Adjuvant radiochemotherapy vs. chemotherapy alone in gastric cancer: a meta-analysis.

BACKGROUND: As an adjuvant therapeutic strategy in advanced gastric cancer, both adjuvant chemotherapy (CTx) and postoperative radiochemotherapy (RCTx) can be considered. Both approaches have been shown to improve overall survival compared to resection alone. Several prospective randomized trials have compared the two postoperative concepts. METHODS: We performed a literature search to identify prospective randomized trials which compared adjuvant chemotherapy to adjuvant radiochemotherapy in patients with advanced gastric cancer. As effect sizes, we extracted hazard ratios (HR) as well as event rates from the included trials for the endpoints overall survival, disease-free survival and locoregional control. RESULTS: We identified seven studies that enrolled 1807 patients overall. Combined radiochemotherapy showed no significant improvement of overall survival in comparison to chemotherapy alone (HR = 0.93; 95%CI: 0.82-1.06; p = 0.28). For disease-free survival (HR = 0.86; 95%CI: 0.76-0.98; p = 0.023) and locoregional control (odds ratio [OR] = 0.56; 95%CI: 0.42-0.75; p = <0.001) we detected significant advantages from the addition of radiation to chemotherapy. A subgroup analysis demonstrated an improvement in survival when the radiochemotherapy protocol was not de-intensified. CONCLUSIONS: Adjuvant chemotherapy or radiochemotherapy demonstrate similar oncologic efficacy and therapy-associated toxicity. Individual patient characteristics should therefore determine the therapeutic approach in a multidisciplinary discussion. Irradiation added to standard-dose chemotherapy possibly results in a survival benefit.