Breast Cancer and Pregnancy

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.

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: A test that uses sound waves to create images of areas inside the body. High-energy sound waves are bounced off internal tissues and organs. The echoes are changed into pictures called sonograms. The doctor can identify tumors by looking at the sonogram. Mammogram: A special x-ray of the breast that may find tumors that are too small to feel. A mammogram can be performed with little risk to the fetus. Mammograms in pregnant women may appear negative even though cancer is present. Biopsy: The removal of cells, tissues, or fluid to view under a microscope and check for signs of disease.

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

The treatment options and prognosis (chance of recovery) depend on the stage of the cancer (whether it is in the breast only or has spread to other places in the body), the tumor size, the type of breast cancer, the age of the fetus, whether there are symptoms, and the patient's general health.

Survival rates of pregnant women with breast cancer may be lower than for women who are not pregnant.

Pregnant women with breast cancer may be less likely to survive because the diagnosis of their cancer is often delayed and the cancers are more advanced when they are found. Cancers found at later stages are more difficult to treat successfully.

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 the best treatment. (Refer to the PDQ summary on Breast Cancer Treatment 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

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. Before starting treatment, patients may want to think about taking part in a clinical trial. 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.

Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Cancer.gov Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

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 patients with breast cancer have surgery to remove the cancer from 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.

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

Lumpectomy: Removal of the tumor and a small amount of normal tissue around it. Lumpectomy is usually followed by radiation therapy to the breast. Most doctors also take out some of the lymph nodes under the arm. Partial or segmental mastectomy: Removal of the cancer, some of the breast tissue around the tumor, and the lining over the chest muscles below the tumor. Some of the lymph nodes under the arm are usually taken out. In most cases, partial mastectomy is followed by radiation therapy.

Other types of surgery include the following:
Total or simple mastectomy: Removal of the whole breast. Sometimes lymph nodes under the arm are also taken out.
Modified radical mastectomy: Removal of the breast, many of the lymph nodes under the arm, the lining over the chest muscles, and sometimes, part of the chest wall muscles.


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 the use of x-rays or other types of radiation to kill cancer cells and shrink tumors. Radiation therapy may use external radiation (using a machine outside the body) or internal radiation. Internal radiation involves putting radioisotopes (materials that produce radiation) through thin plastic tubes into the area where cancer cells are found. Radiation may be used after surgery in addition to chemotherapy, and hormone therapy. Breast cancer is treated with external radiation.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be taken by mouth, or it may be put into the body by inserting a needle into a vein or muscle. Either type of chemotherapy is called systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells throughout the body.

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.

Other types of treatment are being tested in clinical trials. These include the following:

Hormone therapy

Hormones are chemicals produced by glands in the body and are circulated in the bloodstream. Estrogen and progesterone are hormones that affect the way some cancers grow. If tests show that the cancer cells have estrogen and progesterone receptors (molecules found in some cancer cells to which estrogen and progesterone will attach), hormone therapy is used to block the way these hormones help the cancer grow. This may be done by using drugs that block the way hormones work or by surgically removing organs that make hormones, such as the ovaries.

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

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Cancer.gov Web site.

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. 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.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Cancer.gov Web site.

Late Stage Breast Cancer (Stage III and Stage IV)

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


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 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

Call

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.

Web sites and Organizations

The NCI's Cancer.gov Web site 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. There are also many other places where people can get materials and information about cancer treatment and services. Local hospitals may have information on local and regional agencies that offer information about finances, getting to and from treatment, receiving care at home, and dealing with problems associated with cancer treatment.

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. 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.

Write

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