Sunscreen use and malignant melanoma.

In a new population-based, matched, case-control study from southern Sweden of 571 patients with a first diagnosis of cutaneous malignant melanoma, between 1995 and 1997, and 913 healthy controls aged 16 to 80 years, the association between sunscreen use and malignant melanoma was evaluated. The median sun protection factor (SPF) used by both cases and controls was 6, range 2 to 25. Sunscreen users reported greater sun exposure than non-users. Persons who used sunscreens did not have a decreased risk of malignant melanoma. Instead, a significantly elevated odds ratio (OR) for developing malignant melanoma after regular sunscreen use was found, adjusted for history of sunburns, hair color, frequency of sunbathing during the summer, and duration of each sunbathing occasion ¿OR = 1.8, 95% confidence interval (CI) 1.1-2.9]. The OR was higher in subjects who reported that sunscreen use enabled them to spend more time sunbathing (adjusted OR = 8.7, 95% CI 1.0-75.8 for always vs. never use). The association appeared to hold for subjects who did not suffer from sunburns while using sunscreens, for subjects who used SPF of 10 or lower, and among men. The pattern of a significantly increased melanoma risk was seen only for lesions of the trunk. Our results are probably related mainly to earlier sunscreens of low SPF. They substantiate the hypothesis that sunscreen use, by permitting more time sunbathing, is associated with melanoma occurrence. Copyright 2000 Wiley-Liss, Inc.