Role of chemotherapy for advanced/recurrent gastric cancer: an individual-patient-data meta-analysis

We conducted an individual-patient-data meta-analysis of the efficacy of chemotherapy on overall survival (OS) and progression-free survival (PFS) in advanced/recurrent gastric cancer (AGC). Our primary research question was whether the experimental arms of the trials included in the meta-analysis showed a benefit as compared with their corresponding control arms. MEDLINE (up to 2010), Cochrane Central Register of Controlled Trials, National Institutes of Health (NIH) trial registry and proceedings of major oncologic and gastrointestinal cancer meetings were searched. Randomised controlled trials for AGC closed to patient accrual before the end of 2006 were eligible. As of December 2010, individual patient data were available from 22 trials (4245 patients, representing 47% of the targeted data) of 55 eligible trials. The overall comparison of experimental arms with the corresponding control arms showed statistically significant differences in terms of both OS and PFS. Hazard ratio was 0.88 (95% confidence interval 0.82-0.94, P<0.0001) for OS and 0.81 (0.76-0.88, P<0.0001) for PFS. The results of the sub-analysis of adding a given chemotherapeutic agent to any chemotherapy confirm the results of the overall analysis, with a hazard reduction of 11% for OS (P<0.01) and 26% for PFS (P<0.0001). This meta-analysis of individual patient data shows that the additions of experimental chemotherapeutic agents to pre-existing control or standard regimens have produced a modest improvement in OS and PFS. Median survival remained below 1 year for all investigated chemotherapy regimens and none emerged as a clear standard.