340. THE IMPACT OF OBESITY ON SURGICAL OUTCOMES AFTER ESOPHAGECTOMY FOR CANCER IN SWEDEN

Abstract Background Global obesity rates continue to rise and are closely linked to an increase in esophageal adenocarcinoma. While obesity is associated with an increased risk of postoperative complications, its influence on long-term survival is less clear. Some studies suggest that obese patients have poorer outcomes due to higher comorbidity rates, while others indicate comparable or even better survival, possibly due to better nutritional reserves. This study aims to investigate whether obesity affects the survival and risk of postoperative complications in a national cohort of esophageal cancer patients. Methods This retrospective population-based register study included all individuals who underwent esophageal resection between 2006 and 2018 in Sweden. Data were extracted from the national quality registry for esophageal and gastric cancer (NREV). The cohort was grouped based on body mass index (BMI) into underweight (BMI < 20), normal (BMI 20-25), overweight (BMI 25-30), and obese (BMI > 30). Kaplan-Meier was used for survival analysis, and logistic regression and Cox regression were used for adjusted analyses (adjusting for sex, age, marital status, education level, Charlson comorbidity index score, histopathology, disease stage, and year of diagnosis). Results In total, 1742 individuals (79.9% males, mean age 66) were included, of whom 242 (13.9%) were obese. Obese individuals had more comorbidities at surgery, more commonly had adenocarcinoma, and underwent surgery more frequently in the later time period. The risk of surgical complications (e.g., anastomotic leak, bleeding) for obese individuals was not increased compared to those with normal weight (OR: 0.83 [0.56-1.21]), but an increased risk of non-surgical complications (e.g., pneumonia, cardiopulmonary events) was observed (OR: 1.78 [1.22-2.60]). The risk of death of any cause was decreased in obese individuals compared to those with normal weight (HR: 0.74 [0.58-0.95]), resulting in superior overall survival. Conclusion Despite the presence of more comorbidities among obese individuals undergoing esophagectomy, their risk of surgical complications remained comparable to those with normal weight. However, obese individuals exhibited a heightened susceptibility to other postoperative complications. Surprisingly, obese individuals demonstrated an improved overall survival at 5 years compared to those with normal weight.