Chemoradiation Therapy Versus Chemotherapy Alone for Gastric Cancer After R0 Surgical Resection: A Meta-Analysis of Randomized Trials

Objective: Current national guidelines include category 1 recommendations for perioperative chemotherapy or adjuvant chemoradiation with surgical resection for patients with stage IB-IIIB gastric cancer. We conducted a meta-analysis of randomized trials in which chemotherapy was prospectively tested against chemoradiation with surgical resection. Methods: We electronically searched PubMed and EMBASE for randomized, controlled clinical trials involving patients with gastric adenocarcinoma, status post-R0 resection. The interventions compared were adjuvant chemotherapy versus chemoradiation, with any chemotherapy regimen. The primary outcomes of interest were disease-free survival and overall survival. The Mantel-Haenszel random-effects model was used to calculate effect sizes. Results: Six trials that included 1,171 patients were evaluated; 599 were randomized to adjuvant chemoradiation and 572 to chemotherapy alone. Chemoradiation was associated with a significant increase in disease-free survival (odds ratio 1.48, 95% confidence interval 1.08-2.03) when compared to chemotherapy alone. However, there was no significant difference in overall survival (odds ratio 1.27, 95% confidence interval 0.95-1.71). Five trials found no statistically significant differences in toxicities between the two groups. Conclusion: In patients with gastric cancer status post-R0 resection, adjuvant chemoradiation was associated with higher disease-free survival when compared to chemotherapy alone. It remains appropriate to design trials testing new systemic agents with radiotherapy.