Postoperative body mass index and the risk of unfavorable outcomes in adults following esophagectomy for esophageal cancer: A retrospective cohort study

Background Esophagectomy is an invasive procedure, frequently complicated by long‐term weight loss and nutritional deficiencies. Although outpatient nutritional support is recommended, specific target body mass index (BMI) has not been established. Accordingly, we aimed to identify the threshold of postoperative BMI associated with unfavorable outcomes following esophagectomy. Methods We analyzed 317 patients who underwent minimally invasive esophagectomy for esophageal cancer, measuring their postoperative BMI at 3, 6, and 12 months. Unfavorable outcomes were defined as a composite of mortality, unplanned readmission, or pneumonia requiring outpatient treatment. Restricted cubic spline models were employed to determine the BMI threshold, and multivariable generalized estimating equation logistic regression was used to examine the significance of the threshold on unfavorable outcomes. Results The median preoperative BMI was 21.6 kg/m 2 , which decreased to 18.7 kg/m 2 at 12 months. The BMI threshold was determined to be 19.5 kg/m 2 via restricted cubic spline analysis. Multivariable generalized estimating equation logistic regression confirmed that a BMI <19.5 kg/m 2 was significantly associated with a higher risk of unfavorable outcomes at 3 months (odds ratio: 2.29; P = 0.02), 6 months (odds ratio: 2.27; P = 0.03), and 12 months (odds ratio: 2.89; P = 0.009). Conclusion A BMI of 19.5 kg/m 2 could serve as a clinically relevant reference point for postoperative recovery. Maintaining a BMI above this threshold may be the primary goal of outpatient nutritional management to reduce unfavorable outcomes after esophagectomy.