Supplementary Material for: Safety and efficacy of laparoscopic surgery versus open surgery in elderly patients with colon cancer: a propensity score matching cohort study

Introduction: The safety of laparoscopic surgery (LS) and its effect on survival have not been sufficiently assessed in elderly colon cancer patients. Methods: Clinicopathologic data of patients aged ≥ 75 years who underwent colectomies for primary colon cancer, between January 2018 and June 2021, were reviewed. Patients were divided into LS and open surgery (OS) groups according to the intention-to-treat principle, and were compared using propensity score matching. The primary outcomes were differences in surgical safety and 3-year survival rates. Results: There were 98 patients with a median age of 82 years and 85 patients with a median age of 80 years, assigned to the OS and LS groups, respectively. Propensity score matching revealed that LS did not prolong the operation time (190 versus 180 min, P = 0.209), was linked to less intraoperative blood loss (50 versus 100 mL, P = 0.039) and shorter postoperative hospital stays (8 versus 10 days, P = 0.005), compared to OS. In addition, LS was not accompanied by more stress responses when the variations exhibited in laboratory tests and the Barthel index pre- and post- surgery were considered. There were no significant differences in the adjusted 3-year overall survival (86.0% versus 81.2%, P = 0.795) and disease-free survival (86.6% versus 87.9%, P = 0.356) rates between the groups. Conclusion: LS enhanced post-operative recovery without increasing surgical risks, compared to OS, in colon cancer patients aged ≥ 75 years. Furthermore, no significant differences in the 3-year adjusted survival rates were observed between the groups.