General Information about Breast Cancer and Pregnancy

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.

Anatomy of the female breast. The nipple and areola are shown on the outside of the breast. The lymph nodes, lobes, lobules, ducts, and other parts of the inside of the breast are also shown.

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.

Possible signs of breast cancer include a lump or change in the breast.

Breast cancer may cause any of the following signs and symptoms. Check with your doctor if any of the following problems occur:

• A lump or thickening in or near the breast or in the underarm area.
• A change in the size or shape of the breast.
• A dimple or puckering in the skin of the breast.
• A nipple turned inward into the breast.
• Fluid, other than breast milk, from the nipple, especially if it's bloody.
• Scaly, red, or swollen skin on the breast, nipple, or areola (the dark area of skin that is around the nipple).
• Dimples in the breast that look like the skin of an orange, called peau d'orange.

Other conditions that are not breast cancer may cause these same symptoms.

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.
  
  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

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.

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.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

• Through tissue. Cancer invades the surrounding normal tissue.
• Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
• Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for breast cancer:

Stage 0 (carcinoma in situ)

There are 2 types of breast carcinoma in situ:

• Ductal carcinoma in situ (DCIS) is a noninvasivecondition in which abnormalcells are found in the lining of a breastduct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive.
• Lobular carcinoma in situ (LCIS) is a condition in which abnormalcells are found in the lobules of the breast. This condition seldom becomes invasive cancer; however, having lobular carcinoma in situ in one breast increases the risk of developing breast cancer in either breast.

Pea, peanut, walnut, and lime show tumor sizes.

Stage I

In stage I, cancer has formed. Stage I is divided into stages IA and IB.

• In stage IA, the tumor is 2 centimeters or smaller and has not spread outside the breast.
• In stage IB, either:
  • no tumor is found in the breast, but small clusters of cancercells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes; or
  • the tumor is 2 centimeters or smaller and small clusters of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes.

Stage II

Stage II is divided into stages IIA and IIB.

• In stage IIA:
  • no tumor is found in the breast, but cancer is found in the axillary lymph nodes (lymph nodes under the arm); or
  • the tumor is 2 centimeters or smaller and has spread to the axillary lymph nodes; or
  • 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:
  • larger than 2 centimeters but not larger than 5 centimeters and has spread to the axillary lymph nodes; or
  • larger than 5 centimeters but has not spread to the axillary lymph nodes.

Stage IIIA

In stage IIIA:

• no tumor is found in the breast. Cancer is found in axillary lymph nodes that are attached to each other or to other structures, or cancer may be found in lymph nodes near the breastbone; or
• the tumor is 2 centimeters or smaller. 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
• the tumor is larger than 2 centimeters but not larger than 5 centimeters. 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
• the tumor is larger than 5 centimeters. Cancer has spread to axillary lymph nodes that may be attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone.

Stage IIIB

In stage IIIB, the tumor may be any size and cancer:

• has spread to the chest wall and/or the skin of the breast; and
• may have spread to axillary lymph nodes that may be attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone.

Cancer that has spread to the skin of the breast is inflammatory breast cancer. See the section on Inflammatory Breast Cancer for more information.

Stage IIIC

In stage IIIC, there may be no sign of cancer 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. Also, 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.

Cancer that has spread to the skin of the breast is inflammatory breast cancer. See the section on Inflammatory Breast Cancer for more information.

Stage IIIC breast cancer is divided into operable and inoperable stage IIIC.

In operable stage IIIC, the cancer:

• is found in ten or more axillary lymph nodes; or
• is found in lymph nodes below the collarbone; or
• is found in axillary lymph nodes and in lymph nodes near the breastbone.

In inoperable stage IIIC breast cancer, the cancer has spread to the lymph nodes above the collarbone.

Stage IV

In stage IV, the cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain.

Inflammatory Breast Cancer

In inflammatory breast cancer, cancer has spread to the skin of the breast and the breast looks red and swollen and feels warm. The redness and warmth occur because the cancercells block the lymph vessels in the skin. The skin of the breast may also show the dimpled appearance called peau d'orange (like the skin of an orange). There may not be any lumps in the breast that can be felt. Inflammatory breast cancer may be stage IIIB, stage IIIC, or stage IV.

Inflammatory breast cancer of the left breast showing peau d'orange and inverted nipple.

Recurrent Breast Cancer

Recurrentbreast cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the breast, in the chest wall, or in other parts of the body.

Treatment Option Overview

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.

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.
  
  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.
  
  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.

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 lower the risk that the cancer will come back, 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 cerebrospinal fluid, 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.

See Drugs Approved for Breast Cancer for more information.

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.

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 is 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.

Because ending the pregnancy is not likely to improve the mother's chance of survival, it is not usually a treatment option.

Treatment Options by Stage

Early Stage Breast Cancer (Stage I and Stage II)

Treatment of early stagebreast 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.

Late Stage Breast Cancer (Stage III and Stage IV)

Treatment of late stagebreast 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

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 cancercells 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
• What You Need to Know About™ Breast Cancer
• Breast Cancer Prevention
• Breast Cancer Screening
• Drugs Approved for Breast Cancer
• Reproductive History and Breast Cancer Risk

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

• What You Need to Know About™ Cancer
• Understanding Cancer Series: Cancer
• Cancer Staging
• Chemotherapy and You: Support for People With Cancer
• Radiation Therapy and You: Support for People With Cancer
• Coping with Cancer: Supportive and Palliative Care
• Cancer Library
• Information For Survivors/Caregivers/Advocates

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Changes to This Summary (07 / 20 / 2011)

The PDQcancer 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.

Editorial changes were made to this summary.

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. 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. 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).

Last Revised: 2011-07-20

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