Obesity and outcomes after esophagectomy: A nationwide population-based cohort study

The global prevalence of obesity is rising and has been linked to increased perioperative risks in esophageal cancer surgery, while its impact on long-term survival remains uncertain. This study aims to examine the association between body mass index (BMI, kg/m²) and perioperative complications and long-term survival.

This nationwide, population-based cohort study included all patients undergoing esophageal cancer resection in Sweden between 2006 and 2018. Data were obtained from the National Register for Esophageal and Gastric Cancer. Patients were categorized by BMI as underweight (<20), normal (20-24.9), overweight (25-30), or obese (>30). Logistic regression and Cox regression were used for adjusted analyses, reporting odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs).

A total of 1494 patients (81.6% male) were included, and out of these, there were 227 (15.2%) patients with obesity. Patients with obesity had more comorbidities, more often adenocarcinoma, and underwent surgery more frequently during the later time period of the study. Compared with patients with normal weight, obesity was not associated with increased risk of surgical complications (OR = 0.92, 95% CI: 0.62-1.39), but obesity was linked to higher risk of non-surgical complications, including pulmonary embolism (OR = 1.64, 95% CI: 1.10-2.45). Obesity was associated with reduced all-cause mortality (HR = 0.75, 95% CI: 0.57-0.98).

Patients with obesity undergoing esophagectomy did not have higher rates of surgical complications but faced an elevated risk of non-surgical complications. Obesity appeared linked to better long-term survival. However, residual confounding, including potential reverse causation from pre-diagnosis weight loss, cannot be excluded.