Neoadjuvant chemoradiation therapy for resectable esophago-gastric adenocarcinoma: a meta-analysis of randomized clinical trials

Background: The efficacy and safety of preoperative chemoradiation therapy (CRT) for advanced esophago-gastric adenocarcinoma are still in question, and the prognosis of these patients is poor. Methods: We systematically searched electronic databases from January 1990 to July 2014. The primary outcome was overall survival. The secondary outcomes were a R0 resection rate, positive rate of lymph node metastasis, postoperative recurrence rate, pathological complete response (pCR) rate and perioperative mortality. Overall survival was measured with a hazard ratio (HR), while other secondary outcomes were measured with an odds ratio (OR). Results: Seven randomized controlled trials (RCTs) including 1085 patients were searched and, of these, 869 had adenocarcinoma. Patients receiving preoperative CRT had a longer overall survival (HR 0.74; 95% confidence interval (CI) 0.63-0.88), higher likelihood of R0 resection and greater chance of pCR, while they had a lower likelihood of lymph node metastasis and postoperative recurrence. The difference of perioperative mortality was non-significant. In addition, the result of the comparison between preoperative CRT and preoperative chemotherapy (CT) in two RCTs was non-significant. Conclusion: Patients with resectable esophago-gastric adenocarcinoma can gain a survival advantage from preoperative CRT. However, limited to the number of RCTs, the effect of adding radiotherapy to preoperative CT separately is still uncertain and more high-quality prospective trials are needed.