Although nevus count is an established risk factor for melanoma, relationships between nevus number and patient and tumor characteristics have not been well studied and the influence of nevus count on melanoma-specific survival is equivocal. Using data from the Genes, Environment and Melanoma (GEM) study, a large population-based study of primary cutaneous melanoma, we evaluated associations between number of nevi and patient features, including sun-sensitivity summarized in a phenotypic index, and tumor characteristics. We also assessed the association of nevus count with melanoma-specific survival. Higher nevus counts were independently and positively associated with male gender and younger age at diagnosis, and they were inversely associated with lentigo maligna histology. We observed a borderline significant trend of poorer melanoma-specific survival with increasing quartile of nevus count, but little or no association between number of nevi and pigmentary phenotypic characteristics or prognostic tumor features.What's new?
Patients with more than 31 nevi on their backs and arms appear to have the highest risk of developing malignant melanoma. However, it hasn't been clear whether total nevus count is associated with poorer survival once melanoma develops. In this large population-based study, the authors found that, as nevus count increases, so does the risk of melanoma-specific death. However, they found no relationship between number of nevi and histopathological features of melanoma tumors.