Surgery
Radiation Therapy
Hormone Therapy
Chemotherapy
Targeted Therapy
Treatment Choices by Stage

Women with breast cancer have many treatment options. The treatment that's best for one woman may not be best for another.

The options are surgery, radiation therapy, hormone therapy, chemotherapy, and targeted therapy. You may receive more than one type of treatment. The treatment options are described below.

Surgery and radiation therapy are types of local therapy. They remove or destroy cancer in the breast.

Hormone therapy, chemotherapy, and targeted therapy are types of systemic therapy. The drug enters the bloodstream and destroys or controls cancer throughout the body.

The treatment that's right for you depends mainly on the stage of the cancer, the results of the hormone receptor tests, the result of the HER2/neu test, and your general health. See Treatment choices by stage ¹.

You may want to talk with your doctor about taking part in a clinical trial, a research study of new treatment methods. Clinical trials are an important option for women at any stage of breast cancer. See Taking Part in Cancer Research ².

Your doctor can describe your treatment choices, the expected results, and the possible side effects. Because cancer therapy often damages healthy cells and tissues, side effects are common. Before treatment starts, ask your health care team about possible side effects, how to prevent or reduce these effects, and how treatment may change your normal activities.

You may want to know how you will look during and after treatment. You and your health care team can work together to develop a treatment plan that meets your medical and personal needs.

Your doctor may refer you to a specialist, or you may ask for a referral. Specialists who treat breast cancer include surgeons, medical oncologists, and radiation oncologists. You also may be referred to a plastic surgeon or reconstructive surgeon. Your health care team may also include an oncology nurse and a registered dietitian.

At any stage of disease, supportive care is available to control pain and other symptoms, to relieve the side effects of treatment, and to ease emotional concerns. Information about such care is available on the NCI Web site at http://www.cancer.gov/cancertopics/coping and from the NCI Cancer Information Service at 1-800-4-CANCER (1-800-422-6237) or at LiveHelp ³ (http://www.cancer.gov/help).

Surgery

Surgery is the most common treatment for breast cancer. (See below for pictures of the types of surgery.) Your doctor can explain each type, discuss and compare the benefits and risks, and describe how each will change the way you look:

• Breast-sparing surgery: This is an operation to remove the cancer but not the breast. It's also called breast-conserving surgery. It can be a lumpectomy or a segmental mastectomy (also called a partial mastectomy). Sometimes an excisional biopsy is the only surgery a woman needs because the surgeon removed the whole lump.
• Mastectomy: This is an operation to remove the entire breast (or as much of the breast tissue as possible). In some cases, a skin-sparing mastectomy may be an option. For this approach, the surgeon removes as little skin as possible.

The surgeon usually removes one or more lymph nodes from under the arm to check for cancer cells. If cancer cells are found in the lymph nodes, other cancer treatments will be needed. (For more about information about lymph node biopsy, see Staging ⁴.)

You may choose to have breast reconstruction. This is plastic surgery to rebuild the shape of the breast. It may be done at the same time as the cancer surgery or later. If you're considering breast reconstruction, you may wish to talk with a plastic surgeon before having cancer surgery. See Breast Reconstruction ⁵.

In breast-sparing surgery, the surgeon removes the cancer in the breast and some normal tissue around it. The surgeon may also remove lymph nodes under the arm. The surgeon sometimes removes some of the lining over the chest muscles below the tumor.

In total (simple) mastectomy, the surgeon removes the whole breast. Some lymph nodes under the arm may also be removed.

In modified radical mastectomy, the surgeon removes the whole breast and most or all of the lymph nodes under the arm. Often, the lining over the chest muscles is removed. A small chest muscle also may be taken out to make it easier to remove the lymph nodes.

The time it takes to heal after surgery is different for each woman. Surgery causes pain and tenderness. Medicine can help control the pain. Before surgery, you should discuss the plan for pain relief with your doctor or nurse. After surgery, your doctor can adjust the plan if you need more relief.

Any kind of surgery also carries a risk of infection, bleeding, or other problems. You should tell your health care team right away if you develop any problems.

You may feel off balance if you've had one or both breasts removed. You may feel more off balance if you have large breasts. This imbalance can cause discomfort in your neck and back.

Also, the skin where your breast was removed may feel tight. Your arm and shoulder muscles may feel stiff and weak. These problems usually go away. The doctor, nurse, or physical therapist can suggest exercises to help you regain movement and strength in your arm and shoulder. Exercise can also reduce stiffness and pain. You may be able to begin gentle exercise within days of surgery.

Because nerves may be injured or cut during surgery, you may have numbness and tingling in your chest, underarm, shoulder, and upper arm. These feelings usually go away within a few weeks or months. But for some women, numbness does not go away.

Removing the lymph nodes under the arm slows the flow of lymph fluid. The fluid may build up in your arm and hand and cause swelling. This swelling is called lymphedema. It can develop soon after surgery or months or even years later. You'll always need to protect the arm and hand on the treated side of your body from cuts, burns, or other injuries. Information about preventing and treating lymphedema is available on the NCI Web site at http://www.cancer.gov/cancertopics/coping and from Information Specialists at 1-800-4-CANCER (1-800-422-6237) or LiveHelp (http://www.cancer.gov/help ³).

Radiation Therapy

Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. It affects cells only in the part of the body that is treated. Radiation therapy may be used after surgery to destroy breast cancer cells that remain in the area.

Doctors use two types of radiation therapy to treat breast cancer. Some women receive both types:

• External radiation therapy: The radiation comes from a large machine outside the body. You will go to a hospital or clinic for treatment. Treatments are usually 5 days a week for 4 to 6 weeks. External radiation is the most common type used for breast cancer.
• Internal radiation therapy (implant radiation therapy or brachytherapy): The doctor places one or more thin tubes inside the breast through a tiny incision. A radioactive substance is loaded into the tube. The treatment session may last for a few minutes, and the substance is removed. When it's removed, no radioactivity remains in your body. Internal radiation therapy may be repeated every day for a week.

Side effects depend mainly on the dose and type of radiation. It's common for the skin in the treated area to become red, dry, tender, and itchy. Your breast may feel heavy and tight. Internal radiation therapy may make your breast look red or bruised. These problems usually go away over time.

Bras and tight clothes may rub your skin and cause soreness. You may want to wear loose-fitting cotton clothes during this time.

Gentle skin care also is important. You should check with your doctor before using any deodorants, lotions, or creams on the treated area. Toward the end of treatment, your skin may become moist and "weepy." Exposing this area to air as much as possible can help the skin heal. After treatment is over, the skin will slowly heal. However, there may be a lasting change in the color of your skin.

You're likely to become very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay active, unless it leads to pain or other problems.

You may wish to discuss with your doctor the possible long-term effects of radiation therapy. For example, radiation therapy to the chest may harm the lung or heart. Also, it can change the size of your breast and the way it looks. If any of these problems occur, your health care team can tell you how to manage them.

You may find it helpful to read the NCI booklet Radiation Therapy and You ⁶.

Hormone Therapy

Hormone therapy may also be called anti-hormone treatment. If lab tests show that the tumor in your breast has hormone receptors, then hormone therapy may be an option. (See Lab Tests with Breast Tissue ⁷.) Hormone therapy keeps cancer cells from getting or using the natural hormones (estrogen and progesterone) they need to grow.

Options before menopause

If you have not gone through menopause, the options include:

• Tamoxifen: This drug can prevent the original breast cancer from returning and also helps prevent the development of new cancers in the other breast. As treatment for metastatic breast cancer, tamoxifen slows or stops the growth of cancer cells that are in the body. It's a pill that you take every day for 5 years.
  
  In general, the side effects of tamoxifen are similar to some of the symptoms of menopause. The most common are hot flashes and vaginal discharge. Others are irregular menstrual periods, thinning bones, headaches, fatigue, nausea, vomiting, vaginal dryness or itching, irritation of the skin around the vagina, and skin rash. Serious side effects are rare, but they include blood clots, strokes, uterine cancer, and cataracts. You may want to read the NCI fact sheet Tamoxifen ⁸.
• LH-RH agonist: This type of drug can prevent the ovaries from making estrogen. The estrogen level falls slowly. Examples are leuprolide and goserelin. This type of drug may be given by injection under the skin in the stomach area. Side effects include hot flashes, headaches, weight gain, thinning bones, and bone pain.
• Surgery to remove your ovaries: Until you go through menopause, your ovaries are your body's main source of estrogen. When the surgeon removes your ovaries, this source of estrogen is also removed. (A woman who has gone through menopause wouldn't benefit from this kind of surgery because her ovaries produce much less estrogen.) When the ovaries are removed, menopause occurs right away. The side effects are often more severe than those caused by natural menopause. Your health care team can suggest ways to cope with these side effects.

Options after menopause

If you have gone through menopause, the options include:

• Aromatase inhibitor: This type of drug prevents the body from making a form of estrogen (estradiol). Examples are anastrazole, exemestane, and letrozole. Common side effects include hot flashes, nausea, vomiting, and painful bones or joints. Serious side effects include thinning bones and an increase in cholesterol.
• Tamoxifen: Hormone therapy is given for at least 5 years. Women who have gone through menopause receive tamoxifen for 2 to 5 years. If tamoxifen is given for less than 5 years, then an aromatase inhibitor often is given to complete the 5 years. Some women have hormone therapy for more than 5 years. See above for more information about tamoxifen and its possible side effects.

Chemotherapy

Chemotherapy uses drugs to kill cancer cells. The drugs that treat breast cancer are usually given through a vein (intravenous) or as a pill. You'll probably receive a combination of drugs.

You may receive chemotherapy in an outpatient part of the hospital, at the doctor's office, or at home. Some women need to stay in the hospital during treatment.

The side effects depend mainly on which drugs are given and how much. Chemotherapy kills fast-growing cancer cells, but the drugs can also harm normal cells that divide rapidly:

• Blood cells: When drugs lower the levels of healthy blood cells, you're more likely to get infections, bruise or bleed easily, and feel very weak and tired. Your health care team will check for low levels of blood cells. If your levels are low, your health care team may stop the chemotherapy for a while or reduce the dose of the drug. There are also medicines that can help your body make new blood cells.
• Cells in hair roots: Chemotherapy may cause hair loss. If you lose your hair, it will grow back after treatment, but the color and texture may be changed.
• Cells that line the digestive tract: Chemotherapy can cause a poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores. Your health care team can give you medicines and suggest other ways to help with these problems.

Some drugs used for breast cancer can cause tingling or numbness in the hands or feet. This problem often goes away after treatment is over.

Other problems may not go away. For example, some of the drugs used for breast cancer may weaken the heart. Your doctor may check your heart before, during, and after treatment. A rare side effect of chemotherapy is that years after treatment, a few women have developed leukemia (cancer of the blood cells).

Some anticancer drugs can damage the ovaries. If you have not gone through menopause yet, you may have hot flashes and vaginal dryness. Your menstrual periods may no longer be regular or may stop. You may become infertile (unable to become pregnant). For women over the age of 35, this damage to the ovaries is likely to be permanent.

On the other hand, you may remain able to become pregnant during chemotherapy. Before treatment begins, you should talk with your doctor about birth control because many drugs given during the first trimester are known to cause birth defects.

You may want to read the NCI booklet Chemotherapy and You ⁹.

Targeted Therapy

Some women with breast cancer may receive drugs called targeted therapy. Targeted therapy uses drugs that block the growth of breast cancer cells. For example, targeted therapy may block the action of an abnormal protein (such as HER2) that stimulates the growth of breast cancer cells. (For information about HER2, see Lab Tests with Breast Tissue ⁷.)

Trastuzumab (Herceptin^®) or lapatinib (TYKERB^®) may be given to a woman whose lab tests show that her breast tumor has too much HER2:

• Trastuzumab: This drug is given through a vein. It may be given alone or with chemotherapy. Side effects that most commonly occur during the first treatment include fever and chills. Other possible side effects include weakness, nausea, vomiting, diarrhea, headaches, difficulty breathing, and rashes. These side effects generally become less severe after the first treatment. Trastuzumab also may cause heart damage, heart failure, and serious breathing problems. Before and during treatment, your doctor will check your heart and lungs. The NCI fact sheet Herceptin® (Trastuzumab) ¹⁰ has more information.
• Lapatinib: The tablet is taken by mouth. Lapatinib is given with chemotherapy. Side effects include nausea, vomiting, diarrhea, tiredness, mouth sores, and rashes. It can also cause red, painful hands and feet. Before treatment, your doctor will check your heart and liver. During treatment, your doctor will watch for signs of heart, lung, or liver problems.

You may want to read the NCI fact sheet Targeted Cancer Therapies ¹¹.

Treatment Choices by Stage

Your treatment options depend on the stage of your disease and these factors:

• The size of the tumor in relation to the size of your breast
• The results of lab tests (such as whether the breast cancer cells need hormones to grow)
• Whether you have gone through menopause
• Your general health

Below are brief descriptions of common treatments for each stage. Other treatments may be appropriate for some women. Research studies (clinical trials) can be an option at all stages of breast cancer. See Taking Part in Cancer Research ².

Stage 0 (DCIS)

Most women with DCIS have breast-sparing surgery followed by radiation therapy. Some women instead choose to have a total mastectomy. Women with DCIS may receive tamoxifen to reduce the risk of developing invasive breast cancer.

Stages I, II, IIIA, and some IIIC

Women with Stage I, II, IIIA, or operable IIIC breast cancer may have a combination of treatments. (Operable means the cancer can be treated with surgery.)

Some may have breast-sparing surgery followed by radiation therapy to the breast. This choice is common for women with Stage I or II breast cancer. Others decide to have a mastectomy.

With either approach, women (especially those with Stage II or IIIA breast cancer) often have lymph nodes under the arm removed.

Whether or not radiation therapy is used after mastectomy depends on the extent of the cancer. If cancer cells are found in 1 to 3 lymph nodes under the arm or if the tumor in the breast is large, the doctor sometimes suggests radiation therapy after mastectomy. If cancer cells are found in more than 3 lymph nodes under the arm, the doctor usually will suggest radiation therapy after mastectomy.

The choice between breast-sparing surgery (followed by radiation therapy) and mastectomy depends on many factors:

• The size, location, and stage of the tumor
• The size of the woman's breast
• Certain features of the cancer
• How the woman feels about how surgery will change her breast
• How the woman feels about radiation therapy
• The woman's ability to travel to a radiation treatment center

You may want to read the NCI booklet Surgery Choices for Women with Early-Stage Breast Cancer ¹².

Some women have chemotherapy before surgery. This is called neoadjuvant therapy (treatment before the main treatment). Chemotherapy before surgery may shrink a large tumor so that breast-sparing surgery is possible. Women with large Stage II or IIIA breast tumors often choose this treatment.

After surgery, many women receive adjuvant therapy. Adjuvant therapy is treatment given after the main treatment to lower the chance of breast cancer returning. Radiation treatment is local therapy that can kill any remaining cancer cells in and near the breast. Women may also have hormone therapy, chemotherapy, targeted therapy, or a combination. These systemic therapies can destroy cancer cells that remain anywhere in the body. They can prevent or delay the cancer from coming back in the breast or elsewhere.

You may want to read the NCI fact sheet Adjuvant and Neoadjuvant Therapy for Breast Cancer ¹³.

Stage IIIB and some Stage IIIC

Women with Stage IIIB (including inflammatory breast cancer) or inoperable Stage IIIC breast cancer have chemotherapy first, and then may be offered other treatments. (Inoperable means the cancer can't be treated with surgery without first shrinking the tumor.) They may also have targeted therapy.

If the chemotherapy or targeted therapy shrinks the tumor, then surgery may be possible:

• Mastectomy: The surgeon removes the breast. In most cases, the lymph nodes under the arm are removed. After surgery, a woman may receive radiation therapy to the chest and underarm area.
• Breast-sparing surgery: In rare cases, the surgeon removes the cancer but not the breast. The lymph nodes under the arm are usually removed. After surgery, a woman may receive radiation therapy to the breast and underarm area.

After surgery, the doctor will likely recommend chemotherapy, targeted therapy, hormone therapy, or a combination. This therapy may help prevent the disease from coming back in the breast or elsewhere.

Stage IV and Recurrent

Women with recurrent breast cancer will be treated based on where the cancer returned. If the cancer returned in the chest area, the doctor may suggest surgery, radiation therapy, chemotherapy, hormone therapy, or a combination.

Women with Stage IV breast cancer or recurrent cancer that has spread to the bones, liver, or other areas usually have hormone therapy, chemotherapy, targeted therapy, or a combination. Radiation therapy may be used to control tumors in certain parts of the body. These treatments are not likely to cure the disease, but they may help a woman live longer.

Many women have supportive care along with anticancer treatments. Anticancer treatments are given to slow the progress of the disease. Supportive care helps manage pain, other symptoms of cancer, or the side effects of treatment (such as nausea). This care can help a woman feel better physically and emotionally. Supportive care does not aim to extend life. Some women with advanced cancer decide to have only supportive care.

Dictionary Terms

Additional cancer treatment given after the primary treatment to lower the risk that the cancer will come back. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, targeted therapy, or biological therapy.

An anticancer drug that is used to decrease estrogen production and suppress the growth of tumors that need estrogen to grow. It is a type of nonsteroidal aromatase inhibitor.

A drug that prevents the formation of estradiol, a female hormone, by interfering with an aromatase enzyme. Aromatase inhibitors are used as a type of hormone therapy for postmenopausal women who have hormone-dependent breast cancer.

A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called implant radiation therapy, internal radiation therapy, and radiation brachytherapy.

An operation to remove the breast cancer but not the breast itself. Types of breast-conserving surgery include lumpectomy (removal of the lump), quadrantectomy (removal of one quarter, or quadrant, of the breast), and segmental mastectomy (removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor). Also called breast-sparing surgery.

An operation to remove the breast cancer but not the breast itself. Types of breast-sparing surgery include lumpectomy (removal of the lump), quadrantectomy (removal of one quarter, or quadrant, of the breast), and segmental mastectomy (removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor). Also called breast-conserving surgery.

Treatment with drugs that kill cancer cells.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

The organs through which food and liquids pass when they are swallowed, digested, and eliminated. These organs are the mouth, esophagus, stomach, small and large intestines, and rectum and anus.

A form of the hormone estrogen.

A drug used to treat advanced breast cancer and to prevent recurrent breast cancer in postmenopausal women who have already been treated with tamoxifen. It is also being studied in the treatment of other types of cancer. Exemestane causes a decrease in the amount of estrogen made by the body. It is a type of aromatase inhibitor. Also called Aromasin.

A type of radiation therapy that uses a machine to aim high-energy rays at the cancer from outside of the body. Also called external-beam radiation therapy.

A drug that belongs to the family of drugs called gonadotropin-releasing hormone analogs. Goserelin is used to block hormone production in the ovaries or testicles.

Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body’s natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called endocrine therapy, hormonal therapy, and hormone treatment.

A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, internal radiation therapy, and radiation brachytherapy.

A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, implant radiation therapy, and radiation brachytherapy.

Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or tube inserted into a vein. Also called IV.

A drug used with another anticancer drug to treat breast cancer that is HER2 positive and has advanced or metastasized (spread to other parts of the body) after treatment with other drugs. Lapatinib is also being studied in the treatment of other types of cancer. It is a type of ErbB-2 and EGFR dual tyrosine kinase inhibitor. Also called GW572016, lapatinib ditosylate, and Tykerb.

A drug used to treat advanced breast cancer in postmenopausal women. Letrozole causes a decrease in the amount of estrogen made by the body. It is a type of aromatase inhibitor. Also called Femara.

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

The active ingredient in a drug used to treat symptoms of advanced prostate cancer. It is also used to treat early puberty in children and certain gynecologic conditions. It is being studied in the treatment of other conditions and types of cancer. Leuprolide blocks the body from making testosterone (a male hormone) and estradiol (a female hormone). It may stop the growth of prostate cancer cells that need testosterone to grow. It is a type of gonadotropin-releasing hormone analog.

A drug that inhibits the secretion of sex hormones. In men, LH-RH agonist causes testosterone levels to fall. In women, LH-RH agonist causes the levels of estrogen and other sex hormones to fall. Also called luteinizing hormone-releasing hormone agonist.

Treatment that affects cells in the tumor and the area close to it.

Surgery to remove abnormal tissue or cancer from the breast and a small amount of normal tissue around it. It is a type of breast-sparing surgery.

A condition in which extra lymph fluid builds up in tissues and causes swelling. It may occur in an arm or leg if lymph vessels are blocked, damaged, or removed by surgery.

Surgery to remove the breast (or as much of the breast tissue as possible).

A doctor who specializes in diagnosing and treating cancer using chemotherapy, hormonal therapy, biological therapy, and targeted therapy. A medical oncologist often is the main health care provider for someone who has cancer. A medical oncologist also gives supportive care and may coordinate treatment given by other specialists.

Surgery for breast cancer in which the breast, most or all of the lymph nodes under the arm, and the lining over the chest muscles are removed. Sometimes the surgeon also removes part of the chest wall muscles.

Treatment given as a first step to shrink a tumor before the main treatment, which is usually surgery, is given. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, and hormone therapy. It is a type of induction therapy.

A nurse who specializes in treating and caring for people who have cancer.

One of a pair of female reproductive glands in which the ova, or eggs, are formed. The ovaries are located in the pelvis, one on each side of the uterus.

The removal of cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually some of the lymph nodes under the arm are also taken out. Also called segmental mastectomy.

A health professional who teaches exercises and physical activities that help condition muscles and restore strength and movement.

A surgeon who specializes in reducing scarring or disfigurement that may occur as a result of accidents, birth defects, or treatment for diseases.

An operation that restores or improves the appearance of body structures.

A doctor who specializes in using radiation to treat cancer.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

A doctor who can surgically reshape or rebuild (reconstruct) a part of the body, such as a woman's breast after surgery for breast cancer.

A health professional with special training in the use of diet and nutrition to keep the body healthy. A registered dietitian may help the medical team improve the nutritional health of a patient.

The removal of cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually some of the lymph nodes under the arm are also taken out. Also called partial mastectomy.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of supportive care is to prevent or treat as early as possible the symptoms of a disease, side effects caused by treatment of a disease, and psychological, social, and spiritual problems related to a disease or its treatment. Also called comfort care, palliative care, and symptom management.

A doctor who removes or repairs a part of the body by operating on the patient.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

Treatment using substances that travel through the bloodstream, reaching and affecting cells all over the body.

A drug used to treat certain types of breast cancer in women and men. It is also used to prevent breast cancer in women who have had ductal carcinoma in situ (abnormal cells in the ducts of the breast) and in women who are at a high risk of developing breast cancer. Tamoxifen is also being studied in the treatment of other types of cancer. It blocks the effects of the hormone estrogen in the breast. Tamoxifen is a type of antiestrogen. Also called tamoxifen citrate.

A type of treatment that uses drugs or other substances, such as monoclonal antibodies, to identify and attack specific cancer cells. Targeted therapy may have fewer side effects than other types of cancer treatments.

Removal of the breast. Also called simple mastectomy.

A monoclonal antibody that binds to HER2 (human epidermal growth factor receptor 2), and can kill HER2-positive cancer cells. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Trastuzumab is used to treat breast cancer that is HER2-positive and has spread after treatment with other drugs. It is also used with other anticancer drugs to treat HER2-positive breast cancer after surgery. Trastuzumab is also being studied in the treatment of other types of cancer. Also called Herceptin.