Breast cancer and pregnancy: how safe is trastuzumab?

BACKGROUND

A 29-year-old woman was diagnosed with lymph-node-positive, steroid-hormone-receptor-negative and HER2/neu-positive breast cancer. She underwent surgery followed by cyclophosphamide, epirubicin, and 5-fluorouracil chemotherapy, and received radiotherapy followed by trastuzumab therapy for 1 year. During the tenth month of trastuzumab therapy, the patient reported a missed period and had a positive pregnancy test.

INVESTIGATIONS: Physical examination, pregnancy test, echocardiography.

DIAGNOSIS: Unintended pregnancy during adjuvant trastuzumab therapy.

MANAGEMENT: Cessation of trastuzumab and close monitoring of mother and fetus during pregnancy.