Correlation of OCA2 gene rs4778137 single nucleotide polymorphism with the prognosis of early breast cancer patients receiving epirubicin-based regimen chemotherapy / 肿瘤研究与临床

ABSTRACT

Objective:To investigate the correlation of OCA2 gene rs4778137 single nucleotide polymorphism with the prognosis of early breast cancer patients receiving epirubicin-based regimen chemotherapy.Methods:The data of 152 patients with early breast cancer who received epirubicin combined with cyclophosphamide and docetaxel (EC-T regimen) chemotherapy in the First People's Hospital of Ziyang from April 2010 to January 2013 were retrospectively analyzed. OCA2 gene rs4778137 single nucleotide polymorphism of peripheral venous blood before chemotherapy was detected. The follow-up was up to April 2017, recurrence and disease-free survival (DFS) were analyzed. DFS of patients with different rs4778137 locus genotype in patients with different estrogen receptor (ER)/progesterone receptor (PR) expressions, human epithelial factor receptor 2 (HER2) expressions and Ki-67 positive index were analyzed.Results:The median follow-up time was 60 months (28-80 months). There were 2 cases of lost follow-up and 26 cases of recurrence. Among 150 patients with follow-up results, 68 cases (45.33%) of rs4778137 genotype were CC genotype, 47 cases (31.33%) of GC genotype and 35 cases (23.33%) of GG genotype. There were significant differences in N staging, HER2 expression and ER/PR expression among patients with or without recurrence ( χ2 value was 5.79, 6.08 and 6.05; P value was 0.016, 0.014 and 0.014, respectively). The 5-year DFS rate of 150 breast cancer patients was 82.2%, and there was no significant difference in DFS among patients with different rs4778137 locus genotype ( χ2 = 2.35, P = 0.167). Cox regression analysis showed that N staging and ER/PR expression were independent influencing factors of DFS in breast cancer patients (all P < 0.05). Among 71 ER/PR-negative patients, there was a statistically significant difference in DFS of patients with different rs4778137 locus genotype ( χ2 = 6.52, P = 0.030). Among 79 ER/PR-positive patients, 60 HER2-positive patients and 90 HER2-negative patients, 118 cases with Ki-67 positive index >14% and 32 cases with Ki-67 positive index≤14%, there were no statistically significant differences in DFS of patients with different rs4778137 locus genotype (all P > 0.05). Conclusions:The DFS of ER/PR-negative patients with early breast cancer who received epirubicin-based regimen chemotherapy is correlated with OCA2 gene rs4778137 single nucleotide polymorphism. Patients with GG genotype at rs4778137 locus have better prognosis.