Time Trends in Male Breast Cancer Incidence, Mortality, and Survival in Austria (1983-2017)

Male breast cancer (MBC) comprises less than 1% of all breast cancer cases globally and remains understudied with persisting sex-specific survival disadvantages. We aim to contribute to better understanding of MBC with a comprehensive analysis of time-trends over several decades in Austria. We used Austrian National Cancer Registry data on 1648 cases of MBC cases diagnosed between 1983 and 2017 in Austria. Overall incidence, mortality, and survival rates, as well as age-, stage-, and period-specific incidence and survival rates were calculated. Joinpoint regression was performed to assess trends. MBC incidence rates increased throughout the whole observation period (1983-2017) with an annual percent change (APC) of 1.44% (95% confidence interval, CI: 0.77 to 2.11). During the same period, morality rates were stable (APC: -0.25, 95% CI: -0.53 to 0.60). Ten-year survival rates showed three phases of decreasing increases with an average APC of 2.45%, 1983-2009 (95% CI: 2.1 to 2.74). Five-year survival rates improved until 2000 (APC: 2.31, 95% CI: 1.34 to 3.30) and remained stable thereafter (APC: 0.10, 95% CI: -0.61 to 0.80). Stage-specific analyses showed a single trend of stable incidence rates of distant disease MBC (APC: -0.03, 95% CI: -1.67 to 1.65). Further, we observed increases in localised, regional, and unknown stage cancer incidence and increases in incidence rates across all age groups over the whole observation period. However, the estimates on these subgroup-specific trends (according to age- and stage) show wider 95% CIs and lower bounds closer to zero or negative in comparison to our findings on overall incidence, mortality, and survival. Despite improvements in survival rates, MBC mortality rates remained largely stable between 1983 and 2017 in Austria, possibly resulting from a balance between increasing overall incidence and stable incidence rates of distant disease MBC.