Changes in the incidence of cutaneous melanoma in the west of Scotland and Queensland, Australia: hope for health promotion?

Abstract

We compared trends in melanoma incidence by body site in two populations exposed to different levels of sunlight and different approaches to melanoma prevention. We analysed site-specific melanoma incidence during the period 1982-2001 in Queensland, Australia (n=28 862 invasive melanomas; 2536 lentigo maligna melanomas) and the west of Scotland (n=4278 invasive melanomas; 525 lentigo maligna melanomas). Analyses were stratified by sex and age group (<40 years, 40-59 years, >/=60 years). We estimated annual percentage change (APC) in melanoma incidence by regressing the logarithms of the rates and exponentiating the coefficients. Among men, overall melanoma incidence increased log-linearly in both settings, but significantly more rapidly in the west of Scotland (APC 2.8%) than Queensland (APC 1.4%). Rates of increase among Scottish men were higher for every body site and all ages than among Queensland men. Among women, overall melanoma incidence increased more rapidly among Scottish (APC 1.8%) than Queensland women (APC 0.7%). Most discrepant were trends in upper limb melanomas, which underwent large annual increases among Scottish women, but declined among younger Queensland women. Melanoma incidence continues to rise rapidly in all age groups in Scotland and among older people in Queensland. Rates of melanoma in younger people in Queensland are stabilizing, as might be expected if primary prevention campaigns were effective in reducing solar exposure. Variations in rates of change at different body sites warrant further monitoring.