Trends in Skin Cancer Among Older Adults in Iran: A National Registry-Based Study

Background: Skin cancer (SC) is one of the most common cancers in the elderly population, but limited national data exist on the temporal and spatial trends of SC in Iran. This study aimed to estimate the incidence of SC among Iranian people aged ≥ 60 years during 2014–2019.
Methods: Data were obtained from the Iranian National Cancer Registry. Age-specific incidence rates (ASIRs) were calculated per 100,000 population. Normalized age-standardized incidence rates (NASRs) were estimated by direct standardization after renormalizing standard population weights for adults aged ≥60 years. National temporal trends were assessed using multivariable negative binomial regression with population size included as an offset. Province-specific NASR trends were explored using simple linear regression.
Results: There were 51,638 documented SC cases, with 63.6% in males. The overall NASR decreased from 109.82 per 100,000 in 2014 to 104.27 in 2015, increased to 114.64 in 2018, and then decreased to 106.73 in 2019. Age-standardized incidence rates increased with increasing age and peaked at age ≥80 years. The prevalence was higher among males compared to females. Yazd and Isfahan provinces had the highest mean NASRs, and Sistan and Baluchestan and Hormozgan provinces had the lowest mean NASRs. In the adjusted model, the annual increase in incidence was significant, and the province-specific analyses revealed significant temporal differences in nine provinces.
Conclusion: SC incidence among the elderly in Iran differed by age, sex, province, and calendar year during 2014–2019. These findings will help to develop focused prevention efforts, early detection programs, and healthcare aging planning in Iran.