Madrid-Paredes, AdelaCañadas-Garre, MarisaSánchez-Pozo, AntonioExpósito-Ruiz, ManuelaCalleja-Hernández, Miguel Ángel2023-01-252023-01-252017-09-21http://hdl.handle.net/10668/11777The ABCB1 gene encodes the P-glycoprotein, an efflux pump for some antineoplastic agents which acts as a resistance mechanism to chemotherapy. Three SNPs (C3435T, C1236T and G2677T/A), are the most widely studied in ABCB1. The inconsistent conclusions about the association of these polymorphisms and the response to chemotherapy in breast cancer (BC) patients prompted us to conduct a meta-analysis. A total of nine (770 patients), five (566 patients) and three studies (367 patients) relating the ABCB1 C3435T, C1236T and G2677T/A polymorphisms respectively, were included. The main analysis revealed a lack of association between ABCB1 polymorphisms and response to chemotherapy in every genetic model: C3435T (dominant OR: 0.888; 95%CI: 0.558-1.413), C1236T (dominant OR: 1.968; 95%CI: 0.609-6.362) and G2677T/A (GG vs GT + GA + TT + TA + AA OR: 0.854; 95%CI: 0.418-1.744). Stratification by ethnicity, cancer type and response criteria did not change the pattern of results. The available evidence indicates that three polymorphisms within ABCB1; C3435T, C1236T and G2677T/A, cannot be considered a reliable predictor of response to chemotherapy in BC patients.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/ABCB1BreastC1236TC3435TCancerMeta-analysisATP Binding Cassette Transporter, Subfamily BAntineoplastic Combined Chemotherapy ProtocolsBiomarkers, TumorBreast NeoplasmsFemaleHumansPolymorphism, Single NucleotidePrognosisresearch article29113667open access10.1016/j.suronc.2017.09.0041879-3320https://pureadmin.qub.ac.uk/ws/files/135177280/ABCB1_gene_polymorphisms_and_response_to_chemotherapy_in_breast_cancer_patients_a_meta_analysis_Main_text_modified.pdf