Possible association between TGF-β1 polymorphism and oral cancer.

Oral squamous cell carcinoma (OSCC) is a worldwide health problem because it is a great cause of cancer morbidity and mortality. The transforming growth factor-β1 (TGF-β1) is involved in the regulation of numerous immunomodulatory processes. Thus, the aim of this case-control study was to investigate the possible association between the TGF-β1T869C polymorphism and oral cancer. The genomic DNA extracted from peripheral blood of 62 male smoker patients diagnosed with OSCC and 62 smokers without cancer was analysed. The C allele was significantly more prevalent in the oral cancer group than in the controls, and individuals carrying this allele had an estimated 2.73-fold greater relative risk of developing cancer compared with C allele noncarriers (OR = 2.73, 95% CI = 1.19-6.28). Although T allele was not statistically significant among the controls, considering the genotypic analysis, the TT homozygous genotype showed a protector effect in relation to oral cavity cancer (OR = 0.37, 95% CI = 0.16-0.84). Some clinicopathological features were also analysed for genotype distribution, and no significant differences were observed: tumour size (P > 0.70), nodal status (P > 0.10) and tumour stage (P > 0.70). This is the first report of a study assessing the importance of T869C TGF-β polymorphism in oral cancer. It is known that the TGF-β T869C variation results in a Leu10Pro substitution in the signal peptide sequence. Our results suggested that the C allele could increase TGF-β secretion which suppresses antitumour immune responses and may affect the OSCC risk.