Neoadjuvant Chemoradiation Treatment for Resectable Esophago-Gastric Cancer: A Systematic Review and Meta-Analysis

Background: Neoadjuvant chemoradiation (CRT) remains controversial in the treatment of the oesophagus or gastro-oesophageal junction (GOJ) carcinomas. Methods: We conducted a meta-analysis to assess the efficacy and safety of Neoadjuvant CRT plus surgery comparing with neoadjuvant CT plus surgery or surgery alone. Feasible studies were searched from electronic databases. The outcomes of survival, R0 resection rate and adverse effects were analyzed. The outcomes were measured with relative risk (RR) and odds ratio(OR). Results: Seventeen records including 4095 patients were included. Neoadjuvant CRT improved 1-, 2-, 3- and 5-year survival. The relative risk (RR) [95% confidence interval (CI), P value] was respectively 1.08(1.03-1.14,0.002), 1.21(1.12-1.32,<0.00001), 1.31(1.09-1.58,0.004), 1.38(1.17-1.62, <0.001). In subgroup analysis, patients with squamous cell carcinoma benefited more survival advantage from neoadjuvant CRT than those with adenocarcinoma[1.23(1.15-1.33) vs1.11 (1.03-1.19)]. A significant advantage was observed in analysis of neoadjuvant CRT for PFS [1.32 (1.22-1.44),<0.00001]. Tests for DFS between neoadjuvant CRT and neoadjuvant CT or surgery alone were not statistically significant[1.06 (0.97-1.17,0.19)]. Neoadjuvant CRT was associated with higher R0 resection [2.58(1.75-3.82),<0.00001] and pCR rate [4.37(2.68-7.13),<0.00001]. Neoadjuvant CRT lowered the local recurrence rate [0.52(0.39-0.69),<0.00001] and didn't control distant metastasis rate[0.85(0.67-1.08), 0.19]. There was no evidence that neoadjuvant CRT increased the treatment-related mortality[1.27(0.95-1.71), 0.11]. Neoadjuvant CRT plus surgery did not increase the risk of adverse events morbidity[1.14(0.99-1.32), 0.08]. Conclusion: Patients with oesophagus or GOJ carcinomas can obtain a survival advantage from neoadjuvant CRT. The addition of radiation was efficacy and safe in range. However, these results need further high-quality prospective RCTs confirmation.