The CYP1A1 T3801C polymorphism and CRC risk
Overall, the CYP1A1 T3801C polymorphism was not associated with CRC risk when all the selected studies were merged, as shown in Table 2. Then, subgroup analyses according to ethnicity, geographic region, location of CRC, gender, and smoking, a significant association was only observed in rectal cancer (CC vs. TT: OR = 0.73, 95% CI: 0.55–0.97; CC vs. (TT + TC): OR = 0.75, 95% CI: 0.57–0.98; C vs. T: OR = 0.89, 95% CI: 0.80–1.00) and females (TC vs. TT: OR = 1.27, 95% CI: 1.00–1.62). However, after BFDP correction, associations did not be observed in rectal cancer (CC vs. TT: BFDP = 0.998; CC vs. (TT + TC): BFDP = 0.998; C vs. T: BFDP = 0.999) and females (TC vs. TT: BFDP = 0.999).