The Impact of Obesity on Operative Outcomes and Long-Term Oncological Outcomes Following Rectal Cancer Surgery: A Retrospective Single-Center Study.

Background: Our aim was to evaluate the impact of obesity on operative and long-term oncological outcomes following rectal cancer surgery. Methods: Single-center retrospective review of all patients that underwent rectal resection for primary rectal adenocarcinoma between 2010 and2020. Divided into two groups based on preoperative body mass index (BMI): obese-BMI ≥ 30 kg/m2, non-obese-BMI < 30 kg/m2. Results: Total of 513 patients included 100 in the obese group (mean BMI 33.5 kg/m2, range 30-45.6) and 413 in the non-obese group (mean BMI 24.9 kg/m2, range 15.6-29.9, p < 0.001). The groups exhibited a similar age distribution (63.94 and 63.23, p = 0.59) or gender distribution (p = 0.83) between the groups. The obese group had higher conversion rates to open approach (22% versus 11.6%, p = 0.007), and longer surgeries (median 300 min, versus 260 min, p = 0.003), but similar overall postoperative complications (73% versus 64.4%, p = 0.1), 30-day readmission (19% versus 17.4%, p = 0.71), harvested lymph nodes (16 versus 14, p = 0.38), incidence of positive resection margins, 5-year overall survival (94.2% versus 88.7%, p = 0.97), and 5-year disease-free survival (70.4% versus 72%, p = 0.59). Conclusions: Obesity did not affect immediate overall surgical outcomes, surgical pathology quality indexes or long-term oncological outcomes.