immediate breast reconstruction (plastic surgery)? What are the advantages and disadvantages to this?

Do the lymph nodes in my underarm be removed?

What is a sentinel lymph node biopsy? What are the benefits and risks? Would you recommend it for me?

What is the risk of lymphedema with a sentinel lymph node biopsy? With axillary lymph node dissection?

Should I consider chemotherapy before surgery?

If have a strong family history of cancer, what is my chance of getting another cancer? How does that change my treatment options?

When do I need to make a decision about surgery?

What should I do to get ready for the operation? Do you have recommendations on how to help me relax before surgery?

What medications and supplements should I stop taking? Should I stop taking hormone replacement therapy? What about birth control pills?

How long will my surgery take?

Will you describe exactly what you will be doing during this operation, and why?

What type of anesthesia will I need for this operation?

Where will the scar be, and what will it look like?

What are the potential risks and side effects of this operation?

What can be done to ease side effects following surgery?

What can I expect regarding the operation?

  • Will I need to be admitted to a hospital for this operation? If so, how long will I stay in the hospital?

  • How long do I have to wait for my preoperative test results? Do I call you, or does your office call me?

  • Will a pathologist examine the tissue and write a report? Who will explain that report to me?

  • What are the possible complications for this type of surgery? How would I know if there is a problem?

  • How long will it take me to recover after the surgery?

  • When can I return to work and other daily activities?

  • Will I have stitches, staples, and/or bandages?

  • Will there be permanent effects from the surgery?

  • Are there instructions or post-operative care pamphlets I can take home with me? When can I shower or bathe?

  • Will I need to have surgical drains? What does this mean? How long will the surgical drains be in?

  • When will I need to return for a follow-up appointment?

  • Will I need help at home after the surgery?

  • What kind of pain will I be in afterwards? Can you help me manage my pain?

Questions to ask your breast surgeon, after your first surgery

What type of breast cancer do I have?

What is the size of the tumor?

What is the grade and stage of this disease? What does this mean?

Can you explain my pathology report (laboratory test results) to me?

Can I get a copy of my pathology report? How and when can I get these results?

Was all of the cancer removed during the surgery?

Has the cancer spread to my lymph nodes or anywhere else in my body?

Do I need additional surgery?

If I have a mastectomy without reconstruction, where can I get a prosthesis?

Will I be able to use my arm after surgery?

When will I be able to work and/or return to my normal routine?

Questions to ask your medical oncologist

What type of breast cancer do I have?

What is the size of my tumor?

What is the grade and stage of this disease? What does this mean?

What is the hormone status of my tumor? What does this mean?

What is my HER2 status? What does this mean?

Do I need other treatment, such as chemotherapy or hormone therapy?

When do I need to make a decision about starting additional treatment?

Do I need more tests to find out if there is cancer anywhere else in my body?

Do you recommend genetic testing and seeing a genetics counselor?

Should I consider my family’s history of breast cancer in making my decision about treatment?

If have a strong family history of cancer, what is my chance of getting another cancer?

What is my prognosis?

What are my options for treatment?

What clinical trials are available to me?

What is chemotherapy? What is hormone (endocrine) therapy? What is targeted therapy?

How will each treatment option benefit me? What are the risks?

What is the expected timeline for each treatment option?

What can I do to get ready for this treatment?

What are the potential side effects of this treatment?

What can be done to ease side effects?

How will this treatment affect my daily life? Will I be able to work, exercise, and perform my usual activities?

What lifestyle changes should I consider making during my treatment?

Do you recommend any nutritional supplements or changes to my diet?

Will I lose my hair?

What clinical trials are open to me?

How does having reached (or not reached) menopause affect my treatment options?

Could this treatment affect my fertility (ability to have children in the future)? Are there other treatments available that do not pose as high a risk to my fertility but are equally effective?

Will attempting to preserve fertility decrease the effectiveness of my cancer treatments (for example, is there a risk of hormones used in this treatment affecting my type of breast cancer, or is there a risk in delaying cancer treatment in order to have this treatment)?

How long should I wait after cancer treatment before trying to have a child?

Can I become pregnant while receiving chemotherapy or radiation therapy? What happens if I become pregnant during treatment? Is there a risk of birth defects and/or harm to the fetus and/or to me?

How will you determine if the cancer has come back after treatment?

After my treatment has ended, what will my follow-up care plan be?

How often will I need to see a doctor?

What tests will I need?

How often will I need those tests?

Can I get copies of my laboratory test results?

Questions to ask your radiation oncologist

What is radiation therapy?

What is the goal of this treatment? Is it to eliminate the cancer?

What are the chances that this treatment will prevent the cancer from coming back?

How often will I receive radiation therapy?

How much time will each treatment take?

Can I bring someone with me to treatment?

Will each treatment be the same? Does the radiation dose or area treated change throughout the period of treatment?

What can I do to get ready for this treatment? Are there recommendations on what clothes to wear or leave behind?

How will this treatment affect my daily life? Will I be able to work, exercise, and perform my usual activities?

Will you describe what I will experience when I receive radiation therapy? Will it hurt or cause me discomfort during the treatment?

What are the potential side effects of this treatment? How can I ease side effects?

How will my skin be affected during radiation therapy? What skin products can I use each day?

Do I need to be concerned about sun exposure?

Should I avoid certain foods, vitamins, or supplements?

Should I avoid using deodorant or antiperspirant during treatment?

What are the possible long-term effects of this treatment?

If I decide to have reconstructive surgery, how would that affect my treatment plan?

Will this treatment affect my fertility?

Are there special services for patients receiving radiation therapy, such as certain parking spaces or parking rates?

Questions to ask your plastic surgeon

Are you board-certified?

Is breast reconstruction your specialty?

How many breast reconstruction surgeries do you perform in a year?

Now that you have examined me, am I a good candidate for reconstruction?

What types of breast reconstruction options do I have?

What are the advantages and disadvantages of each type?

When can I have my reconstruction?

Will I need surgery to the non-reconstructed breast to make the breasts symmetrical?

Will I need to coordinate this with my breast surgeon?

If I have radiation therapy, does that change my options for reconstruction?

What are tissue expanders, and will I need them?

What are the advantages and disadvantages of each?

Which type of implants do you recommend (saline or silicone), and why? What size?

If you use tissue from another part of my body to rebuild my breast(s), where do you recommend it be taken from, and why?

If I have a mastectomy with implant reconstruction, can I also have a nipple reconstruction? If so, when?

What are the costs involved with breast reconstruction? What is covered by my insurance?

How long will the surgery take?

What do I need to do to prepare for the surgery?

What type of anesthesia will I need for this operation?

What can I expect after the operation?

  • How long will I stay in the hospital?

  • What are the possible complications for this type of surgery?

  • How long will it take me to recover?

  • When can I resume my normal activities, including exercise?

  • Will I need to have surgical drains? What does this mean?

  • Will I have stitches, staples, and/or bandages?

  • Will there be a scar or other permanent effects from the surgery?

  • Are there instructions or post-operative care pamphlets I can take home with me?

  • When will I need to return for a follow-up appointment?

What type of results can I expect?

If the reconstruction is on one side only, will it match my other breast’s size and shape?

How will the reconstructed breast feel to the touch?

What type of sensation (feeling) will the reconstructed breast have?

What changes to the reconstructed breast can I expect over time?

Will I need to have surgery again in the future (for example, to replace implants over time)?

What can I expect if my weight changes?

What if I become pregnant in the future?

Questions to ask your fertility specialist

If they are concerned about their ability to have children in the future, young women diagnosed with breast cancer may wish to consult with a fertility specialist, in addition to the doctors listed above, before cancer treatment begins.

How often do you advise people with cancer?

What are my options to preserve my fertility?

What are the costs involved with my options to preserve fertility? What is covered by my insurance?

Learn more about preserving fertility before cancer treatment.

Patient Information Resources

In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease.

View organizations that offer information on this specific type of cancer.