CYP1A1 rs4646903 T>C and rs1048943 A>G polymorphisms and the risk of colorectal cancer: An updated meta-analysis

Aim- To find an association between the CYP1A1 rs4646903 T>C and rs1048943 A>G polymorphisms and the risk of colorectal cancer by pooling recent studies. Methods- We perfomed a meta-anlysis on recently published articles searched using PubMed, Google and GoogleScholar search engines. After extensive search, a total of 33 publications were identified. Out of the 33 publications, a total of 18 recent eligile studies were included for the meta-analysis, which consisted of 2190 cases and 3977 controls for rs4646903 T>C and 2300 cases and 3789 control for rs1048943 A>G polymorphism. Results- The pooled analysis indicated that CYP1A1 rs4646903 T>C polymorphism is not a risk factor associated with colorectal cancer. The analysis of pooled data however, indicated a significant association between rs1048943 A>G and risk for colorectal cancer (Overdominant model: OR=0.97, 95%CI (0.86-1.10); Dominant model: OR=0.97, 95% CI (0.86-1.09); Recessive model: OR=0.98, 95% CI (0.74-1.30); GA vs. AA: OR=0.97, 95% CI (0.86-1.10); GG vs. AA: OR=0.97, 95% CI (0.74-1.27)). The heterozygous comparison of the genotypes has also shown the association. Further alcohol and tobacco consumption increase colorectal cancer  risk significantly. Our results are in line with the previous studies showing that CYP1A1 rs1048943 A>G polymorphism increases the risk of colorectal cancer and CYP1A1 rs4646903 T>C does not have any association with the risk of colorectal cancer. Conclusion- Our study suggests that CYP1A1 rs1048943 A>G acts as a risk factor of colorectal cancer. In addition to that, consumption of tobacco and alcohol have been shown to significantly increase the risk (p = 0.035). CYP1A1 rs4646903 T>C showed no significant positive association with colorectal cancer risk.