There are special treatment considerations for pregnant women who have breast cancer. Although breast cancer itself does not seem to affect the fetus, certain therapies can be harmful [112]. About 1.5 percent of women diagnosed with breast cancer are pregnant when diagnosed (about 1 in 3,000 pregnancies) [112,113]. Prognosis for pregnant women with breast cancer is similar to that of non-pregnant women, when age and cancer stage are taken into account (for more on cancer stage, see the Diagnosis section). Ending a pregnancy does not seem to affect prognosis [112]. 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. Mammography, including digital mammography, should not be used for routine screening in pregnant women. As a result, most cancers in pregnant women are usually found during a clinical breast exam. Suspicious lumps are tested with other methods, such as ultrasound.
Once breast cancer is diagnosed, mastectomy is most often the recommended treatment for pregnant women who are in their first or second trimester and want to continue their pregnancy. Lumpectomy (also called breast conserving surgery) with radiation is not recommended since radiation can harm the fetus. However, women in their third trimester can have lumpectomy and then wait until after delivery to have radiation therapy. This will not affect their prognosis.
While the anesthesia used during surgery can cross the placenta to the fetus, it has not been shown to result in birth defects or serious pregnancy complications. Breast reconstruction, however, should be delayed until after delivery to avoid further anesthesia and the potential for blood loss [113].
Chemotherapy can sometimes be used during pregnancy, though not without some risk to the fetus. Chemotherapy is not usually given during the first trimester as this is the time when the chances for chemotherapy-related birth defects and miscarriage are greatest [112,113]. During the second and third trimesters, some chemotherapy drugs can be used, but may result in low birth weight and/or premature infants [112]. Women diagnosed in their third trimester most often wait and have chemotherapy after giving birth.
Neither tamoxifen nor other hormone therapies are recommended at any point during pregnancy because of risk to the fetus. Because there are very few data at this time on the use of taxanes and the use of trastuzumab in pregnant women, these drugs should also be avoided [114,115].
For more about surgery, see Surgery.
For more about chemotherapy, see Chemotherapy.
Updated 08/26/09
