Epidemiology and biological characteristics of male breast cancer in Italy

Aim: To evaluate the epidemiology of male breast cancer (MBC) in Italy and to describe incidence and survival data in relation to age, morphology, year of incidence, geographic area, and possible association with other cancers compared with female BC. Methods: Cases were extracted from 40 Italian Cancer Registries. Standardized incidence rates (SIR), age-specific rates, and 5-year survival were calculated. The association with second tumors was also evaluated. All data were compared with data from female BCs. Results: In the 2000–2014 period, 2175 new cases of MBC were registered, with an SIR of 1.7 × 100,000. The incidence showed a slight upward trend and increased with increasing age. The 5-year survival was 82% in the first two periods (2000–2004, 2005–2009), lower than in females (87%). The most frequent morphology was the ductal carcinoma (84%). Stage at diagnosis was 39.5% stage I, 33.1% stage II, 20.9% in stage III, and 6.4% in stage IV. Concerning receptor status, 96.4% had ER+ and 82.5% PR+; 46.5% had high Ki67 and 14.7% HER2 amplified. The risk of BC increased if the man had already had a previous tumor in any site (excess absolute risk, EAR = 2.7) and especially if he had had prostate cancer (EAR = 5.1). Instead, males with a previous diagnosis of BC had an increased risk of testicular, kidney and lung cancer. Conclusions: MBC requires more attention in terms of diagnosis and treatment as clinicians tend to follow the guidelines that have been developed for female BC management.