Frequency of mutations in BRAF, NRAS, and KIT in different populations and histological subtypes of melanoma: a systemic review.

The presence of mutations of BRAF, NRAS, and KIT genes is recognized as playing a role during carcinogenesis. Our study aims to evaluate and review other studies that present the frequency of mutations of BRAF, NRAS, and KIT genes for different populations, and analyse correlation to their clinical-pathological characteristics and to the demographics of melanoma. Thirty-two articles were selected from a collection of published literature studying 6299 patients. The parameters for correlation to different variables were calculated by odds ratio, for random and single effects. 38.5% of patients present BRAF gene mutations, 16.4% in NRAS, and 10% in KIT. Mutations of the BRAF gene were correlated to superficial spreading melanoma (odds ratio = 1.31), localization in the torso (odds ratio = 1.42) and presence of metastases. Mutations in NRAS were correlated to nodular melanoma (odds ratio = 1.57), localized in the limbs (odds ratio = 1.31). Mutations of the KIT gene were correlated to mucosal melanoma (odds ratio = 1.59). Populations in Brazil, the US, Sweden, Italian, and Australia were found to be correlated to mutations of BRAF and melanoma. Populations in Italy, Sweden, Spain, and the US were found to be correlated to mutations of NRAS. Populations in Japan, China, Turkey, Canada, and Russia were found to be correlated to mutations of KIT. Data correlated to the presence of melanoma and population type is due to the amount of studies performed across of globe.