Effect of Body Mass Index on Short-term Outcomes of Patients Undergoing Laparoscopic Resection for Colorectal Cancer: A Single Institution Experience in Japan

Background: The impact of body mass index (BMI) on laparoscopic surgery for colorectal cancer in Asian countries is unclear, partly because obesity is less common in Asia than in western countries. The purpose of this study was to evaluate the association between BMI and short-term outcomes after laparoscopic resection for colorectal cancer in Japanese patients. Methods: A cohort of 1194 patients who underwent laparoscopic resection for colorectal cancer at Cancer Institute Hospital between July 2005 and February 2010 were enrolled in this prospective study. Outcomes were analyzed according to BMI category: nonobese (BMI < 25), obese I (25 <= BMI < 30), and obese II (BMI >= 30). Results: A total of 926 patients (78%) were classified as nonobese, 243 (20%) were obese I, and 25 (2%) were obese II. Mean operating time (214 min vs. 244 min vs. 293min) and mean estimated blood loss (23mL vs. 42mL vs. 88mL) increased significantly with increasing BMI (P < 0.0001, respectively). The rate of postoperative complications was significantly higher in obese II patients than in nonobese and obese I patients (24% vs. 9.2% vs. 9.1%, P = 0.0428). Multivariate analysis showed that a BMI in the obese II range was an independent predictive factor for developing anastomotic leakage (odds ratio: 10.27, 95% confidence interval, 1.98-53.44). Conclusions: Laparoscopic surgery for colorectal cancer is technically more demanding in Japanese obese II patients than in nonobese or obese I patients. Special care is required because of the increased risk of developing postoperative complications.