RECREATIONAL EXPOSURE TO SUNLIGHT AND LACK OF INFORMATION AS RISK-FACTORS FOR CUTANEOUS MALIGNANT-MELANOMA - RESULTS OF AN -ORGANIZATION-FOR-RESEARCH-AND-TREATMENT-OF-CANCER (EORTC) CASE-CONTROL STUDY IN BELGIUM, FRANCE AND GERMANY

This study addressed the impact of exposure to ultraviolet radiation o n the risk of cutaneous malignant melanoma (CMM), as well as the behav ioural components at stake in its occurrence. We performed a one-to-on e unmatched case-control study among subjects aged 20 years or more wi th naturally non-pigmented skin in Germany, France and Belgium. Four-h undred and twenty consecutive patients with CMM diagnosed from 1 Janua ry 1991 on were derived from hospital registries; 447 controls were ch osen ramdomly in the same municipality as cases. Subjects unaware of t he dangers of exaggerated exposure to sunlight display an estimated CM M risk of 3.72 (95% confidence interval 2.63-5.26). The number of holi day weeks spent annually in sunny resorts and sunbathing during the ho t hours of the day are strong risk factors in the three countries, but not the number of years spent outdoors, as farmers or building worker s. Multiple logistic adjustments on the host characteristics increases the CMM risk associated with recreational exposure to sunlight, as we ll as the adjustment on the unawareness of the dangers of exaggerated exposure to sunlight. Recreational exposure to sunlight and sunburn ea rly in life seem capable of fostering the proliferation of pigmented l esions of the skin. Our data support the hypothesis that most CMM deve lop from pigmented lesions of the skin containing initiated melanocyte s, and that the cell proliferation due to brutal, intermittent exposur es to solar radiation amplifies the likelihood of a melanocyte enterin g into a malignant process. These results reinforce the conviction tha t for controlling the rising incidence of CMM, information about the C MM risk must be widely disseminated, mainly through recommending a pru dent attitude towards exposure to sunlight.