DYSPLASTIC NEVI AS A MELANOMA RISK FACTOR IN PATIENTS WITH FAMILIAL MELANOMA

Background. Familial melanoma has been associated with ''clinically at ypical moles'' or ''dysplastic nevi,'' (DN) which are markers for incr eased melanoma risk. In addition, melanomas in these kindreds present at a younger age, and tend to be multiple. Methods. Melanoma incidence rates were determined for 710 members of 311 melanoma families, defin ed as kindreds in which melanoma had occurred in two or more blood rel atives. Patients were classified either clinically or histologically a s expressing DN. Melanomas that occurred before the first examination were recorded, and patients were followed prospectively for new melano mas. Results. In prospective follow-up, the age-adjusted melanoma inci dence rate was 1710/100,000 patient-years in family members with DN. I n contrast, the rate was zero (no melanomas occurred) in family member s without DN. For family members with DN, but without a history of mel anoma, the age-adjusted incidence rate of melanoma was 413/100,000 pat ient-years, whereas the rate was 2779/100,000 patient-years in family members with DN and a history of melanoma. Conclusions. Dysplastic nev i and a history of melanoma are strong risk factors for subsequent mel anoma. Prognostic factors are greatly improved for patients with melan omas diagnosed in follow-up compared with the first two melanomas in e ach kindred. These findings warrant surveillance of individuals with D N who are members of familial melanoma kindreds.