Assessment of SOX17 DNA methylation in cell free DNA from patients with operable gastric cancer. Association with prognostic variables and survival

Abstract

DNA methylation represents one of the most common epigenetic changes in human cancer providing important information regarding carcinogenesis. A possible role as a prognostic indicator has also been proposed. The aim of our study was to evaluate the prognostic significance of SOX17 promoter methylation status in patients with operable gastric cancer. Using methylation-specific PCR (MSP) we examined the incidence and prognostic significance of SOX17 methylation status in cell free circulating DNA in the serum of 73 patients with operable gastric cancer. Fifty-one patients were male (69.9%), their median age was 65 years, 43 patients (58.9%) had regional lymph node involvement and all had a Performance Status (WHO) of 0-1. SOX17 promoter was found to be methylated in 43 out of 73 gastric cancer serum samples examined (58.9%). All 20 control serum samples from healthy individuals were negative. Overall survival (OS) was found to be significantly associated with SOX17 methylation (p=0.049). A significant correlation between methylation status and differentiation (p=0.031) was also observed. No other significant associations between different tumor parameters examined and SOX17 methylation status were observed. SOX17 promoter methylation in cell free DNA of patients with operable gastric cancer is a frequent event and may provide important information regarding prognosis in this group of patients.