CYP1A1 MspI polymorphism and the risk of oral squamous cell carcinoma: Evidence from a meta-analysis.

Numerous case-control studies have investigated whether the CYP1A1 gene polymorphism is involved in the occurrence of oral squamous cell carcinoma (OSCC); however, the conclusions are inconsistent. In order to further explore the correlation and obtain a strong conclusion, a meta-analysis was performed to systematically assess the association between the CYP1A1 MspI polymorphism and risk of OSCC. In the present meta-analysis, the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were used to assess the association. The statistical analyses were performed with STATA 11.0 software. The heterogeneity was assessed by Q test and I2test. The final analysis included 10 studies of 1,505 cases and 1,967 controls. The overall results suggested that the CYP1A1 MspI polymorphism was significantly associated with an increased risk of OSCC (CC+TC vs. TT: OR, 1.31; 95% CI, 1.01-1.70; P=0.043; CC vs. TC+TT: OR, 2.38; 95% CI, 1.58-3.58; P<0.001; CC vs. TT: OR, 2.52; 95% CI, 1.60-3.96; P<0.001; and C vs. T: OR, 1.45; 95% CI, 1.15-1.83; P<0.001). In a stratified analysis by ethnicity, a statistically significant correlation existed in the Asian population, but not mixed-race and Caucasian populations. In conclusion, despite several limitations, the present meta-analysis established that the CYP1A1 MspI polymorphism may be a risk factor for OSCC, particularly among the Asian population.