General Information about Breast Cancer and Pregnancy
Stages of Breast Cancer
Treatment Option Overview
Treatment Options by Stage

Early Stage Breast Cancer (Stage I and Stage II) Late Stage Breast Cancer (Stage III and Stage IV)

Other Considerations for Pregnancy and Breast Cancer
To Learn More About Breast Cancer and Pregnancy
Get More Information From NCI
Changes to This Summary (06/13/2008)
About PDQ

General Information about Breast Cancer and Pregnancy

Key Points for This Section

Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast. Breast cancer is sometimes detected (found) in women who are pregnant or have just given birth. It may be difficult to detect (find) breast cancer early in pregnant or nursing women, whose breasts are often tender and swollen. Breast examination should be part of prenatal and postnatal care. Tests that examine the breasts are used to detect (find) and diagnose breast cancer. Certain factors affect prognosis (chance of recovery) and treatment options.

Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.

The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. The lobes and lobules are connected by thin tubes called ducts.

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Anatomy of the breast, showing lymph nodes and lymph vessels.

Each breast also contains blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. The lymph vessels lead to small, bean-shaped organs called lymph nodes that help the body fight infection and disease. Lymph nodes are found throughout the body. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.

Breast cancer is sometimes detected (found) in women who are pregnant or have just given birth.

In women who are pregnant or who have just given birth, breast cancer occurs most often between the ages of 32 and 38. Breast cancer occurs about once in every 3,000 pregnancies.

It may be difficult to detect (find) breast cancer early in pregnant or nursing women, whose breasts are often tender and swollen.

Women who are pregnant, nursing, or have just given birth usually have tender, swollen breasts. This can make small lumps difficult to detect and may lead to delays in diagnosing breast cancer. Because of these delays, cancers are often found at a later stage in these women.

Breast examination should be part of prenatal and postnatal care.

To detect breast cancer, pregnant and nursing women should examine their breasts themselves. Women should also receive clinical breast examinations during their routine prenatal and postnatal examinations.

Tests that examine the breasts are used to detect (find) and diagnose breast cancer.

If an abnormality is found, one or all of the following tests may be used:

• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
• Mammogram: An x-ray of the breast. A mammogram can be performed with little risk to the fetus. Mammograms in pregnant women may appear negative even though cancer is present.

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  Mammography of the right breast.

• Biopsy: The removal of cells or tissues by a pathologist so they can be viewed under a microscope to check for signs of cancer.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

• The stage of the cancer (whether it is in the breast only or has spread to other places in the body).
• The size of the tumor.
• The type of breast cancer.
• The age of the fetus.
• Whether there are symptoms.
• The patient’s general health.

Stages of Breast Cancer

Key Points for This Section

After breast cancer has been diagnosed, tests are done to find out if cancer cells have spread within the breast or to other parts of the body. Methods used to stage breast cancer can be changed to make them safer for the fetus.

After breast cancer has been diagnosed, tests are done to find out if cancer cells have spread within the breast or to other parts of the body.

The process used to find out if the cancer has spread within the breast or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. (Refer to the PDQ summary on Breast Cancer Treatment ¹ for more information on the stages used for breast cancer.)

Methods used to stage breast cancer can be changed to make them safer for the fetus.

Standard methods for giving imaging scans can be adjusted so that the fetus is exposed to less radiation. Tests to measure the level of hormones in the blood may also be used in the staging process.

Treatment Option Overview

Key Points for This Section

There are different types of treatment for patients with breast cancer. Treatment options for pregnant women depend on the stage of the disease and the age of the fetus. Three types of standard treatment are used: Surgery Radiation therapy Chemotherapy New types of treatment are being tested in clinical trials. Hormone therapy Ending the pregnancy does not seem to improve the mother’s chance of survival and is not usually a treatment option.

There are different types of treatment for patients with breast cancer.

Different types of treatment are available for patients with breast cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

For some patients, taking part in a clinical trial may be the best treatment choice. Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. Information about clinical trials is available from the NCI Web site ².

Treatment options for pregnant women depend on the stage of the disease and the age of the fetus.

Three types of standard treatment are used:

Surgery

Most pregnant women with breast cancer have surgery to remove the breast. Some of the lymph nodes under the arm are usually taken out and looked at under a microscope to see if they contain cancer cells.

Types of surgery to remove the breast include:

• Simple mastectomy: A surgical procedure to remove the whole breast that contains cancer. Some of the lymph nodes under the arm may also be removed for biopsy. This procedure is also called a total mastectomy.

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  Total (simple) mastectomy. The dotted line shows where the entire breast is removed. Some lymph nodes under the arm may also be removed.

• Modified radical mastectomy: A surgical procedure to remove the whole breast that has cancer, many of the lymph nodes under the arm, the lining over the chest muscles, and sometimes, part of the chest wall muscles.

  Enlarge

  Modified radical mastectomy. The dotted line shows where the entire breast and some lymph nodes are removed. Part of the chest wall muscle may also be removed.

Breast-conserving surgery, an operation to remove the cancer but not the breast itself, includes the following:

• Lumpectomy: A surgical procedure to remove a tumor (lump) and a small amount of normal tissue around it. Most doctors also take out some of the lymph nodes under the arm.
• Partial mastectomy: A surgical procedure to remove the part of the breast that contains cancer and some normal tissue around it. Some of the lymph nodes under the arm may also be removed for biopsy. This procedure is also called a segmental mastectomy.

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Breast-conserving surgery. Dotted lines show the area containing the tumor that is removed and some of the lymph nodes that may be removed.

Even if the doctor removes all of the cancer that can be seen at the time of surgery, the patient may be given radiation therapy, chemotherapy, or hormone therapy after surgery to try to kill any cancer cells that may be left. Treatment given after surgery to increase the chances of a cure is called adjuvant therapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Radiation therapy should not be given to pregnant women with early stage (stage I or II) breast cancer because it can harm the fetus. For women with late stage (stage III or IV) breast cancer, it should not be given during the first 3 months of pregnancy.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Chemotherapy should not be given during the first 3 months of pregnancy. Chemotherapy given after this time does not usually harm the fetus but may cause early labor and low birth weight.

New types of treatment are being tested in clinical trials.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site ².

Hormone therapy

Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. Some hormones can cause certain cancers to grow. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy are used to reduce the production of hormones or block them from working.

The effectiveness of hormone therapy, alone or combined with chemotherapy, in treating breast cancer in pregnant women is not yet known.

Ending the pregnancy does not seem to improve the mother’s chance of survival and is not usually a treatment option.

If the cancer must be treated with chemotherapy and radiation therapy, which may harm the fetus, ending the pregnancy is sometimes considered. This decision may depend on the stage of cancer, the age of the fetus, and the mother’s chance of survival.

Treatment Options by Stage

Early Stage Breast Cancer (Stage I and Stage II)

Treatment of early stage breast cancer (stage I and stage II) may be surgery followed by adjuvant therapy as follows:

• Modified radical mastectomy.
• Breast-conserving surgery: Lumpectomy, partial mastectomy or segmental mastectomy.
• Breast-conserving surgery during pregnancy followed by radiation therapy after the baby is born.
• Surgery during pregnancy followed by chemotherapy after the first 3 months of pregnancy.
• Clinical trials of surgery followed by hormone therapy with or without chemotherapy.

Treatment of late stage breast cancer (stage III and stage IV) may include the following:

• Radiation therapy.
• Chemotherapy.

Radiation therapy and chemotherapy should not be given during the first 3 months of pregnancy.

Other Considerations for Pregnancy and Breast Cancer

Key Points for This Section

Lactation (breast milk production) and breast-feeding should be stopped if surgery or chemotherapy is planned. Breast cancer does not appear to harm the fetus. Pregnancy does not seem to affect the survival of women who have had breast cancer in the past. Effects of certain cancer treatments on later pregnancies are not known.

Lactation (breast milk production) and breast-feeding should be stopped if surgery or chemotherapy is planned.

If surgery is planned, breast-feeding should be stopped to reduce blood flow in the breasts and make them smaller. Breast-feeding should also be stopped if chemotherapy is planned. Many anticancer drugs, especially cyclophosphamide and methotrexate, may occur in high levels in breast milk and may harm the nursing baby. Women receiving chemotherapy should not breast-feed. Stopping lactation does not improve survival of the mother.

Breast cancer does not appear to harm the fetus.

Breast cancer cells do not seem to pass from the mother to the fetus.

Pregnancy does not seem to affect the survival of women who have had breast cancer in the past.

Some doctors recommend that a woman wait 2 years after treatment for breast cancer before trying to have a baby, so that any early return of the cancer would be detected. This may affect a woman’s decision to become pregnant. The fetus does not seem to be affected if the mother has previously had breast cancer.

Effects of certain cancer treatments on later pregnancies are not known.

The effects of treatment with high-dose chemotherapy and a bone marrow transplant, with or without radiation therapy, on later pregnancies are not known.

To Learn More About Breast Cancer and Pregnancy

For more information from the National Cancer Institute about breast cancer and pregnancy, see the following:

• Breast Cancer Home Page ³
• What You Need to Know About™ Breast Cancer ⁴
• Breast Cancer Prevention ⁵
• Breast Cancer Screening ⁶
• Surgery Choices for Women with Early-Stage Breast Cancer ⁷
• Pregnancy and Breast Cancer Risk ⁸

For general cancer information and other resources from the National Cancer Institute, see the following:

• What You Need to Know About™ Cancer - An Overview ⁹
• Understanding Cancer Series: Cancer ¹⁰
• Staging: Questions and Answers ¹¹
• Chemotherapy and You: Support for People With Cancer ¹²
• Radiation Therapy and You: Support for People With Cancer ¹³
• Coping with Cancer ¹⁴
• Support and Resources ¹⁵
• Cancer Library ¹⁶
• Information For Survivors/Caregivers/Advocates ¹⁷

Get More Information From NCI

Call 1-800-4-CANCER

For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. The call is free and a trained Cancer Information Specialist is available to answer your questions.

Chat online

The NCI's LiveHelp® ¹⁸ online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 9:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.

Write to us

For more information from the NCI, please write to this address:

NCI Public Inquiries Office

Suite 3036A

6116 Executive Boulevard, MSC8322

Bethesda, MD 20892-8322

Search the NCI Web site

The NCI Web site ¹⁹ provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our “Best Bets” search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator ²⁰. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.

Changes to This Summary (06/13/2008)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Several enhancements have been made to this summary to better explain certain medical concepts and to give readers more information about clinical trials. The following changes were made:

• Information about patients taking part in clinical trials was added to the Treatment Option Overview ²¹ section.
• A new section called “ To Learn More ²² ” was added. It includes links to more information about this type of cancer and about cancer in general.
• The “Get More Information from NCI” section (originally called “To Learn More”) was revised.

About PDQ

PDQ is a comprehensive cancer database available on NCI's Web site.

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site ¹⁹. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.

PDQ contains cancer information summaries.

The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.

The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.

Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.

PDQ also contains information on clinical trials.

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site ²³. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.

Glossary Terms

The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.

Not normal. An abnormal lesion or growth may be cancerous, premalignant (likely to become cancer), or benign.

Treatment given after the primary treatment to increase the chances of a cure. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, or biological therapy.

The underarm or armpit.

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

A procedure to replace bone marrow that has been destroyed by treatment with high doses of anticancer drugs or radiation. Transplantation may be autologous (an individual's own marrow saved before treatment), allogeneic (marrow donated by someone else), or syngeneic (marrow donated by an identical twin).

Glandular organ located on the chest. The breast is made up of connective tissue, fat, and breast tissue that contains the glands that can make milk. Also called mammary gland.

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

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.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

A flexible tube used to deliver fluids into or withdraw fluids from the body.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Treatment with drugs that kill cancer cells.

The muscles, bones, and joints that make up the area of the body between the neck and the abdomen.

An exam of the breast performed by a health care provider to check for lumps or other changes.

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 a clinical study.

An anticancer drug that belongs to the family of drugs called alkylating agents.

The process of identifying a disease, such as cancer, from its signs and symptoms.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

In medicine, a tube or vessel of the body through which fluids pass.

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.

The developing offspring from 7 to 8 weeks after conception until birth.

Liquid.

An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk. Endocrine glands release the substances directly into the bloodstream. Exocrine glands release the substances into a duct or opening to the inside or outside of the body.

An intensive drug treatment to kill cancer cells, but that also destroys the bone marrow and can cause other severe side effects. High-dose chemotherapy is usually followed by bone marrow or stem cell transplantation to rebuild the bone marrow.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

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 hormonal therapy, hormone treatment, or endocrine therapy.

A method of producing pictures of areas inside the body.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

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, radiation brachytherapy, and implant radiation therapy.

A portion of an organ, such as the liver, lung, breast, thyroid, or brain.

A small lobe or a subdivision of a lobe.

Surgery to remove the tumor and a small amount of normal tissue around it.

The clear fluid that travels through the lymphatic system and carries cells that help fight infections and other diseases. Also called lymphatic fluid.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.

An x-ray of the breast.

A drug used to treat some types of cancer, severe skin conditions such as psoriasis, and rheumatoid arthritis. Methotrexate stops cells from making DNA. It is a type of antimetabolite. Also called amethopterin and Rheumatrex.

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.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

A test result that fails to show the specific disease or condition for which the test is being done.

A part of the body that performs a specific function. For example, the heart is an organ.

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 doctor who identifies diseases by studying cells and tissues under a microscope.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

The likely outcome or course of a disease; the chance of recovery or recurrence.

Energy released in the form of particle or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, medical x-rays, and energy given off by a radioisotope (unstable form of a chemical element that releases radiation as it breaks down and becomes more stable).

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 radiotherapy and irradiation.

Giving off radiation.

A small, radioactive pellet that is placed in or near a tumor. Cancer cells are killed by the energy given off as the radioactive material breaks down and becomes more stable.

A molecule inside or on the surface of a cell that binds to a specific substance and causes a specific physiologic effect in the cell.

To come back or to return.

Treatment with anticancer drugs directed to a specific area of the body.

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.

Removal of the breast. Also called total mastectomy.

A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called an ultrasonogram.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

The tumor is 2 centimeters or smaller and has not spread outside the breast.

Stage II is divided into stages IIA and IIB. In stage IIA, (1) no tumor is found in the breast, but cancer is found in the axillary lymph nodes (the lymph nodes under the arm); or (2) the tumor is 2 centimeters or smaller and has spread to the axillary lymph nodes; or (3) the tumor is larger than 2 centimeters but not larger than 5 centimeters and has not spread to the axillary lymph nodes. In stage IIB, the tumor is either (1) larger than 2 centimeters but not larger than 5 centimeters and has spread to the axillary lymph nodes; or (2) larger than 5 centimeters but has not spread to the axillary lymph nodes.

Stage III breast cancer is divided into stages IIIA, IIIB, and IIIC. In stage IIIA, (1) no tumor is found in the breast, but cancer is found in axillary (under the arm) lymph nodes that are attached to each other or to other structures, or cancer may be found in lymph nodes near the breastbone; or (2) the tumor is 2 centimeters or smaller and cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or the cancer may have spread to lymph nodes near the breastbone; or (3) the tumor is larger than 2 centimeters but not larger than 5 centimeters and cancer has spread to axillary lymph nodes that are attached to each other or to other structures or cancer may have spread to lymph nodes near the breastbone; or (4) the tumor is larger than 5 centimeters and cancer has spread to axillary lymph nodes that may be attached to each other or to other structures or the cancer may have spread to lymph nodes near the breastbone. In stage IIIB, the tumor may be any size and cancer (1) has spread to the chest wall and/or the skin of the breast; and (2) may have spread to axillary lymph nodes that may be attached to each other or to other structures or the cancer may have spread to lymph nodes near the breastbone. In stage IIIC, no tumor is found in the breast or the tumor may be any size and may have spread to the chest wall and/or the skin of the breast. Cancer has spread to lymph nodes above or below the collarbone and may have spread to axillary lymph nodes or to lymph nodes near the breastbone. In operable stage IIIC, the cancer (1) is found in ten or more axillary lymph nodes; or (2) is found in the lymph nodes below the collarbone; or (3) is found in axillary lymph nodes and in lymph nodes near the breastbone. In inoperable stage IIIC, the cancer has spread to the lymph nodes above the collarbone.

Cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain.

Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.

In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called standard of care or best practice.

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

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Treatment with anticancer drugs that travel through the blood to cells all over the body.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasonography.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.