Impact of obesity on perioperative outcomes and survival following pancreaticoduodenectomy for pancreatic cancer: A large single-institution study

Background: To examine the effect of body mass index (BMI) on clinicopathologic factors and long-term survival in patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma. Methods: Data on BMI, weight loss, operative details, surgical pathology, and long-term survival were collected on 795 patients who underwent pancreaticoduodenectomy. Patients were categorized as obese (BMI > 30 kg/m²), overweight (BMI 25 to <30 kg/m²), or normal weight (BMI < 25 kg/m²) and compared using univariate and multivariate analyses. Results: At the time of surgery, 14% of patients were obese, 33% overweight, and 53% normal weight. Overall, 32% of patients had preoperative weight loss of >10%. There were no differences in operative times among the groups; however, higher BMI was associated with increased risk of blood loss (P < 0.001) and pancreatic fistula (P = 0.01). On pathologic analysis, BMI was not associated with tumor stage or number of lymph nodes harvested (both P > 0.05). Higher BMI patients had a lower incidence of a positive retroperitoneal/uncinate margin versus normal weight patients (P = 0.03). Perioperative morbidity and mortality were similar among the groups. Obese and overweight patients had better 5-year survival (22% and 22%, respectively) versus normal weight patients (15%; P = 0.02). After adjusting for other prognostic factors, as well as preoperative weight loss, higher BMI remained independently associated with improved cancer-specific survival (overweight: hazard ratio, 0.68; obese: hazard ratio, 0.72; both P < 0.05). Conclusion: Obese patients had similar tumor-specific characteristics, as well as perioperative outcomes, compared with normal weight patients. However, obese patients undergoing pancreaticoduodenectomy for pancreatic cancer had an improved long-term survival independent of known clinicopathologic factors.