5-year cumulative survival of oral cancer patients with FAS and FASL SNPs

Abstract

IntroductionFAS binds to FASL to initiate extrinsic apoptosis which plays a key role in maintaining cellular homeostasis. Disruption of apoptosis leads to tumorigenesis. MethodsWe investigated the association of FAS -1377 G/A, FAS -670 A/G and FASL -844 T/C SNPs with survival of oral cancer (OC) patients, stratified by gender and cancer sub-type into buccal mucosa cancer (BMC) and tongue cancer (TC). 5-year cumulative survival and hazards ratio (HR) with respect to risk and clinical factors were estimated using Kaplan–Meier analysis and Cox proportional hazards models. ResultsThe survival of the patients differed amongst both genders in TC and BMC. Survival depended on risk and clinical factors. Male TC patients with FAS -1377 ‘GA’ survived significantly (P = 0.038) better than BMC patients, with mean survival time of 45.24 ± 2.93 months. TC females with metastasis and FAS -670 ‘AA’ or ‘AG’ had longer survival than TC males. BMC males with FASL -844 ‘TC’ (25.11 ± 6.71 months) or ‘CC’ (22.63 ± 3.57 months) and with PNS showed better survival than wild type ‘TT’ (7.9 ± 1.27 months). FAS -1377 ‘AA’ (HR = 47.14) and FASL -844 ‘CC’ variant (HR = 10.87) showed significantly increased risk of death (HR) in TC males, when LVS and PNI were also adjusted. Interpretation & ConclusionsThese SNPs altered the survival and risk of death (HR) of BMC and TC differentially, that varied with clinical and risk factors.