Treatment for pregnant women depends on the stage of the disease and the age of the fetus in months.
Three standard treatments are used:
Surgery
Most pregnant women with breast cancer have surgery to remove the breast. Some lymph nodes under the arm can be removed so that a pathologist can determine under a microscope whether cancer cells are present.
The types of surgery to remove the cancer include:
Modified radical surgery. 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. The tumor and some of the surrounding normal tissue are removed, but the breast itself is not. Some lymph nodes near the axilla may be removed. If the cancer is close to the chest wall, some of the chest wall tissue may also be removed.
After the doctor has removed all the cancer cells that were visible at the time of surgery, some patients may receive chemotherapy or radiation therapy after surgery to kill any remaining cancer cells. For pregnant women with early-stage breast cancer, radiation therapy and hormone therapy are given after the baby is born. The treatment given after surgery to reduce the risk of the cancer coming 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 or stop the growth of cancer cells. There are two types of radiation therapy:
The type of radiation therapy depends on the type and stage of the cancer being treated.
After the baby is born, pregnant women with early-stage (stage I or II) breast cancer may receive external radiation therapy. Patients with advanced (stage III or IV) breast cancer may receive external radiation therapy after the first trimester of pregnancy or, if possible, delayed until after the baby is born.
Chemotherapy
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, both to kill the cancer cells and to stop them from dividing. When chemotherapy is given orally or by injection into a vein or muscle, the drug enters the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is given directly into the cerebrospinal fluid, organs, or body cavities such as the abdomen, the drug mainly affects cancer cells in these areas (regional chemotherapy).
The type of chemotherapy depends on the type and stage of the cancer being treated. Systemic chemotherapy is used for breast cancer in pregnancy.
Chemotherapy is usually not given during the first 3 months of pregnancy. Chemotherapy given after this time is usually not harmful to the fetus, but may result in preterm delivery or low birth weight.
For more information, see Drugs approved for breast cancer.
Ending a pregnancy does not appear to improve the mother’s chances of survival.
Because termination of pregnancy is unlikely to improve the mother’s survival, it is usually not a treatment option.
Treatment for breast cancer may cause side effects.
For information about side effects caused by cancer treatment, see our side effects page.