Comparison of efficacy in adjuvant chemotherapy regimens in patients with radically resected gastric cancer: a propensity-matched analysis

BACKGROUND: We conducted the retrospective study to compare the efficacy of monotherapies versus two-drug regimens as postoperative chemotherapy for patients with radically resected gastric cancer. RESULT: At a median follow-up of 5.3 years, no significant difference in terms of OS was observed between two groups, neither before nor after matching. After matching, median DFS was statistically significant between group A and B (median, 67.5 vs 101.0 months, respectively; hazard ratio [HR], 0.65; 95% CI, 0.45 to 0.95; P=0.027), which meant doublets prolonged DFS. In subgroup analysis, the patients of stage III receiving doublet achieved better OS than those receiving monotherapy. People who received doublet and were less than 65 years old, or male patients, or in T4 stage, or in N2 stage, or receiving subtotal gastrectomy had better DFS than those with monotherapy. METHOD: A data set including 501 patients (monotherapy, n=107; doublet, n=394) was matched between the two groups (n=107 patients per group) using the propensity-matched study. The primary and secondary endpoint was overall survival(OS) and disease-free survival(DFS), respectively. Survival data was compared using the Kaplan-Meier method and Cox proportion hazards models for univariate and multivariate analyses. CONCLUSION: The dual regimens seemed not to add overall survival benefits to patients receiving curative gastrectomy, compared with single-agent fluoropyrimidine as postoperative chemotherapy. However, dual regimens showed better disease-free survival.