EffectofGSTP1geneticvariationontherecurrenceriskandprognosisofcolorectal cancerpatients received postoperative adjuvant chemotherapy / 中国肿瘤生物治疗杂志

ABSTRACT

@#[Abstract] Objective: To investigate the influence of glutathione S-transferase P-1 (GSTP1) genetic variation on the recurrence risk and prognosis of colorectal cancer (CRC) patients received postoperative adjuvant chemotherapy. Methods: The clinical data of 195 CRC patients, who received postoperative adjuvant chemotherapy in the Department of Gastroenterology of the FirstAffiliated Hospital of Zhengzhou University from January 2010 to December 2018, were collected for this study. 5-fluorouracil (5-FU) based adjuvant chemotherapy was given after surgical resection. The recurrence status of the patients was assessed during hospitalization period, and the long-term survival data of patients were obtained by telephone follow-up after finishing the scheduled adjuvant chemotherapy. GSTP1 genotyping was performed with the DNA extracted from peripheral blood specimens, and its correlation with patients’clinical characteristics wasanalyzed.Additionally, RNAwasextractedfrom peripheral blood mononuclear cell (PBMC) specimens of some CRC patients that prior to chemotherapy for GSTP1 mRNA expression analysis. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and adjusted by multivariate Cox regression model. Results: The median disease-free survival (DFS) of the 195 CRC patients was 4.8 years, and the median overall survival (OS) was 6.2 years. Polymorphism analysis indicated that the I105VlocusofGSTP-1coding region was correlated with prognosis. The prevalence of I105V in the study population AA genotype of 135 cases (69.23%), AG genotype of 56 cases (28.72%) and GG genotype of 4 cases (2.05%), the minor allele frequency of I105V was 0.16. The genotype distribution was in accordance with Hardy-Weinberg equilibrium (P>0.05). The analysis of recurrence risk and prognosis found that the median DFS of patients with AA genotype and AG/GG genotype was 5.7 and 3.9 years respectively (P<0.01), while the median OS of two groups of patients was 7.0 and 4.5 years respectively (P<0.01). The multivariate Cox regression results indicated that AG/GG genotype was an independent factor for OS (OR=1.54, P<0.05). The mRNA expression of GSTP1 in PBMC of the patients with AG/GG genotypes were significantly higher than those patients with AA genotype (P<0.01). Conclusion: GSTP1 I105V genetic variation influences the recurrence risk and prognosis of CRC patients received postoperative adjuvant chemotherapy possibly via mediating the mRNAexpression of GSTP1.