Supplementary Material for: Outcomes of patients with left-sided obstructive colorectal cancer: Comparison between self-expandable metallic stent and other treatment methods

Introduction: The aim of this multi-institutional retrospective study was to evaluate the efficacy of preoperative self-expandable metallic stent (SEMS) placement for patients with left-sided obstructive colorectal cancer (OCRC). Methods: A total of 520 consecutive patients who received treatment for OCRC were enrolled. Of these patients, the data of 253 patients who underwent primary tumour resection for left-sided OCRC were reviewed. The short- and long-term outcomes were compared between the SEMS group and other three groups: transanal decompressive tube (TaDT), decompressive stoma (DS), and emergency resection (ER). Results: The SEMS group had a higher frequency of laparoscopic surgery (P <0.001), lesser frequency of postoperative stoma (P <0.001), and more dissected lymph nodes (P <0.001) than that of other groups. Moreover, the SEMS group had shorter postoperative hospital stays than that of TaDT and ER groups (P = 0.005 and P <0.001, respectively). The Kaplan-Meier survival curves of recurrence-free survival and overall survival did not differ significantly between the SEMS group and the other three groups in patients with stage II and III diseases. Discussion/Conclusion: Elective surgery after SEMS placement may improve short-term outcomes compared to other treatment strategies, with similar long-term outcomes.