Breast Cancer and Pregnancy, Part 2

by National Cancer Institute

(Page 2 of 2)

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. These include the following:

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.

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 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.
• 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.

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 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.

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 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.

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