Distinct Risk Factors Seen for Nevus-Associated, De Novo Melanomas

WEDNESDAY, July 9, 2025 (HealthDay News) -- The risk factor profile is distinct for nevus-associated melanoma (NAM) and de novo melanomas, according to a study published online July 9 in JAMA Dermatology.Catherine M. Olsen, Ph.D., from the QIMR Berghofer Medical Research Institute in Brisbane, Australia, and colleagues examined whether the risk factor profile differs for NAM and de novo invasive melanoma in a population-based prospective cohort study involving participants aged 40 to 69 years at baseline. Data were included for 17,752 men and 21,049 women.The researchers found that 209 participants developed an invasive NAM and 650 developed an invasive de novo melanoma during a median follow-up of 11.4 years. Many of the known phenotypic and sun exposure-related risk factors for melanoma were also associated with NAM and de novo melanoma, but significantly higher hazard ratios were seen for NAM than de novo melanoma for high nevus density and high genetic propensity for melanoma development (hazard ratio for many moles versus no moles, 6.86 versus 3.21; hazard ratio for melanoma polygenic risk score tertile 3 versus tertile 1, 6.46 versus 2.98). For sex, there were no significant differences in the risk factor profile for NAM, but the hazard ratio for older age was significantly higher among men than women with de novo melanoma. The site distribution of NAM varied for men and women, with most common occurrences on the trunk and limbs in men and women, respectively."The current findings are consistent with NAM being associated with the nevus-prone pathway characterized by higher nevus counts, younger age, superficial spreading subtype, and intermittently sun-exposed body sites," the authors write.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter

Distinct Risk Factors Seen for Nevus-Associated, De Novo Melanomas

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