Melanoma risk assessment based on relatives' age at diagnosis

The aim of this study was to determine risk for melanoma among individuals who have a first- or second-degree relative with a history of melanoma, based on the unaffected individual's age and age at diagnosis of the relative.

The study employed a case-control design using a statewide database linked with a Surveillance Epidemiology and End Results cancer registry. A population-based sample of individuals who received at least one diagnosis of first primary, malignant melanoma (n = 14,281), as well as their first- and second-degree relatives, was included. Control individuals with no history of melanoma (n = 70,889) were matched to cases on birth year, gender, race/ethnicity, and county at birth.

Risk for melanoma among relatives of melanoma patients declined with relative's age and age at diagnosis. Individuals between ages 40 and 49 who are first-degree relatives of melanoma patients diagnosed between ages 40 and 49 had the greatest risk for melanoma compared with individuals without a first-degree relative with a melanoma history (HR 4.89; 95% CI 3.11-7.68). Increased melanoma risk among second-degree relatives of patients was typically lower than that for first-degree relatives.

Risk for melanoma, at earlier ages than expected, is increased among relatives of individuals with a history of melanoma, particularly if the melanoma case was diagnosed at a young age. Further research on the relationship between age at diagnosis and relative's melanoma risk could inform melanoma screening recommendations for individuals with a family history of the disease.