ABCB1 (rs1128503) polymorphism and response to chemotherapy in patients with malignant tumors-evidences from a meta-analysis.

Numerous papers have reported ABCB1 polymorphisms are associated with the response to chemotherapy of cancers. The inconclusive results call for a comprehensive analysis, for the sample size of the published studies is comparatively small. Therefore, a comprehensive meta-analysis was performed on the basis of the published studies for an accurate estimation of such association. Altogether 8 comparative studies including 2463 cancer patients were involved in our meta-analyses. ABCB1 C1236T (rs1128503) polymorphism was shown to be associated with tumor response to chemotherapy in cancer patients under the dominant model (OR=1.72, 95% CI=1.09-2.73, P=0.177, I(2)=36.60%) and additive model (OR=1.99, 95% CI=1.39-2.85, P=0.222, I(2)=25.90%). A subgroup meta-analysis indicated a significant association under dominant model between ABCB1 C1236T (rs1128503) polymorphism and breast cancer in the Asians (OR=2.15, 95% CI=1.22-3.77, P=0.210, I(2)=33.70%). These results suggest that ABCB1 C1236T (rs1128503) might contribute to the tumor response to chemotherapy in cancers from the Asians, especially in the osteosarcoma and breast cancer.