Effects of MDR1 Gene Polymorphism on Efficacy and Hematotoxicity of Epirubicin-Based Regimen in Patients with Breast Cancer in Southwest China

Objective: To investigate the predictive value of multi-drug resistance gene (MDR1) polymorphism in the efficacy and hematological toxicity of chemotherapy regimen based on Epirubicin in patients with breast cancer in Southwest China.\r\nMethods: Patients who received Epirubicin-based chemotherapy were included, and polymorphism of C1236T, G2677T/A and C3435T were detected by time-of-flight mass spectrometry (TOF-MS). The correlation between different genotypes and chemotherapy efficacy and blood toxicity were evaluated.\r\nResults: A total of 102 patients were included, 44 of them were treated with neoadjuvant chemotherapy. There was no significant correlation between all genotypes and alleles of the three SNPs and the efficacy of neoadjuvant chemotherapy regimen containing Epirubicin in patients with breast cancer. There was a significant correlation between C3435T polymorphism and grade ?-? leukopenia in patients with breast cancer, the incidence of grade ?-? leukopenia in patients with C allele was significantly lower than that in patients with T allele.\r\nConclusion: T allele of C3435T polymorphism may be a risk factor for grade ?-? leukopenia in patients with breast cancer after chemotherapy.