A consensus regarding standard adjuvant chemotherapy for curatively resected gastric cancer has not been obtained between Japan and the Western world. In order to evaluate the effect of a tegafur-based regimen (the most frequently used regimen in Japan) compared with a surgery-alone control, a meta-analysis was performed, investigating four clinical trials. After meticulous examination of each trial, trials with improper noncentralized randomization were excluded from the analysis. A total of 1197 patients were enrolled in the four relevant trials determined to be eligible for the meta-analysis (Nakajima 1984; Japan Clinical Oncology Group [JCOG] 8801, JCOG 9206-2, and National Surgical Adjuvant Study of Gastric Cancer [NSASGC], in which a tegafur-based regimen was used for chemotherapy and central randomization was performed. The endpoint was overall survival, and a common hazard ratio was estimated. The 5-year overall survival rates differed among the trials because of differences in the background disease status. But there was no heterogeneity (P = 0.235) of treatment effect. The estimated common hazard ratio was 0.75, with a 95% confidence interval of 0.58–0.98. The treatment effect of the tegafur-based agent was shown to be statistically significant (P = 0.037) compared with surgery-alone therapy (n = 1179). From the results of the above meta-analysis, it is suggested that chemotherapy with a tegafur-based agent after surgery can improve the survival of patients with curatively resected gastric cancer. The Global Advanced/Adjuvant Stomach Tumor Research through International Collaboration (GASTRIC) group is conducting two individual patient data meta-analyses, testing post-operative adjuvant chemotherapy for resect-able gastric cancer and chemotherapy for advanced gastric cancer. It is expected to determine and quantify the role of adjuvant chemotherapy in detail from the GASTRIC.
Adjuvant chemotherapy Gastric cancer Meta-analysis