Promoter methylation profile of surgical margins from patients with oral squamous cell carcinoma

Abstract

Head and neck cancer is the sixth most common cancer worldwide. Oral squamous cell carcinoma it the most frequent, followed by the larynx and pharynx. The presence of microscopic tumor in surgical margins contributes to increased local recurrence rate and decreased overall survival. From 10 to 30% of patients with negative histological margins will present locoregional recurrences. Many studies have suggested the presence of genetic and molecular changes prior to the onset cancer phenotype in the adjacent mucosa of the primary tumor. Increased methylation in the promoter region of a tumor suppressor gene may lead to the progressive reduction of its expression, resulting in its silencing and the selection of cells with proliferative advantage. This study aimed to evaluate the hypermethylation profile of surgical margins from patient's oral squamous cell carcinoma as a prognostic factor for tumor recurrence. An initial methyloma screening using the Illumina Infinium MethylationEPIC (850K) BeadChip platform was performed in 32 histologically negative surgical margins samples for the selection of candidate genes. A subsequent validation based on the bioinformatics analysis will be carried out by an additional 75 margin samples, from formalin fixed paraffin embedded tissues. Up to 10 differentially methylated targets will be analyzed by pyrosequencing. Statistical analysis will be conducted on SPSS 23.0 software.