Long-term Oncologic Outcomes of Obesity after Laparoscopic Surgery for Colorectal Cancer in Asian Patients

ABSTRACT

PURPOSE: The adverse effects of obesity on short-term surgical outcomes after laparoscopic colorectal surgery have been reported. However, the influence of obesity on long-term oncological outcomes after laparoscopic surgery in Asian patients has not been well understood. The aim of this study was to evaluate the effect of obesity on long-term oncologic outcomes in patients who underwent laparoscopic surgery for colorectal cancer. METHODS: Overall, 424 consecutive patients who underwent laparoscopic resection for colorectal cancer between January 2005 and July 2012 were included in this retrospective study. Patients were classified as non-obese (body mass index [BMI] <25.0 kg/m²) and obese (BMI ≥25.0 kg/m²) according to the categories proposed by the International Obesity Task Force. A survival analysis was performed using clinicopathologic characteristics, including obesity. RESULTS: Of the 424 patients, 325 (76.7%) were classified as non-obese and 99 (23.3%) as obese. The clinicopathologic characteristics of the obese and non-obese groups were similar, except that there were more underlying comorbidities, a lower frequency of smoking, and fewer tumors in rectum in the obese group. Results of the multivariate analysis showed that older age, elevated serum carcinoembryonic antigen, high-grade histology, advanced tumor stage, and perineural invasion were associated with poorer disease-free survival and overall survival. Obesity was not significantly associated with disease-free survival (hazard ratio [HR], 1.196; 95% confidence interval [CI], 0.686~2.086; p=0.528) or overall survival (HR, 1.156; 95% CI, 0.584~2.289; p=0.677). CONCLUSION: Laparoscopic surgery for colorectal cancer seems to be safe and feasible for obese patients in terms of long-term oncologic outcomes.