Impact of Body Mass Index on Surgical Outcomes after Esophagectomy for Patients with Esophageal Squamous Cell Carcinoma

Patients with overweight reportedly have more comorbidities, including diabetes mellitus and cardiovascular disease, and longer operating times as well as more blood loss during surgery compared with those with normal weight. However, the impact of overweight on the short-term outcome after transthoracic esophagectomy for patients with esophageal squamous cell carcinoma (ESCC) remains unclear. We hypothesized that overweight has a negative impact on short-term surgical outcomes after esophagectomy for patients with ESCC. A total of 304 patients who underwent transthoracic esophagectomy for ESCC were included in this study. Body mass index (BMI) was classified into three categories, < 18.49, 18.50-24.99, and > 25.00 (kg/m(2)), defined as low, normal, and high BMI, respectively, according to the World Health Organization criteria. We investigated the association of BMI status with patient demographics and surgical outcomes after esophagectomy for patients with ESCC. In addition, overall survival and relapse-free survival stratified by BMI were compared. Fifty-nine (19.4 %) and 41 (13.4 %) patients were classified to low BMI and high BMI, respectively. The high-BMI group had significantly higher comorbidity rates of diabetes mellitus (p < 0.01) and anastomotic leakage (p = 0.011) than the normal-BMI group. There were no significant association between high BMI and another various complications except for an anastomotic leakage, severe complications defined by Clavien-Dindo classification and in-hospital mortality. In multivariate analysis, high BMI was a significant risk factor for anastomotic leakage (p = 0.030, hazard ratio; 3.423, 95%CI; 1.128-10.38). On the other hand, no significant association was observed between low BMI and short surgical outcomes. There were no significant differences in overall and relapse-free survival among the three BMI groups in univariate and multivariate analysis (p = 0.128 and p = 0.584, respectively). The surgical treatment should not be denied for patients with ESCC due to overweight and underweight. However, intraoperative prevention and postoperative careful monitoring for anastomotic leakage might be required after esophagectomy for overweight patients with ESCC.