About 1.5 percent of women with breast cancer are pregnant when diagnosed (about 1 in 3,000 pregnancies) [145].
There are special treatment concerns for pregnant women who have breast cancer. Although cancer itself does not seem to affect the fetus, certain treatments for breast cancer can be harmful [145].
Diagnosis of breast cancer in pregnant women
Cancer is often diagnosed at a more advanced stage in pregnant women than in non-pregnant women. The increased size and change in texture of the breasts during pregnancy can make smaller cancers harder to detect.
Screening mammography (including digital mammography) should not be used in pregnant women. Thus, most cancers in pregnant women are found during a clinical breast exam.
When a suspicious lump is found during the first trimester, tests such as ultrasound (rather than mammography) are used to check the lump for cancer. After the first trimester, a pregnant woman may have a diagnostic mammogram with a shield covering her abdomen to protect the fetus.
Breast cancer treatment for pregnant women
Surgery and radiation therapy
Mastectomy is usually recommended for pregnant women who are in their first trimester and want to continue their pregnancy [66]. Women in their second or third trimester may consider lumpectomy (also called breast conserving surgery) [66]. However, radiation therapy is needed with lumpectomy and radiation can harm the fetus. So, women who have a lumpectomy will wait and have radiation therapy after the baby is born. This delay does not worsen the prognosis [66].
Although the anesthesia used during surgery can cross the placenta to the fetus, it does not appear to cause birth defects or serious pregnancy complications [146]. Breast reconstruction, however, should be delayed until after the baby is born to avoid further anesthesia and the chance of blood loss.
Learn more about surgery.
Learn more about radiation therapy.
Chemotherapy, hormone therapy and targeted therapy
Chemotherapy is not usually given during the first trimester as this is the time when the chances for drug-related birth defects and miscarriage are greatest [145-146]. During the second and third trimesters, some chemotherapy drugs can be used safely [66]. Many women diagnosed in their third trimester often wait and have chemotherapy after giving birth.
Hormone therapies (tamoxifen and aromatase inhibitors) are not used at any point during pregnancy because of risk to the fetus [66,146]. At this time, there are too few data on the use of taxanes and trastuzumab in pregnant women, so these drugs should also be avoided [66,146-147].
Learn more about chemotherapy.
Learn more about hormone therapy.
Learn more about trastuzumab.
Prognosis for pregnant women with breast cancer
Prognosis for pregnant women with breast cancer is similar to that of non-pregnant women, when age and cancer stage are taken into account (more on cancer stage). Ending a pregnancy does not improve prognosis [145].
Breastfeeding after a breast cancer diagnosis
If you are diagnosed with breast cancer during your pregnancy and wish to breastfeed after your child is born, talk to your health care provider. For most women, breastfeeding should be avoided while being treated with radiation therapy, chemotherapy, hormone therapy or targeted therapy.
Updated 05/20/11
