Chemotherapeutic Responsibility according to Polymorphism of ERCC1, XRCC1 and GSTP1 in Gastric Cancer Patients Receiving Oxaliplatin Based Chemotherapy

ABSTRACT

PURPOSE: The platinum-based modified FOLFOX-6 has been reported as an acceptable chemotherapeutic regimen in treatment of advanced gastric cancer patients. The response rate and drug-induced toxicity of platinum-based chemoagents is different according to several gene polymorphism such as ERCC1, XRCC1 and GSTP1 genes, which were related with therapeutic mechanisms. We aimed to evaluate the effect of gene polymorphism and determine the possibility as prediction factor for responsibility in advanced and recurrent gastric cancer patients treated with modified FOLFOX-6 regimen. METHODS: This study was conducted with 55 patients. We sampled 20 ml of peripheral blood to isolate DNA from lymphocytes, and identified genotypes of 3 genes (ERCC1, XRCC1, GSTP1) by PCR-RFL of extracted DNA. Based on medical records, retrospective analysis was made on the patients' clinical characteristics. RESULTS: The overall response rate to modified FOLFOX-6 was 40.0% (22/55). In polymorphism of ERCC1 C8092A, the wild type (CC) showed a statistically significantly lower response rates to chemoagents than the mutant type (CA/AA). In the subtypes of ERCC1 C118T, however, the wild type (CC) showed statistically significantly lower hematological toxicity than the mutant type (CA/AA). But, there was no statistically significance in survival analysis. CONCLUSION: We suggest that ERCC1 gene polymorphism is clinically more adequate as a feasible factor for predicting the response rate and toxicity of modified FOLFOX-6 regimen in gastric cancer patients.