ABCB1 polymorphism as a prognostic factor in breast cancer patients with neoadjuvant chemotherapy.

Abstract

1038 Background: Expression of the adenosine triphosphate-binding cassette B1(ABCB1) transporter and P-glycoprotein are associated with resistance to anticancer drugs. The purpose of this thesis was to investigate the role of single nucleotide polymorphism (SNP) in the ABCB1 and CYP3A genes in breast cancer patients who were treated with neoadjuvant docetaxel and doxorubicin chemotherapy. Methods: Stage II or III breast cancer patients were treated with 3 cycles of neoadjuvant, after which the patients received curative surgery and adjuvant chemotherapy with the same regimen. The polymorphisms of ABCB1 (C3435T, G2677T/A, and C1236T) and CYP3A were genotyped. The correlation of genetic polymorphisms of ABCB1, CYP3A, and clinical outcomes was analyzed. Results: Among the 216 patients, ABCB1 3435TT genotype had a longer OS than CT/TT. With univariate analysis, good PS, invasive ductal carcinoma, initial operable stage, ER-positivity, non-triple negative phenotype, breast conserving surgery and the TT genotyp...