ABSTRACT
OBJECTIVE To investigate the effects of GSTP1， XRCC1， ABCB1， MTHFR gene polymorphisms on efficacy and toxic effect of chemotherapy regimen containing oxaliplatin in patients with stage Ⅲ and Ⅳ colorectal cancer patients. METHODS Clinical data of 76 patients with stage Ⅲ and Ⅳ colorectal cancer who received chemotherapy regimen containing oxaliplatin （XELOX，FOLFOX） were collected from the Second Affiliated Hospital of Soochow University from September 2018 to March 2020. The correlation of genotypes with progression-free survival （PFS） and toxic effect was analyzed by using univariate and multivariate COX regression model. RESULTS Carriers of the ABCB1 3435T＞C locus C allele （TC/CC） had a significantly higher risk of progression compared to TT genotype patients [HR＝2.39， 95%CI （1.05，5.50）， P＝0.038]. The risk of progression in patients at stage Ⅳ was significantly higher than those at stage Ⅲ [HR＝8.11， 95%CI（3.39，19.40）， P＜0.001]. Chemotherapy regimen， Karnofsky performance status score and tumor site had no significant effect on disease progression （P＞0.05）. Mutations in gene loci were not correlated with adverse reactions （P＞0.05）. CONCLUSIONS Patients carrying ABCB1 TC/CC and receiving chemotherapy regimen containing oxaliplatin have a higher risk of disease progression， which may be associated with longer PFS in patients （TT genotype） with stage Ⅳ colorectal cancer receiving the chemotherapy， while GSTP1， XRCC1， and MTHFR gene polymorphisms have no significant impact.