Efficacy of adjuvant immunochemotherapy with polysaccharide k (PSK) for patients with curatively resected gastric cancer

Abstract

14038 Background: An anti-tumor effect of non-specific immunomodulators, mainly PSK and OK-432, via an immunological response has been reported and combination immunochemotherapy has been examined. However, the survival benefit of immunochemotherapy for patients with curatively resected gastric cancer was unclear in the world. We performed a meta-analysis in order to evaluate the survival effect of immunochemotherapy employing a biological response modifier Polysaccharide K (PSK) in Japan. Methods: We reassessed by means of meta-analysis of data with central randomization from 5164 patients enrolled in Japanese eight clinical trials. In all eight trials patients were followed up for at least 5 years after surgery and enrollment of the last patient and outcomes for standard chemotherapy were compared with those for chemotherapy plus PSK. The endpoint was 5-year survival odds ratio. Data were analyzed by using a weighted average of the log odds ratios (using Peto’s method). Results: The 5-year odds ratio for all eligible patients was 0.88 (95% confidence interval: 0.78–0.98; p=0.021). There was a significant heterogeneity between the trials (p=0.016). Conclusions: The results of this meta-analysis suggest that adjuvant immunochemotherapy with PSK can improve survival of patients with curatively resected gastric cancer. No significant financial relationships to disclose.