Background: The aim of this study was to investigate the impact of hMLH1 polymorphisms on treatment outcomes in patients with oral squamous cell carcinoma (OSCC).
Methods: Genotypings were performed by direct DNA sequencing in peripheral blood leukocytes from 185 male OSCC patients. Patients received primary surgery with or without adjuvant radiotherapy. Two hMLH1 tag single nucleotide polymorphisms (SNPs)-rs1800734 (-93G>A in the promoter) and rs1540354 (in the third intron)-were chosen from the HapMap project. Overall survival (OS) and disease-free survival (DFS) were compared between different genotypes.
Results: The hMLH1 rs1800734 and rs1540354 polymorphisms were in weak linkage disequilibrium (r (2) = 0.456). OSCC patients with the rs1800734 AA genotype had a significantly poor prognosis in both OS and DFS. This SNP can also predict the outcomes of OSCC patients with postoperative adjuvant radiotherapy, especially in advanced stage; however, no significant differences in patient outcomes were found for the hMLH1 rs1540354 genotypes.
Conclusions: Our results demonstrate that the hMLH1 -93G>A SNP is found to be associated with patient outcomes in OSCC. This SNP can also predict their treatment outcome of radiotherapy.