Relationship between the Body Mass Index and Tumor Site Postoperative Complications and Prognosis in Gastric Adenocarcinoma.

The impact of BMI on survival in gastric cancer (GC) is not clear. We sought to explore the relationship between BMI and tumor site, clinicopathologic characteristics, postoperative complications, and prognosis in GC patients. Patients who underwent gastrectomy for GC between January 2011 and June 2016 formed the study cohort (n = 827). Patients were divided into three groups according to the BMI (in kg/m²): "low" (<18.5), "normal" (18.5-24.9), and "high" (≥25.0). The preoperative level of albumin and hemoglobin in the low BMI group was lower than that in the high BMI or normal BMI group (P < 0.05). The prevalence of gastric-cardia cancer in the high BMI group was significantly higher than that in the low BMI group (P = 0.001). The prevalence of gastric-antrum cancer in the high BMI group was significantly lower than that in the low BMI group (P = 0.001) and the normal BMI group (P = 0.004). The BMI of patients with gastric-cardia cancer was significantly higher than that of patients with gastric-body cancer (P = 0.018) and gastric-antrum cancer (P < 0.001). There were no significant differences among the three groups in terms of tumor size, TNM stage, depth of tumor invasion, degree of tumor differentiation, resection margin, lymph node metastasis, or postoperative complications. BMI was not an independent factor that influenced the prognosis. We found a relationship between BMI and GC site. A low BMI may be associated with a poor prognosis and a high BMI may be related to a favorable prognosis. BMI was not an independent factor that influenced GC prognosis.