Breast cancer in transgender women: A case report

The risk of breast cancer in transgender women continues to be a topic of debate in the medical literature. Studies have theorized an increased risk in transgender women taking feminizing hormone therapy on the basis of established risk factors and histological characteristics in cisgender men and established increased risk in cisgender women on hormone replacement therapy. Historically, testing this theory has been challenging due to a relative lack of cases and large-scale, long-term studies reported in the literature. Studies to date have been contradictory, and a lack of medical consensus has led to inconsistencies in establishing universally accepted standards of care, including guidelines for screening. We hope to contribute to the ongoing discussion by presenting a case report of a transgender woman who had taken feminizing hormone therapy intermittently over 40 years and was subsequently diagnosed with breast cancer. •The risk of breast cancer in transgender women remains uncertain.•Growing evidence suggests feminizing hormone therapy increases breast cancer risk.•There is a lack of consensus on breast cancer screening for transgender women.•Further research is needed to inform treatment and screening guidelines.