As women in the US delay childbearing, it has been hypothesized that the incidence of breast cancer diagnosed during pregnancy will increase. There are very little prospective data on the treatment of pregnant women with breast cancer with chemotherapy and even less data on the outcomes of their children who were exposed to chemotherapy in utero.

Fifty-seven pregnant breast cancer patients were treated on a single-arm, multidisciplinary, institutional review board-approved protocol with FAC (5-fluorouracil, doxorubicin, cyclophosphamide) in the adjuvant (n = 32) or neoadjuvant (n = 25) setting. Parents/guardians were surveyed by mail or telephone regarding outcomes of children exposed to chemotherapy in utero.

Of the 57 women, 40 are alive and disease-free, 3 have recurrent breast cancer, 12 died from breast cancer, 1 died from other causes, and 1 was lost to follow-up. Of the 25 patients who received neoadjuvant FAC, 6 had a pathologic complete response, whereas 4 had no tumor response to chemotherapy and eventually died from their disease. All women who delivered had live births. One child has Down syndrome and 2 have congenital anomalies (club foot; congenital bilateral ureteral reflux). The children are healthy and those in school are doing well, although 2 have special educational needs.

Breast cancer can be treated with FAC chemotherapy during the second and third trimesters without significant short-term complications for the majority of children exposed to chemotherapy in utero. Longer follow-up of the children is needed to evaluate possible late side effects such as impaired cardiac function and fertility.