IS THE USE OF SUNSCREENS A RISK FACTOR FOR MALIGNANT-MELANOMA

The relation between use of sunscreens, different host factors and mal ignant melanoma was investigated in a population-based, matched case-c ontrol study of malignant melanoma in the South Swedish Health Care Re gion, which has the highest risk for melanoma in Sweden, between 1 Jul y 1988 and 30 June 1990. In total, 400 melanoma patients and 640 healt hy controls aged 15-75 years answered a comprehensive questionnaire re garding different epidemiologic variables, including questions on use of sunscreens and different constitutional factors. The use of sunscre ens was not found to protect against developing malignant melanoma. In stead, an unexpected relation between the use of sunscreens and the ri sk of developing malignant melanoma was seen (odds ratio (OR) 1.8 for almost always vs never using sunscreens). A tentative dose-response re lation was found. Virtually the same ORs were seen in both sexes. Furt hermore, persons younger than 50 years had a higher OR than persons ol der than 50 years. When different melanoma presentation sites were con sidered, lesions of the trunk were associated with sunscreen use in fe males (adjusted OR = 3.7 for almost always vs never using sunscreens), while lesions of the extremity or head and neck were associated with sunscreen use in males (adjusted OR = 3.2 for almost always vs never u sing sunscreens). Raised naevi on the left arm and freckling were show n to be the major constitutional risk factors (OR = 3.9 for more than three naevi vs none and OR = 1.4, respectively). The results were esse ntially unaltered in a histopathologically re-examined material. Furth er investigations are needed in order to form a basis for melanoma pre vention.