The Who, What, Where, When and Sometimes, Why.

Breast Cancer Treatment During Pregnancy

How is breast cancer found in pregnant women?

Most breast cancers in pregnant women are found when a woman notices a lump or change in her breast or during a clinical breast exam. Pregnant women may get a clinical breast exam as part of their prenatal care.

Screening mammography isn’t used in pregnant women because the radiation may harm the fetus. And, younger women (under age 40) usually don’t get screening mammography unless they have an increased risk of breast cancer.

Follow-up tests if a change or lump is found

If a lump or other change is found during the first trimester, tests such as breast ultrasound (rather than a mammogram) are used to check for breast cancer.

After the first trimester, a pregnant woman may have a diagnostic mammogram with a shield covering her abdomen to protect the fetus.

Stage at diagnosis

Breast cancer can be hard to detect in pregnant women, women who have just given birth and women who are breastfeeding [186]. The increased size and change in the texture of the breasts can make small cancers hard to feel.

This can delay diagnosis [186]. So, breast cancers in these women may be diagnosed at a more advanced stage than in non-pregnant women [186].

Screening mammography isn’t used in pregnant women because the radiation may harm the fetus. And, younger women (under age 40) usually don’t get screening mammography unless they have an increased risk of breast cancer.

Treatment

There are special treatment concerns for pregnant women who have breast cancer.

Although cancer itself doesn’t seem to affect the fetus, some breast cancer treatments can be harmful [6].

Your treatment plan and the timing of your treatments are chosen to treat your cancer as well as protect the fetus.

Surgery and radiation therapy

Breast surgery is safe during pregnancy.

Although the anesthesia used during surgery can cross the placenta to the fetus, it doesn’t appear to cause birth defects or serious pregnancy problems [187].

Breast reconstruction, however, should be delayed until after the baby is born to avoid further anesthesia and the chance for blood loss.

Radiation therapy is needed after a lumpectomy, but radiation can harm the fetus. So, mastectomy (instead of lumpectomy) is usually recommended for pregnant women who are in their first trimester and want to continue their pregnancy [187].

Some women in their second or third trimester may consider lumpectomy [6]. In these cases, radiation therapy is delayed until after the baby is born. This delay doesn’t affect prognosis [6].

Some women in their second or third trimester may have chemotherapy before surgery (neoadjuvant chemotherapy) [6].

Chemotherapy

Chemotherapy is not given during the first trimester [186-188]. The first trimester is when the chances for drug-related birth defects and miscarriage are greatest [186-188].

During the second and third trimesters, some chemotherapy drugs can be used safely [188].

However, chemotherapy should not be given after week 35 of pregnancy or within 3 weeks of the due date (or planned delivery date) [6]. This gives a woman time to recover from chemotherapy before delivery.

Many women diagnosed in their third trimester wait and have chemotherapy after giving birth.

Hormone therapy and HER2-targeted therapy

Hormone therapies (such as tamoxifen and aromatase inhibitors) and HER2-targeted therapies (such as trastuzumab (Herceptin)) are not used at any point during pregnancy because of risks to the fetus [6,187].

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Gina Samet, survivor & mother

“I was diagnosed with breast cancer and I was 6 months pregnant with my first child. There is hope.”

 

Prognosis

Prognosis for pregnant women with breast cancer is similar to prognosis for non-pregnant women, when age and cancer stage are taken into account [189-190].

Ending a pregnancy doesn’t improve prognosis [189-190].

Breastfeeding after a breast cancer diagnosis

If you’ve been diagnosed with breast cancer and wish to breastfeed, talk with your health care provider.

Breastfeeding should be avoided while being treated with radiation therapy, chemotherapy, hormone therapy or HER2-targeted therapy.

Surgery and radiation therapy may make it difficult to nurse from the treated breast.