BACKGROUND: Although various individual studies have evaluated the correlation between cytochrome P450 1A1 (CYP1A1) polymorphisms and breast cancer, the results remain inconclusive. To further evaluate the influence of CYP1A1 polymorphisms on breast cancer risk, we conducted a meta-analysis in the Chinese population. METHODS: Studies were identified using PubMed and Chinese databases through December 2015. Pooled odd ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strengths of these associations. RESULTS: This meta-analysis included 6 studies with 1837 breast cancer cases and 1970 controls. No significant association of CYP1A1 T3801C polymorphism and breast cancer was observed in the Chinese population (C vs. T: OR = 1.01, 95% CI = 0.74 - 1.37; CC vs. TT: OR = 1.08, 95% CI = 0.65 - 1.78; CC vs. TT + CT: OR = 1.02, 95% CI = 0.84 - 1.24; CC + CT vs. TT: OR = 1.01, 95% CI = 0.63 - 1.60). The pooled estimate for CYP1A1 A2455G polymorphism was not statistically significantly associated with breast cancer in overall and subgroup analyses. CONCLUSIONS: This meta-analysis provided evidence that CYP1A1 T3801C and A2455G variants might not be risk alleles for breast cancer susceptibility in Chinese individuals. Further studies conducted in other ethnic groups are required for definite conclusions.
BACKGROUND: Although various individual studies have evaluated the correlation between cytochrome P450 1A1 (CYP1A1) polymorphisms and breast cancer, the results remain inconclusive. To further evaluate the influence of CYP1A1 polymorphisms on breast cancer risk, we conducted a meta-analysis in the Chinese population. METHODS: Studies were identified using PubMed and Chinese databases through December 2015. Pooled odd ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strengths of these associations. RESULTS: This meta-analysis included 6 studies with 1837 breast cancer cases and 1970 controls. No significant association of CYP1A1T3801C polymorphism and breast cancer was observed in the Chinese population (C vs. T: OR = 1.01, 95% CI = 0.74 - 1.37; CC vs. TT: OR = 1.08, 95% CI = 0.65 - 1.78; CC vs. TT + CT: OR = 1.02, 95% CI = 0.84 - 1.24; CC + CT vs. TT: OR = 1.01, 95% CI = 0.63 - 1.60). The pooled estimate for CYP1A1A2455G polymorphism was not statistically significantly associated with breast cancer in overall and subgroup analyses. CONCLUSIONS: This meta-analysis provided evidence that CYP1A1T3801C and A2455G variants might not be risk alleles for breast cancer susceptibility in Chinese individuals. Further studies conducted in other ethnic groups are required for definite conclusions.