Relationship between the fluorouracil pathway gene and effect of chemotherapy in advanced gastric cancer after surgery

Abstract

Objective To investigate the relationship between the fluorouracil pathway gene and effect of chemotherapy in advanced gastric cancer after surgery. Methods 52 postoperative patients with advanced gastric cancer using FOLFOX4 6-cycles combined chemotherapy were collected to set up the database. The expression of thymidine synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyltransferase(OPRT) in tumor tissue and adjacent non-tumor tissue of 52 patients with advanced gastric cancer were measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The influence of fluorouracil pathway gene on chemotherapy was investigated. Results The TS-mRNA level in tumor tissue was significantly higher than non-tumor tissue (0.92±0.28 vs 0.71±0.30) (t = 3.730, P =0.001).OPRT-mRNA level in tumor tissue was positively correlated with the non-tumor tissue (r =0.45, P =0.001). No correlations were observed among other gene expressions. Patients whose high OPRT-mRNA gene expression in their tumors and non-tumor tissue showed an obviously better survival (t = 3.036, P =0.003;t = 2.713, P =0.009). Patients with low DPD-mRNA gene expression survived longer than those with high DPD-mRNA gene expression in tumor tissue with statistical significance(t = 2.708, P =0.009), whereas prolonged survival was observed in patients with high DPD-mRNA gene expression in non-tumor tissue (t = 2.616, P =0.012).Conclusion There is close relationships between chemotherapy in advanced gastric cancer and the expression of DPD-mRNA, OPRT-mRNA;while the expression of TS-mRNA have no relation with the survival time. Key words: Stomach neoplasms; Antineoplastic combined chemotherapy protcols; Treatment outcome; Molecular mechanisms of action