Laparoscopic versus open resection for stage II/III rectal cancer in obese patients: A multicenter propensity score-based analysis of short- and long-term outcomes.

Aim: Whether a laparoscopic procedure can contribute to the improvement of clinical outcomes in obese patients with stage II/III rectal cancer compared to an open procedure remains unclear.

Objective: This study evaluated the technical and oncological safety of laparoscopic surgery versus open surgery in obese patients (body mass index [BMI] ≥25 kg/m) with rectal cancer.

Patients And Methods: Data were collected from patients with pathological stage II/III rectal cancer and analyzed. Operations were performed via laparoscopic or open surgery from 2009 to 2013. A comparative analysis was performed after applying propensity score matching to the two cohorts (laparoscopic group and open group). The primary endpoint was 3-y relapse-free survival (RFS).

Results: Overall, 524 eligible cases were collected from 51 institutions. Equal numbers of propensity score-matched patients were included in the laparoscopic (n = 193) group and open (n = 193) group. Although the rate of D3 lymph node dissection did not differ between the laparoscopic group (87.0%) and the open group (88.6%), the median number of harvested lymph nodes was significantly lower in the laparoscopic group versus open group (17.5 vs 21,  = 0.0047). The median postoperative hospital stay was also significantly shorter in the laparoscopic group (14 d) vs the open group (17 d) ( = 0.0014). Three-y RFS was not significantly different between the two groups (hazard ratio 1.2454, 95% confidence interval 0.9201-1.6884,  = 0.4689).

Conclusion: The short- and long-term results of this large cohort study (UMIN ID: UMIN000033529) indicated that laparoscopic surgery in obese rectal cancer patients has advantageous short-term outcomes and no disadvantageous long-term outcomes.