ABCB1 C3435T polymorphism is associated with leukemia susceptibility: evidence from a meta-analysis

INTRODUCTION AND OBJECTIVE Many studies have been conducted on the association between the adenosine triphosphate-binding cassette, subfamily B, member 1 (ABCB1) gene C3435T polymorphism and leukemia risk, however, the previously published findings remain controversial. Thus, a meta-analysis was carried out to accurately evaluate the effect of this polymorphism on leukemia susceptibility. METHODS A computerized literature search was conducted of PubMed, Elsevier database, the China National Knowledge Infrastructure database, and Wanfang Database, to find published case-control studies exploring the relationship between ABCB1 C3435T polymorphism and leukemia risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of association. RESULTS A total of 17 studies of 2,431 cases and 3,028 controls were included in this meta-analysis. The results of overall comparisons suggest that there is a significant association between ABCB1 C3435T polymorphism and leukemia risk under two genetic models (TT vs CC: OR=1.39, 95% CI=1.04-1.84, P=0.02; CT+TT vs CC: OR=1.20, 95% CI=1.06-1.36, P=0.004). In the subgroup analyses by ethnicity, age, and leukemia subtype, a significant association was found in Caucasian (CT vs CC: OR=1.22, 95% CI=1.03-1.45, P=0.02; TT vs CC: OR=1.34, 95% CI=1.10-1.64, P=0.004; CT+TT vs CC: OR=1.27, 95% CI=1.08-1.49, P=0.004), adult leukemia (CT vs CC: OR=1.46, 95% CI=1.17-1.83, P=0.001; CT+TT vs CC: OR=1.43, 95% CI=1.01-2.03, P=0.04), and lymphocytic leukemia (TT vs CC: OR=1.73, 95% CI=1.19-2.51, P=0.004; TT vs CC+CT: OR=1.62, 95% CI=1.10-2.38, P=0.01; CT+TT vs CC: OR=1.28, 95% CI=1.10-1.48, P=0.001). CONCLUSION The meta-analysis suggests that ABCB1 C3435T polymorphism is associated with increased risk of leukemia.