MUTATIONAL STATUS AND SOME CLINICO-MORPHOLOGICAL FEATURES OF CUTANEOUS MELANOMA

Cutaneous melanoma is characterized by molecular heterogeneity. The work is devoted to the analysis of mutational status of genes involved in MAPK signaling in primary and metastatic cutaneous melanoma for the detection of tumor sensitivity to the specific targeted therapy as well as possible links of genetic alterations in cutaneous melanoma with some clinical and morphological features. BRAF, NRAS and KIT mutations were found in 60.6%, 13.8% and 1% of cutaneous melanoma cases correspondingly. Mutational status of cutaneous melanoma is differed depending on tumor localization, chronic UV insolation and patients’ age. Thus the rate of the BRAF mutation in melanomas of trunk and extremities (64.7%) was higher than in melanomas of face and head (42.8%). The rate of BRAF mutation was shown to be not associated with pigmentation and tumor growth while NRAS mutation frequency in amelanotic melanoma was lower and in noddle melanoma - higher if compared with pigmented cutaneous melanoma in the radial growth phase. The trend in the association of mutations with melanoma histological type was shown for the first time, the highest rate of BRAF mutation was found in epithelioid melanoma. The obtained results are important for the treatment of cutaneous melanoma as mutational status determines the sensitivity of metastatic melanoma to specific targeted therapy in patients with BRAF, NRAS and KIT mutations.