Efficacy of postoperative adjuvant chemotherapy for esophageal squamous cell carcinoma: A meta‐analysis

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is the predominant type of esophageal cancer and most clinically curable patients are diagnosed with locally advanced disease. While the efficacy of preoperative treatment is relatively clear and well characterized, the effect of postoperative treatment, especially postoperative chemotherapy, remains controversial, and its role in the treatment strategy is obscure. We conducted an updated meta‐analysis to include recent developments. METHODS: A comprehensive search in the PubMed, Embase, and Cochrane databases was performed to identify studies published from the inception of each database to February 2018. The overall survival (OS) and disease‐free survival (DFS) rates of patients treated with and without postoperative chemotherapy were analyzed and compared. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used to assess the associations between postoperative chemotherapy and patient survival. Potential publication bias was assessed using Egger's line regression test. RESULTS: A total of nine studies, including three randomized controlled trials and six retrospective studies, were retrieved from the databases, comprising a total of 1684 cases. The results showed that postoperative chemotherapy could improve OS (HR 0.78, 95% CI 0.66–0.91; P = 0.002) and DFS (HR 0.72, 95% CI 0.6–0.86; P < 0.001). CONCLUSIONS: The current meta‐analysis supports postoperative chemotherapy as an independent favorable prognostic factor for ESCC, which could improve both OS and DFS.