ORLANDO – The more , according to a review of over 200,000 subjects in decades-long health professional cohorts.
It’s well known that nevi increase the risk of melanoma, and the study confirmed that fact. The basal cell carcinoma finding, however, is novel. “The relationship between nevi and non-melanoma skin cancer has not [previously] been clearly demonstrated in large population cohorts,” said lead investigator Erin X. Wei, MD, a dermatologist at Brigham and Women’s Hospital, Boston.
“Nevus count serves as a convenient maker to identify patients at risk for both melanoma and basal cell carcinoma. Providers should be aware of these increased risks in patients with any nevi on the extremity, particularly 15 or more,” she said at the International Investigative Dermatology meeting.
There was no association, meanwhile, between nevus counts and squamous cell carcinoma (SCC).
The team reviewed 176,317 women in the Nurses’ Health Study 1 and 2, as well as 32,383 men in the Health Professionals Follow-up Study. Subjects were enrolled in the 1980s and followed through 2012. They reported nevus counts on their arms or legs at baseline, and filled out questionnaires on a regular basis that, among many other things, asked about new skin cancer diagnoses.
Overall, there were 30,457 incident basal cell carcinomas (BCCs), 1,704 incident melanomas, and 2,296 incident SCCs. Melanomas and SCCs – as well as a portion of BCCs – were confirmed by histology.
The team correlated the skin cancer incidence with how many moles subjects reported at baseline: zero, 1-5, 6-14, or 15 or more.