The correlation between high body mass index and survival in patients with esophageal cancer after curative esophagectomy: evidence from retrospective studies.

OBJECTIVE: To investigate the predictive value of high body mass index (H-BMI) on the survival of patients with esophageal cancer (EC) after curative esophagectomy. METHODS: Studies were systematically identified to investigate the relationship between overweight and obese (H-BMI) and clinical outcomes in EC patients treated with curative esophagectomy. Measured clinical outcomes were disease-free survival (DFS) and overall survival (OS). The pooled hazard ratio (HR) with 95% confidence interval (CI) was estimated. Subgroup analyses were performed according to tumour type and body mass index (BMI). RESULTS: Fourteen studies with 4823 cases were included in the final pooled quantitative analysis. In EC patients overall, H-BMI was associated with improved DFS (HR, 0.83; 95% CI: 0.75-0.90) and OS (HR, 0.79; 95 % CI: 0.73-0.85), as compared with normal BMI. The results were consistent with those who were overweight. Among patients with esophageal adenocarcinoma (EAC), a better prognosis, as reflected by OS, was observed with H-BMI (HR, 0.81; 95% CI: 0.73-0.89). The same results were also observed in EAC patients who were obese and overweight. In contrast, among patients with esophageal squamous cell carcinoma (ESCC), H-BMI was associated with a worse prognosis, as reflected by DFS (HR, 2.26; 95% CI: 1.29-3.24). CONCLUSIONS: H-BMI has distinctly different impacts on the postoperative survival of EAC and ESCC patients. H-BMI is a potential predictor for better prognosis in EC patients overall, and particularly in EAC patients, treated with curative esophagectomy. However, in ESCC patients, H-BMI is a potential predictor for a worse prognosis of postoperative survival.