Clinical Breast Cancer | 2019
Interdisciplinary Management of Transgender Individuals at Risk for Breast Cancer: Case Reports and Review of the Literature
Abstract
The estimated proportion of transgender adults in the United States has increased from 0.2% in 2007 to 1.8% in 2016. With increasing cultural and social acceptance, more transgender individuals are undergoing genderaffirming treatment. The effect of gender-affirming hormonal treatment on the risk of hormone-dependent malignancies in transgender individuals, including breast cancer, remains largely unexplored. In this report we present 2 cases: a 32-year-old trans woman with a family history of breast cancer and a germline BRCA1, DNA repair associated mutation and a 29-year-old trans man with a family history of male breast cancer who was incidentally diagnosed with ductal carcinoma in situ at the time of chest reconstruction surgery. Gender-affirming hormonal treatment is a lifelong therapeutic regimen. As a result, long-term observational studies are critically needed to assess the lifetime breast cancer risk in transgender individuals. Comprehensive and individually tailored screening programs for transgender individuals are crucial for determining the genetic risk, especially if family history points toward a hereditary predisposition. Future strategies to manage trans women might include gradual reduction of exogenous estrogen doseswith age, thereby simulating naturalmenopause. In trans men, further studies are needed to assess the potential risks of constant testosterone exposure. Aromatase inhibitors could potentially prevent testosterone aromatization to estradiol, but have not yet been systematically studied in this context.