Background: This study aimed to explore the clinical correlation of single-nucleotide polymorphisms of thymidylate synthase (TS) and runt-related transcription factor 1 (RUNX1) in patients with postoperative stage II and III gastric cancer (GC).
Patients and methods: Samples were obtained from 661 patients with postoperative stage II and III GC. TS (rs34743033) and RUNX1 (rs2014300) were genotyped in 261 patients who received postoperative basic platinum and fluorouracil chemotherapy regimens and 400 patients who did not accept chemotherapy.
Results: TS (rs34743033) variant genotypes significantly prolonged the median overall survival (OS) time compared to the patients who only received adjuvant chemotherapy (HR 1.604, 95% CI 1.068–2.410, p =0.021). Moreover, 3R/3R variant genotypes were demonstrated to have a positive effect on the OS of patients who received chemotherapy based on cisplatin (HR 1.754, 95% CI 1.041–2.954, p =0.031) compared to oxaliplatin. A stratification analysis indicated that 2R/3R and 2R/2R variant genotypes were associated with inferior survival in GC patients with intestinal-type tumors, tumor less than 5 cm in size, and poorly differentiated tumors (p <0.05). However, RUNX1 (rs2014300) AA genotypes markedly increased the risk of death in GC patients compared with the GG/GA genotypes (p =0.007), but no significant difference was observed between chemotherapy based on platinum. The stratification analysis showed that the GA/AA genotype was significantly associated with inferior survival in well to moderately differentiated tumors (HR 2.001, 95% CI 1.082–3.703, p =0.023).
Conclusion: These preliminary results indicated that the two polymorphisms had a significant effect on postoperative adjuvant chemotherapy. TS (rs34743033) and RUNX1 (rs2014300) may be used as biomarkers to predict prognosis and select chemotherapy regimens in GC patients.
Keywords: thymidylate synthase, runt-related transcription factor 1, single-nucleotide polymorphisms, adjuvant chemotherapy, gastric cancer