Clinicopathological Characteristics of BRAF V600E Mutated Melanomas in the Dalmatian Region of Croatia

Abstract

A high proportion of cutaneous melanomas harbor activating mutations of the BRAF or NRAS genes, which are components of mitogen-activated protein kinase (MAPK) signal transduction pathway. The importance of BRAF V600E mutation in melanoma is not only related to the possibility of the administration of the targeted therapy, but also to the fact that BRAF V600E mutated melanomas have distinct clinicopathological features. We investigated the clinicopathological features of 80 primary skin melanomas with known BRAF V600E mutation status excised in the Dalmatian region of Croatia, with comparison of these features between the mutated and wild-type group. The frequency of BRAF V600E mutation was 47.5%. In comparison with wild-type melanomas, BRAF V600E mutated melanomas were significantly associated with younger age and female sex (P=0.014 and P=0.011, respectively). The mutated melanomas were more often located on the extremities, of a nodular type, ulcerated, and with higher median of mitotic index but without significant difference in comparison with wild-type tumors. There were no differences in the depth of invasion and the presence of lymphovascular invasion, tumor infiltrating lymphocytes, and regression between the investigated groups. The frequency of BRAF V600E mutation in our cohort of primary skin melanomas and the clinicopathological features of mutated tumors were similar to those reported in the literature, except for the higher proportion of women observed in our group with mutation.