PREVALENCE OF MELANOCYTIC NEVI AND FRECKLES IN YOUNG ISRAELI MALES - CORRELATION WITH MELANOMA INCIDENCE IN JEWISH MIGRANTS - DEMOGRAPHIC AND HOST FACTORS

The role of host and environmental factors in the pathogenesis of mult iple melanocytic nevi, atypical nevi, and freckles was studied in 1989 in a random sample of 3,040 Israeli males aged 17 years, Multiple mel anocytic nevi were significantly associated with family history of mel anoma or multiple melanocytic nevi (odds ratio (OR) = 15.0), fair or l ightly pigmented skin color (OR = 2.7 and 2.3, respectively), and affi liation to the high or heterogenous melanoma risk group, determined by the incidence rates of melanoma in Jewish migrants from corresponding origin (OR = 3.1 and 2.1, respectively). An environment-related effec t may account for the increased multiple melanocytic nevi risk among s econd- (OR = 8.2) compared with first-generation, native-born recruits (OR = 3.0) from the high melanoma risk group whose families had been living in Israel the longest. Atypical nevi were associated with fair (OR = 6.1) and lightly pigmented (OR = 3.5) skin color, high and moder ate sunburn susceptibility (OR = 4.7 and 2.5, respectively), and famil y history of melanoma or multiple melanocytic nevi (OR = 4.7), Freckle s were significantly associated with sun-sensitive phenotype, family h istory of melanoma or multiple melanocytic nevi (OR = 1.5), Conservati ve (OR = 1.9) or nonreligious status (OR = 1.9), and high (OR = 2.4) o r heterogenous melanoma risk groups (OR = 1.8), These findings indicat e that environmental factors may modify the occurrence of multiple mel anocytic nevi and freckles in genetically susceptible ethnic groups.