Invasive Breast Cancer in a Trans Man After Bilateral Mastectomy: Case Report and Literature Review
Camille Kopetti, Clara Schaffer, Khalil Zaman, Aikaterini Liapi, Pietro G. di Summa, Olivier Bauquis
Abstract
Clinical Practice Points•Prophylactic mastectomy reduces the incidence and mortality of breast cancer (BCa) by more than 90% in cis women.•The incidence of BCa reported overall in trans men is similar to the incidence in cis men and is far below the incidence of 154 per 100,000 in cis women.•In trans men, testosterone therapy combined with mastectomy could diminish the risk of BCa and could explain the low incidence of BCa. However, it needs to be considered that a bilateral “mastectomy” in trans men is actually not an oncologic procedure, and is often closer to a breast “reduction” with remaining breast tissue.•Five cases of BCa after bilateral mastectomy and testosterone therapy have been reported.•The role of cross-sex hormones in the development of BCa is debated in the literature.•Cases of BCa in trans men might be underreported in the literature.•Trans men without mastectomy should follow screening guidelines for cis women as they remain at risk for BCa.•We emphasise the need to systematically collect data in the transgender population to understand better the impact of cross-sex hormone therapy in the development of BCa, identify patients at risk of BCa, and ultimately define more evidence-based screening and treatment guidelines. •Prophylactic mastectomy reduces the incidence and mortality of breast cancer (BCa) by more than 90% in cis women.•The incidence of BCa reported overall in trans men is similar to the incidence in cis men and is far below the incidence of 154 per 100,000 in cis women.•In trans men, testosterone therapy combined with mastectomy could diminish the risk of BCa and could explain the low incidence of BCa. However, it needs to be considered that a bilateral “mastectomy” in trans men is actually not an oncologic procedure, and is often closer to a breast “reduction” with remaining breast tissue.•Five cases of BCa after bilateral mastectomy and testosterone therapy have been reported.•The role of cross-sex hormones in the development of BCa is debated in the literature.•Cases of BCa in trans men might be underreported in the literature.•Trans men without mastectomy should follow screening guidelines for cis women as they remain at risk for BCa.•We emphasise the need to systematically collect data in the transgender population to understand better the impact of cross-sex hormone therapy in the development of BCa, identify patients at risk of BCa, and ultimately define more evidence-based screening and treatment guidelines.