International patterns and trends in the incidence of melanoma and cutaneous squamous cell carcinoma, 1989–2020.

This article focuses on comparing incidence trends of cutaneous squamous cell carcinoma (cSCC) and melanoma across seven mid-to-high latitude populations—Finland, Norway, Sweden, Denmark, Scotland, the Netherlands, and Tasmania (Australia)—to understand changing patterns of ultraviolet radiation (UVR) exposure. The study found that the ratio of cSCC-to-melanoma incidence increases with proximity to the equator and over time, with cSCC incidence now exceeding melanoma incidence in both men and women in all populations studied. Melanoma incidence was higher among younger individuals, while cSCC incidence was higher among older individuals, reflecting their differing associations with intermittent versus cumulative sun exposure. Additionally, the incidence of cSCC has increased more rapidly in women than men in most countries, suggesting changes in UVR exposure behaviors. Despite international efforts to reduce UVB radiation through ozone layer protection, skin cancer incidence, particularly cSCC, continues to rise, highlighting the need for ongoing prevention strategies.