SOMATIC DRIVER MUTATIONS IN ORAL AND SINONASAL MUCOSAL MELANOMA. A REFERRAL CENTRE EXPERIENCE IN MEXICO CITY

Abstract

Objective Oral and sinonasal mucosal melanomas (OSNMM) are aggressive tumors with low survival and few therapeutic alternatives. The aim of this study was to describe the prevalence of mutations in NRASQ61K, BRAFV600E, CKITL576P, K642E, MITFE318K and PTENR130;and to analyze the clinic-pathological features present. Findings Cross-sectional and observational study that included cases with OSNMM from the National Cancer Institute of Mexico City and the Oral Pathology Laboratory of UAM-X (January 2000-December 2016). Demographic and clinical data were obtained, and histopathological diagnosis was confirmed. Genomic DNA was obtained and molecular analysis was carried out through quantitative polymerase chain reactions (qPCR) (Customized Biomarker somatic mutation Array®, Qiagen). The statistical analysis was performed using the SPSS v20 software. Forty-eight cases were included, 56.2% were sinonasal melanomas (SNM) and 43.7% oral melanomas (OM). The median age of the individuals was 60 years (Q1-Q3 = 51-74), 54.2% of the cases were men. Higher symptomatology percentages were found among SNM (100% vs. 52.9%, p Conclusions A low prevalence of mutations was found. Somatic driver mutations might not be related with OSNMM development; thus, the current biological agents (vemurafenib and imatinib) may probably be ineffective against OSNMM. It is necessary to continue the search of other molecular alterations to suggest therapeutic alternatives for these tumors, such as: proteins amplification (c-KIT) or epigenetic mechanism which might regulate the genetic expression (miRNAs).