Cohort study of incidence of and risk factors for second primary invasive melanoma in Norway

Patients diagnosed with a primary melanoma are at high risk of subsequent melanomas. Understanding the risk of second primary invasive melanoma and associated factors is crucial to optimize patient follow-up. A cohort study of 19,196 patients aged 18 years or older diagnosed with a first primary melanoma in Norway, found that the incidence rate of a second primary melanoma was highest in the year following diagnosis of the first primary melanoma, decreasing in the second year, and stabilizing thereafter. Older age (≥50 years) and male sex were associated with increased risk and shorter interval before second primary melanoma occurrence. The authors conclude that increased surveillance intensity may be considered in the first 3 years, especially among older men.