Breast Cancer Treatment During Pregnancy

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Treating breast cancer in a pregnant woman requires a lot of consideration for both the health of the patient and the baby.

Here, a breakdown of the different treatments.


Surgery is usually the first treatment option for pregnant women with breast cancer. A lumpectomy or mastectomy and a lymph node removal, all done with anesthesia, may be done to remove the tumor. Because anesthesia can pose some risks to the baby, your doctors will need to work together to determine the best time during your pregnancy to schedule the surgery.

Breast-conserving surgery, such as lumpectomy and partial mastectomy, may require radiation treatment as a follow-up. But that can't be done during pregnancy. Radiation treatments are given in high doses; it can damage a fetus at any stage of a pregnancy, even if a lead shield is used.


During the first three months of your pregnancy, chemotherapy is not given, because it can cause harm to your baby's developing organs. If chemo is needed, it will be given only during the last two trimesters of pregnancy. Many studies on FAC chemotherapy (a combination of fluorouracil, Adriamycin, and cyclophosphamide) have shown that it is safe for your baby. Cases of miscarriage, premature birth, stillbirths, or birth defects attributed to FAC treatment are rare. However, your future fertility will be affected by this kind of chemotherapy.
The drugs used for chemo during pregnancy will depend on the trimester you are in when your treatment begins. Taking certain drugs is riskier during certain trimesters than others.

  • Very risky: Methotrexate — will cause miscarriage and birth defects
  • Controversial: 5-FU (fluorouracil) — some studies have shown it to be harmless, while others note that it can cause miscarriage and birth defects
  • Relatively safe: Cytoxan (cyclophosphamide) — safe if used during the last 6 months of pregnancy; moderate risk if used during first 3 months of pregnancy
  • Safe: Velban (vinblastine) and Adriamycin (doxorubicin) — safe if used during last 6 months of pregnancy
  • Not enough information: Taxol (paclitaxel) and Taxotere (docetaxel) — only a few studies have looked at the effect of taxane chemotherapy on a developing fetus. One researcher reported that treating a pregnant woman with a taxane during her last 3 months of pregnancy resulted in a normal baby arriving at full-term, but more research is needed.

Guard Your Immune System
Chemo lowers your white blood cell count and leaves you and your baby more vulnerable to infection during treatment. Not every baby's immune system will be affected during chemo But if it is compromised and remains low after birth, be sure to get treatment. Doctors feel that it appears safe to provide Neupogen or Neulasta injections during pregnancy to raise the white cell count.

Radiation Therapy After Pregnancy

This therapy is used only after you give birth. It is used to help kill any cancer cells that may still be present in your breast and prevent recurrence. (Radiation harms the baby by causing miscarriage, birth defects, or slow growth.) Not much research has been done on breast radiation or brachytherapy (very localized radiation) and its effect on breasts that have changed as a result of pregnancy, however. Therefore, we don't know if delayed treatment will be as effective after giving birth as it would otherwise. Doctors, in general, agree that radiation for breast cancer is not safe during pregnancy.

Hormonal Therapy After Pregnancy

Tamoxifen is a hormonal therapy that blocks estrogen from breast tissues. It is usually given to women with estrogen-receptor positive breast cancer. However, it is dangerous to take during pregnancy. Hormone therapy can be given after your baby’s birth to lower your risk of recurrence.

Hard Choices

At a time when you may be very focused on the new life within you, you may be asked to make some hard personal decisions. Based on the stage of pregnancy, general health, and diagnosis, you may be asked to consider ending the pregnancy.

Research has not shown that termination has a beneficial effect on breast cancer outcome, and it is not usually considered as a therapeutic option. However, if your cancer is aggressive, was diagnosed late, and you're in need of high-dose chemo and radiation, you might have to discuss termination of your pregnancy in order to allow for proper treatment. Another option could be early delivery of your baby if you are at a late stage of pregnancy and the baby's chance of survival is good.

Talk with your family, oncologist, and obstetrician to fully consider all your options.

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Article Sources
  • American Cancer Society. Pregnancy and Breast Cancer, Breast Cancer Treatment During Pregnancy. Last Updated: 08/08/2007 Breast Cancer Treatment During Pregnancy
  • National Cancer Institute. Breast Cancer and Pregnancy - Health Professional Version. Last Updated: 12/09/2004. Breast Cancer and Pregnancy