Oncological outcomes of laparoscopic versus open surgery in pT4 colon cancers: A systematic review and meta-analysis

Background: Widespread adoption of minimally invasive surgery for colon cancer has achieved improved shortp-term benefits and better long-term oncological outcomes compared with open surgery. However, it is still controversial whether laparoscopic surgery is suitable for patients with stage T4 colon cancer. The aim of this meta-analysis was to compare short-and long-term oncological outcomes associated with laparoscopic and conventional open surgery for pT4 colon cancer. Methods: Published studies from 2003 to 2018 comparing oncological outcomes following laparoscopic and open surgery for pT4 colon cancer were systematically searched. Data on conversion rate, R0 resection rate, number of harvested lymph nodes, morbidity and mortality, and overall survival (OS) and disease-free survival (DFS) were subjected to meta-analysis using fixed-effect and random-effect models. Results: Twelve observational studies met the inclusion criteria with a total of 2396 cases (1250 laparoscopic and 1146 open). There was no significant difference in R0 resection rate [relative risk (RR) = 1.007; 95% confidence interval (CI) = 0.935-1.085; P = 0.850], number of harvested lymph nodes (MD = 0.004; 95% CI = -0.139 to 0.148; P = 0.951), mortality (RR = 0.509; 95% CI = 0.176-1.470; P = 0.212), and 3-year OS (RR = 1.056; 95% CI = 0.939-1.188; P = 0.360), 5-year OS (RR = 1.003; 95% CI = 0.883-1.139; P = 0.966), 3-year DFS (RR = 1.032; 95% CI = 0.903-1.179; P = 0.642), and 5-year DFS (RR = 0.995; 95% CI = 0.868-1.140; P = 0.973) between the groups. The rate of conversion from laparoscopic to open procedures was 10.7% (95% CI = 0.090-0.124). There was a significant difference in incidence of complications within 30 postoperative days between laparoscopic and open surgery (RR = 0.703; 95% CI = 0.564-0.876; P = 0.002). Conclusion: Laparoscopic surgery is safe and feasible in pT4 colon cancer, oncological outcomes are similar, and more importantly, there are fewer postoperative complications compared with open surgery.