Association between polymorphisms in genes related to DNA base-excision repair with risk and prognosis of oropharyngeal squamous cell carcinoma.

PURPOSE: We examined the influence of OGG1 c.977C>G (rs1052133), APEX1 c.444T>G (rs1130409), XRCC1 c.-77T>C (rs3213245), c.580C>T (rs1799782), c.839G>A (rs25489) and c.1196G>A (rs25487) single-nucleotide polymorphisms (SNPs), involved in base-excision repair (BER) pathway, on oropharyngeal squamous cell carcinoma (OPSCC) risk and prognosis. METHODS: Aiming to identify the genotypes, DNA from 200 consecutive OPSCC patients and 200 controls was analyzed by PCR-RFLP. The prognostic impact of genotypes of SNPs on progression-free survival (PFS) and overall survival of OPSCC patients was examined using the Kaplan-Meier estimates and Cox regression analyses. RESULTS: XRCC1 c.580CT or TT genotypes (19.5 vs. 11.0 %, P = 0.04) and XRCC1 TTGG haplotype from c.-77T>C, c.580C>T, c.839G>A and c.1196G>A SNPs (17.5 vs. 10.0 %, P = 0.04) were more common in patients with OPSCC than in controls. Carriers of combined genotypes of c.580C>T and TTGG haplotype of XRCC1 gene were under 3.35- and 3.22-fold increased risk of OPSCC than others. For survival analysis, we selected only patients with tumor at stage IV. The median follow-up time was 24.5 months. At 24 months of follow-up, PFS was shorter in patients with OGG1 c.977CC genotype when compared with others genotypes (35.5 vs. 52.1 %, log-rank test, P = 0.03). After multivariate Cox analysis, patients with OGG1 c.977CC genotype had more chance to present tumor progression when compared with others (HR 1.68, P = 0.02). CONCLUSIONS: Our data present, for the first time, evidence that inherited OGG1 c.977C>G; XRCC1 c.-77T>C, c.580C>T, c.839G>A and c.1196G>A abnormalities of DNA BER pathway are important determinants of OPSCC and predictors of patient outcomes.