The rates of cutaneous multiple primary melanoma (MPM) vary widely. Researchers sought to determine the incidence of risk factors linked to MPM in an analysis of 16,570 patients with melanoma seen at Kaiser Permanente Northern California.

Investigators compared those with a single melanoma (n=15,488) with those who had MPMs (n=1122). Those in the latter group were older, and most were male, non-Hispanic white, and had a partner.

Subsequent primary melanomas were diagnosed after an average of 3.83 years. They were typically in situ, and thinner than the initial melanoma. Risk of ensuing melanoma decreased from 2% in the first year after diagnosis to 1% through 15 years of follow-up.

Researchers advised being aware of the at-risk subgroups when treating melanoma patients.

Citation: Moore M, Geller A, Warton E, et al. Multiple primary melanomas among 16,570 patients with melanoma diagnosed at Kaiser Permanente Northern California, 1996 to 2011, Capsule Summary. J Am Acad Dermatol. 2015;73(4):630-636.