Role of TNFSF15 variants in oral cancer development and clinicopathologic characteristics.

Tumour necrosis family superfamily (TNFSF) member 15 (TNFSF15), encoded by TNFSF15, regulates immune responses and inflammation. However, the roles of TNFSF15 single-nucleotide variants (SNVs; formerly SNPs) in oral cavity squamous cell carcinoma (OCSCC) remain unclear. This case-control study included 2523 participants (1324 patients with OCSCC [52.5%] and 1199 healthy controls [47.5%]). The effects of TNFSF15 rs3810936, rs6478108 and rs6478109 on cancer development and prognosis were analysed by real-time PCR genotype assay. The Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) databases were used to validate our findings. The results demonstrated that the patients with altered TNFSF15 SNVs had poorer histological differentiation than did those with wild-type alleles. TNFSF15 SNVs were significantly associated with moderate-to-poor histological differentiation in univariate logistic regression. In the GTEx database, the expression of altered TNFSF15 SNVs in whole blood was lower than that of wild-type alleles. However, the expression of altered SNVs in the upper aerodigestive mucosa was higher than that of wild-type alleles. In the TCGA database, the patients with higher TNFSF15 expression had shorter overall survival than did those with lower TNFSF15 expression, especially for human papillomavirus-negative and advanced staging groups. In conclusion, although TNFSF15 SNVs did not affect OCSCC development, the patients with altered TNFSF15 SNVs exhibited poorer histological differentiation. The patients with higher TNFSF15 expression had poorer prognosis than did those with lower TNFSF15 expression.