Breast Cancer in Transgender Patients Following Medical and Surgical Intervention.

BACKGROUND

Current breast cancer (BCa) screening guidance does not adequately address transgender populations despite differences in hormone exposure and post-surgical anatomy.

MATERIALS AND

METHODS

Using the TriNetX network (2003-2023), transgender adults were identified using ICD-10 codes and grouped by sex assigned at birth and intervention: no intervention (NI), hormone therapy (HT ≥ 1 year), or HT with surgery (SX). BCa was defined as ≥ 2 diagnoses of malignant breast neoplasm (ICD-10 C50.x).

RESULTS

Among 33,775 transgender women, 12 (0.036%) developed BCa. HT alone was not associated with increased odds of BCa diagnosis. Among 44,117 transgender men, 37 (0.084%) developed BCa. Combined HT and chest surgery was associated with higher odds of BCa diagnosis compared with NI. Older age at diagnosis and Black race were significant predictors in both cohorts.

CONCLUSIONS

HT alone was not associated with increased breast cancer risk in transgender individuals. However, residual breast tissue after chest surgery may contribute to persistent risk in transgender men, supporting individualized screening strategies based on intervention type, age, and race.