Clinical characteristics and outcomes of patients enrolled in clinical trials compared with those of patients outside clinical trials in advanced gastric cancer.

Abstract

Participating in clinical trials could give cancer patients potential benefits such as experimental treatment, meticulous follow-up, and management of toxicities. We hypothesized that patients participating in clinical trials would achieve better survival outcomes than those not enrolled in trials. We assessed whether the trial effect can improve survival for patients with advanced gastric cancer. We retrospectively enrolled metastatic or recurrent gastric cancer patients who received palliative chemotherapy from January 2010 to December 2012. All patients in this study received fluoropyrimidine and platinum as the first-line palliative chemotherapy. Patients participating in clinical trials were matched 1:1 with patients not enrolled in trial based on propensity-score. A total of 229 patients were identified, 83 (36.2%) among them participated in 14 clinical trials for advanced gastric cancer. The number of patients enrolled in phase I, II and III trials were 10, 54 and 19, respectively. The median overall survival of the total study patients was 13.0months (95% confidence interval, 10.7-15.3 months). In the propensity-score matched population, a total of 78 matched pairs of patients were generated. The median overall survival of the 78 patients who participated in the clinical trials was 6 months longer than that of patients not enrolled in trials, although this benefit was marginally significant (15 months vs 9 months, hazard ratio, 0.709; p=0.068). Participation in clinical trials was a significant factor to predict better overall survival in multivariate analysis (hazard ratio, 0.533, p=0.001). Trial effect may contribute to prolongation of overall survival in patients who participate in clinical trials for advanced gastric cancer. Physicians may discuss trial effect to encourage participation in clinical trials.