Trends in male breast cancer in Spain, 1999-2023: a nationwide analysis of incidence and mortality.

BACKGROUND

Male breast cancer (MBC) is rare and increasing globally, with limited data on trends in Spain. The study examines MBC trends, incidence, and mortality over a 25 year period (1999-2023) to guide public health strategies.

METHODS

An ecological trend study was conducted using national mortality data from the Spanish National Statistics Institute and modeled incidence estimates from the Global Burden of Disease Study 2023. Age-standardized incidence and mortality rates (ASIR and ASMR) per 100,000 men were calculated using the European Standard Population 2013. Joinpoint regression identified temporal inflection points. Age-Period-Cohort (APC) modeling quantified age, period, and cohort effects for men aged 30-84 years.

RESULTS

The study recorded 7594 MBC cases and 1,931 deaths. ASMR declined from 0.65 to 0.39 per 100,000 (AAPC - 1.8%), with significant declines from 1999-2006 (APC - 5.1%) and 2013-2023 (APC - 3.6%). ASIR remained largely stable (AAPC 0.1%), increasing slightly from 1999-2006 (APC + 1.7%) and declining thereafter (APC - 0.5%). The Mortality-to-Incidence Ratio decreased from 0.41 to 0.26. APC analysis demonstrated significant net declines in mortality (- 1.33%/year) and incidence (- 0.83%/year), primarily driven by period effects and lower risk among later birth cohorts. Mortality reductions were most pronounced among men aged 55-64 years.

CONCLUSION

MBC mortality in Spain has declined steadily, reflecting improvements in clinical management, while stable incidence indicates minimal change in disease occurrence. Continued focus on early detection, male-specific awareness, and adherence to guideline-based therapy is essential to further reduce the MBC burden.