Mole study challenges melanoma thinking

Most people with melanoma have few moles and no atypical moles, Harvard researchers have found.

The relationship between mole patterns, tumour thickness and cancer prognosis is complex, say the researchers, writing in JAMA Dermatology.

Their study, which contradicts previous literature, included 566 patients with melanoma. Most (376) had zero to 20 total naevi, while about three quarters (415 patients) had no atypical naevi.

In patients younger than 60, having more than 50 naevi was associated with reduced risk for thick melanoma, while having more than five atypical naevi compared with no atypical naevi was