Non-melanoma skin cancer burden in Spain: a nationwide analysis of incidence trends (1990-2019)

Background: : Non-melanoma skin cancer (NMSC) is the most common skin cancer in Spain, yet national data on its incidence trends are limited. Objectives: : To analyse the trends in NMSC incidence in Spain from 1990 to 2019, examining variations by sex, age, period, and birth cohort. Materials & Methods: : Data on NMSC incidence was sourced from the Global Health Data Exchange. Age- standardized incidence rates (ASIRs) were calculated using the direct method. Trends and average annual percentage changes were identified using Joinpoint regression analysis. Age-period-cohort analysis was applied to assess age-specific, period-specific, and cohort-specific relative risks. Results: : From 1990 to 2019, Spain reported 2,302,399 NMSC cases. ASIRs significantly declined post-2005, with men exhibiting slightly higher rates than women. Joinpoint analysis revealed distinct trends between genders, with men experiencing an initial rise followed by a decline, while women exhibited periods of increase interspersed with decline. APC analysis showed a net decrease in age-adjusted NMSC rates for both sexes. Local drift analysis showed a downward trend in most age groups, indicating a broad decrease at the population level. However, no decrease was observed in young men (20-24 years). Both sexes showed an increased risk of NMSC between 1990 and 2002, followed by a decrease. In particular, those born at the beginning of the 21st st century showed a significant decrease in NMSC risk compared with earlier cohorts, suggesting a possible cohort effect. Conclusion: : A comprehensive analysis of NMSC trends in Spain highlights the need for ongoing research and interventions to address the evolving burden.