Laparoscopic versus open colectomy for locally advanced colon cancer in obese patients: a nationwide, multicenter, propensity score-based analysis of short- and long-term outcomes.

Objective: This study evaluated the short-and long-term outcomes of laparoscopic colectomy versus open surgery in obese patients (body mass index ≥25 kg/m2) with locally advanced colon cancer to ascertain the non-inferiority of laparoscopic surgery to open surgery.

Methods: In this large cohort study (UMIN-ID: UMIN000033529), we retrospectively reviewed prospectively collected data from consecutive patients who underwent laparoscopic or open surgery for pathological stage II-III colon cancer between 2009 and 2013. A comparative analysis was performed after propensity score matching between the laparoscopic and open surgery groups. The primary endpoint was the 3-year relapse-free survival (RFS).

Results: We identified 1575 eligible patients from 46 institutions. Each group comprised 526 propensity score-matched patients. Comparing the laparoscopic versus open surgery group, laparoscopic surgery was significantly associated with increased median operating time (225 vs. 192.5 min; P < .0001) and decreased median estimated blood loss (20 vs. 140 ml; P < .0001). Lymph node retrieval (20 vs. 19; P = 0.4392) and postoperative complications (4.6% vs. 5.7%; P = 0.4851) were similar, postoperative hospital stay was shorter (10 vs. 12 days; P < .0001), and the 3-year RFS rates were similar (82.8 vs. 81.2%). The hazard ratio (HR) for relapse-free survival for laparoscopic versus open surgery was 0.927 (90% confidence interval [CI], 0.747-1.150, one-sided P for non-inferiority = .001), indicating that for obese patients with colon cancer, laparoscopic surgery was non-inferior to open surgery.

Conclusion: Laparoscopic surgery in obese patients with colon cancer offers advantages in terms of short-term outcomes and no disadvantages in terms of long-term outcomes.