MELANOMA RISK AND RESIDENCE IN SUNNY AREAS

Melanoma risk among subjects from Germany, France and Belgium who had lived for 1 year or more in sunny climates was examined in a one-to-on e unmatched case-control study conducted among white subjects 20 years old or more. A total of 412 consecutive patients with melanoma diagno sed from 1 January 1991 onwards, were derived from hospital registers; 445 controls were randomly chosen in the same municipality as the cas es. After adjustment for host characteristics, melanoma risk associate d with residence in a sunny area was 2.7 (95% CI: 1.4-5.2), increasing to 4.7 (95% CI: 1.4-13.5) if subjects sought a suntan when residing i n sunny climates, and to 4.3 (95% CI: 1.7-11.1) if subjects arrived be fore the age of 10 years in the sunny area, Residence in sunny areas a nd recreational sun exposure seemed to combine their effects on melano ma risk. Increase in melanoma risk conveyed by deliberate sun exposure during adulthood was highest among subjects who had lived in sunny ar eas as a child or adolescent and lowest among subjects who had never r esided in sunny areas, Our results support conclusions from migrant st udies that indicated that childhood is a critical period of either vul nerability to solar radiation or more frequent exposures to melanoma r isk factors. They also suggest that moderate sun exposure of an adult who was heavily sun exposed in childhood is associated with a higher m elanoma risk than that of high sun exposure of an adult who was sun pr otected in childhood.