Oncologic outcomes of preoperative stent insertion first versus immediate surgery for obstructing left-sided colorectal cancer

Background: Colonic self-expanding metallic stenting (SEMS) is widely used for the treatment of malignant colonic obstruction as a bridge to elective surgery. However, the effects of colonic stenting on long-term oncologic outcomes are debatable. This study aimed to compare the long-term oncologic outcomes of preoperative SEMS insertion with those of immediate surgery in patients with obstructing left-sided colorectal cancer. Methods: A cohort of consecutive patients who underwent radical surgery for obstructing left-sided colorectal cancer between 2004 and 2011 in five tertiary referral hospitals were analyzed. Long-term survivals were analyzed and adjusted using the inverse probability of treatment weighting method, based on propensity scores, to reduce selection bias. Results: One hundred and nine patients underwent immediate surgery, and 226 underwent stent insertion before surgery. Disease-free survival did not differ significantly in both the unadjusted population (hazard ratio [HR] 1.063, 95% confidence interval [CI] 0.730-1.548; Log-rank, p=0.746) and the adjusted population (HR 0.122, 95% CI 0.920-1.987; Log-rank, p=0.122). Overall survival also did not differ significantly in both the unadjusted population (HR 0.871, 95% CI 0.568-1.334; Log-rank, p=0.526) and the adjusted population (HR 1.023, 95% CI 0.665-1.572; Log-rank, p=0.916). Defunctioning stoma formation was less in the SEMS insertion group than immediate surgery group (adjusted, 14.6% vs. 41.3%, p < 0.001). Conclusion: The 'bridge to surgery' strategy using metallic stents was oncologically comparable to immediate surgery in patients with malignant left-sided colorectal obstruction. (C) 2018 Elsevier Ltd. All rights reserved.