Delivery of a healthy infant in a woman with breast cancer inadvertently treated with exemestane and goserelin during pregnancy: A case report.

Exemestane and goserelin combination therapy is a well-established adjuvant treatment for hormone receptor-positive breast cancer. Both medications are contraindicated during pregnancy as their safety in the pregnant population is not yet established. We report a rare case of a 40-year-old multigravida with T1N0M0 breast cancer, receiving exemestane and goserelin post bilateral mastectomy. Despite over four years of amenorrhoea on goserelin, she conceived unexpectedly, and inadvertently continued both medications until she discovered she was pregnant at 13 weeks' gestation. The pregnancy was uncomplicated. A healthy female infant was delivered via caesarean section at 40 weeks. The notable features of this case are inadvertent pregnancy despite induction of amenorrhoea, and no evidence of congenital fetal anomaly despite exposure to exemestane and goserelin until 13 weeks' gestation. Women of child-bearing age receiving adjuvant endocrine therapy for breast cancer should be counselled to use effective contraception to minimise risk of harmful effects in pregnancy.