Genotype analysis in Hungarian patients with multiple primary melanoma.

Multiple primary melanoma patients (MPMps) have better prognosis and are more prone to genetic predisposition than single melanoma patients. We aimed to compare genetic background (CDKN2A, CDK4, MITF, MC1R) of 43 Hungarian MPMps with their clinicopathological data. We observed a higher rate of synchronous first and second melanoma (MM) (49%) and a higher frequency of non-melanoma tumor co-occurrence (42%) than reported previously. CDKN2A mutation frequency was 4.7% (E69G, R99P). We identified a new human MC1R variant (D117G) and reported MC1R variant distributions in Hungarian MMs for the first time. The rare R163Q was exceptionally common among Hungarian MPMps, a variant otherwise frequent in Asia, but not in Europe. MC1R 'R' carriers showed histopathological signs of a more progressive disease than 'r' carriers did; however, tumor-infiltrating lymphocytes (TILs) in their second melanomas occurred significantly more frequently. Calculating 5-year overall survival, 'R' carriers showed more unfavourable prognosis (87%) than 'r' carriers did (95%).