Coping with Pregnancy-Associated Breast Cancer

For most women, being pregnant is an incredibly uplifting experience. Sure, it comes with its fair share of discomfort and inconvenience, but that is largely outweighed by the incomparable joy of bringing another life into the world.

Unfortunately, there are some health risks associated with pregnancy. One such risk, which affects a relatively small percentage of women, is gestational breast cancer, also known as pregnancy-associated breast cancer (PABC).

Gestational cancer occurs when pregnancy accelerates breast cancer either before the baby is born, during lactation or throughout the first postpartum year. According to the American Cancer Society, breast cancer is found in 1 in 3,000 pregnant women.In fact, up to 20 percent of breast cancer in people under 30 years old is associated with pregnancy.

What Causes Pregnancy-Associated Breast Cancer?

PABC can be the result of hormone changes during pregnancy, when menstrual cycles disappear, and estrogen and progesterone levels rise. These changes can accelerate the growth of cancers associated with BRCA gene mutations or the human epidermal growth factor receptor 2 (HER2).

Diagnosing Gestational Breast Cancer 

Pregnant women and postpartum mothers should continue their regular monthly self-breast exams to feel for lumps or abnormal changes in the breast. If you notice anything out of the ordinary, it is important to see your doctor right away for an in-office exam.

Mammograms may be performed on pregnant women, but only with the use of a special abdominal shield that protects the fetus from radiation. Often, an ultrasound will also be prescribed. Depending on the results, your doctor may also prescribe a biopsy to determine if the lump is cancerous.

Treatments for Breast Cancer During Pregnancy

Once gestational breast cancer is detected, treatment options vary depending on the stage of pregnancy. Your breast oncologist may work closely with your high-risk obstetrician to determine the type and timing of treatment that is both effective at destroying the cancer and safe for the baby.

Radiation therapy is to be avoided throughout pregnancy, as it is not safe for the developing fetus. Chemotherapy should be avoided in the first trimester for the same reason.

During the second and third trimesters, chemotherapy may be prescribed. Some chemotherapy drugs, most notably anthracyclines, have been studied in PABC cases and are considered safe to treat cancer in pregnant women. There is some research has shown that in utero exposure to chemotherapy does not affect fetal development.

If surgery is necessary, it can be individualized based on the risk posed to the fetus from anesthesia, the trimester of pregnancy and the stage of cancer. If the pregnancy is close enough to term (usually at 32 weeks or beyond), the medical team may plan to induce birth. This will allow for the mother’s cancer to be treated more aggressively without additional risk to the baby.

Will My Baby be at Risk Too?

The risk of cancer to an unborn fetus is unknown, although there have been no reported cases of childhood cancers in children exposed to chemotherapy in utero.

However, as a safety precaution, it is recommended that mothers refrain from breastfeeding while receiving chemotherapy to avoid passing chemicals to the baby.

How do Outcomes Vary for Pregnant and Non-Pregnant Women?

Studies have shown that outcomes among pregnant and non-pregnant women with breast cancer are about the same, but the results vary depending on when the cancer was found.

As with all breast cancer, early detection is critical to improving outcomes and ensuring that component in assessing and treating breast cancer—and the same is true during pregnancy.

Pregnancy can be a scary time for both partners in a relationship, and cancer can compound that fear. It’s important to ask questions and seek information and support.