Lack of Association among Polymorphic Xenobiotic-metabolizing Enzyme Genotypes and the Occurrence and Progression of Oral Carcinoma in a Brazilian Population

Background: A case control association study was carried out to investigate polymorphisms in genes CYP1A1 (3801T>C), GSTM1, and GSTT1 (null genotypes) and oral squamous cell carcinoma (OSCC), including a correlation with some histopathological findings (tumor size, lymph node invasion and degree of tumor differentiation). Patients and Methods: The patients (n=91) and the controls (n=81) were matched by age, sex, ethnicity and smoking habits. The molecular analysis was carried out using Polymerase Chain Reaction-Restrict Length Polymorphisms PCR-RFLP (CYP1A1) and Multiplex-PCR (GSTM1/GSTT1). Results: No association was found for any of the studied genes: CYP1A1 (odds ratio (OR)=1.24; 95% Confidence Interval (CI)=0.67-2.31), GSTM1 (OR=0.61; CI 95%=0.33-1.11), and GSTT1 (OR=1.24; CI 95%=0.65-2.38). The analysis of combining genotypes also showed lack of association. Comparison with the histopathological findings did not, in general, detect any statistically significant differences. Conclusion: CYP1A1, GSTM1 and GSTT1 polymorphisms do not appear to influence the genetic susceptibility to OSCC or the progression to more advanced stages.