ASSOCIATED FACTORS IN THE PREVALENCE OF MORE THAN 50 COMMON MELANOCYTIC NEVI, ATYPICAL MELANOCYTIC NEVI, AND ACTINIC LENTIGINES - MULTICENTER CASE-CONTROL STUDY OF THE CENTRAL MALIGNANT-MELANOMA REGISTRY OF THE GERMAN-DERMATOLOGICAL-SOCIETY

Several case-control studies identified common and atypical melanocyti c nevi as major risk indicators for the development of cutaneous melan oma. The present investigation was planned to detect factors associate d with the prevalence of these melanoma risk markers. Whole-body exami nation findings and interview data of 513 melanoma patients and 498 ag e- and sex-matched control subjects were analyzed. Existence of more t han 50 common melanocytic nevi and the presence of atypical melanocyti c nevi were significantly related to age and gender, with significantl y elevated relative risk for their prevalence before the age of 60 and in males. Additionally, sunburns before the age of 20 were significan tly associated with both more than 50 common melanocytic nevi (relativ e risk = 1.7) and the presence of atypical melanocytic nevi (relative risk = 1.5). Actinic lentigines were found more frequently with increa sing age, and the presence of actinic lentigines was significantly rel ated to a tendency of freckling in adolescence (relative risk = 2.0) a nd to two or more sunburns after the age of 20 (relative risk = 1.6). In conclusion, sunburns before the age of 20 contribute to the develop ment of multiple melanocytic nevi and atypical melanocytic nevi. In ad ulthood, this type of sun exposure is associated with the development of actinic lentigines. The relative risk of developing cutaneous melan oma increases in association with the development of these benign mela nocytic lesions.