Screening Mammography for Males With Elevated Breast Cancer Risk, Mutation Carriers, and Gynecomastia.

Introduction: The recommendations for annual mammography for male carriers with gynecomastia are controversial. This study investigated the potential link between gynecomastia and breast cancer in male carriers.

Patients And Methods: The database of a tertiary medical center was retrospectively searched for all male patients who underwent at least 1 digital mammography study from 2016 to 2023. Known carriers of a pathogenic variant in a high-risk breast-cancer gene were identified. Patients were stratified by carrier status, diagnosis of breast cancer, and diagnosis of gynecomastia. Data on demographics, hormone profile, and pathology results were compared.

Results: The cohort included 446 men of whom 82 were known carriers. Gynecomastia was diagnosed by mammography in 251 patients: 239/364 noncarriers (66%) and 12/82 carriers (15%) (P < .0001). Breast cancer was found in 21/364 noncarriers (6%) and 6/82 carriers (7%) (P < .6), and in 10/251 patients with gynecomastia (4%) and 17/193 (9%) without gynecomastia (P < .05). Among patients without gynecomastia, the number of breast cancer cases was similar in carriers and noncarriers (P = .3). Among patients with gynecomastia, the rate of breast cancer was higher in carriers (P < .08). On logistic regression analysis, the effect of gynecomastia on carriers was significant (P = .02). The odds ratio for a breast cancer diagnosis was 5.8 in the presence of gynecomastia (95% CI, 1.1-31, P < .04) and 0.52 in the absence of gynecomastia (95% CI, 0.2-1.7, P < .3).

Conclusion: Gynecomastia may be associated with an increased risk of breast cancer in carriers. Larger studies are needed to determine whether and when to screen male carriers.