Cutaneous malignant melanoma trends worldwide, 1955-2007

Cutaneous malignant melanoma, the deadliest skin neoplasm, is also the fastest incidence-growing cancer. Melanoma incidence has been increasing worldwide for decades. Increases were mainly observed for early-stage lesions, even if advanced lesions incidence rates are increasing too (but slower). Recent level-offs were observed in high incidence countries, in specifc subpopulations, suggesting future improvements. However, it is necessary to analyse accurate and recent melanoma mortality data to evaluate the real burden of the disease. Does mortality refect incidence worrisome trends? Are these trends similar to other skin cancers? How can we explain melanoma epidemiology tendencies?

In order to answer to those questions, we widely reviewed literature on melanoma epidemiology. Then, we studied mortality trends using the WHO mortality database in 54 countries worldwide, for the longest available time period (up to 53 years). For each country, we computed World age-standardised and age-specifc mortality rates. Then, we conducted Joinpoint analyses, Poisson regression models and cohort analyses. Finally, we made a simpler analysis with NMSC (38 countries) in order to compare CMM and NMSC mortality trends.

About incidence trends, it is still growing in most countries. Regardless, there are levels-offs in high incidence countries. This suggests incidence cannot increase further in those countries. Concerning mortality, we found a clear pattern worldwide. Mortality has been increasing until the 1970s to 1990s. Then, it either levelled-off or decreased. This pattern is likely to be linked with a period effect. To conclude, CMM incidence is increasing whereas mortality is levelling-off, so CMM incidence increases are likely artifcial.