Previous epidemiological studies have evaluated the association between the ABCB1 polymorphism and the risk of breast cancer with conflicting results. Hence, we conducted a meta-analysis of the ABCB1 gene and risk of breast cancer to obtain the most reliable estimate of the association. PubMed, Embase, and Web of Science databases were searched. A total of eight studies including 3,829 cases and 6,193 controls were identified. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of associations between the ABCB1 C3435T and rs2214102 G>A polymorphisms and risk of breast cancer. Of these studies, only one deviated from Hardy–Weinberg equilibrium. Summary estimates indicated that the ABCB1 C3435T polymorphism was not associated with increased risk of breast cancer in the allele contrast model (T vs. C, pooled OR = 1.15; 95% CI = 0.89–1.48); the co-dominant model (CT vs. CC, OR = 1.12 [0.86–1.46] and TT vs. CC, OR = 1.30 [0.79–2.15]); the dominant model (OR = 0.80 [0.63–1.02]; and the recessive model (OR = 0.83 [0.57–1.22]). In the sensitivity analysis by ethnicity, no statistically significant associations were detected in Asians. However, in Caucasian women the T allele contrast model and the TT genotype were each associated with increased risk: T vs. C, pooled OR (95% CI) = 1.26 (1.04–1.52) and TT vs. CC, OR = 1.48 (1.04–2.11). Accordingly, the dominant model yielded statistically significant results (pooled OR = 0.71, 95% CI: 0.52–0.96) but not with the allele contrast model or the co-dominant model. There was evidence of publication bias (P = 0.02 for recessive model). In conclusion, there is limited evidence to indicate that the ABCB1 C3435T and rs2214102 G>A polymorphisms are associated with increased risk of breast cancer.
ABCB1 C3435T and rs2214102 G>A polymorphismsBreast cancerSusceptibilityMeta-analysis