Laparoscopic versus open colectomy for locally advanced T4 colonic cancer: meta-analysis of clinical and oncological outcomes

Background The aim of this study was to review the early postoperative and oncological outcomes after laparoscopic colectomy for T4 cancer compared with open surgery. Method MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched for any relevant clinical study comparing laparoscopic and open colectomy as treatment for T4 colonic cancer. The risk ratio (RR) with 95 per cent confidence interval was calculated for dichotomous variables, and the mean difference (MD) with 95 per cent confidence interval for continuous variables. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was implemented for assessing quality of evidence (QoE). Results Twenty-four observational studies (21 retrospective and 3 prospective cohort studies) were included, analysing a total of 18 123 patients: 9024 received laparoscopic colectomy and 9099 underwent open surgery. Laparoscopic colectomy was associated with lower rates of mortality (RR 0.48, 95 per cent c.i. 0.41 to 0.56; P < 0.001; I-2 = 0 per cent, fixed-effect model; QoE moderate) and complications (RR 0.61, 0.49 to 0.76; P < 0.001; I-2 = 20 per cent, random-effects model; QoE very low) compared with an open procedure. No differences in R0 resection rate (RR 1.01, 1.00 to 1.03; P = 0.12; I-2 = 37 per cent, random-effects model; QoE very low) and recurrence rate (RR 0.98, 0.84 to 1.14; P = 0.81; I-2 = 0 per cent, fixed-effect model; QoE very low) were found. Conclusion Laparoscopic colectomy for T4 colonic cancer is safe, and is associated with better clinical outcomes than open surgery and similar oncological outcomes. Advantages of the laparoscopic technique for patients with pT4 colonic cancer in terms of mortality, postoperative morbidity, and Clavien-Dindo grade III-IV complication have been shown in the present meta-analysis, with an overall low quality of evidence. The absence of a statistically significant difference in surgical radicality, including R0 curative resection, positive margin rates, and recurrence, although limited by low quality of evidence, confirmed the reliability of the laparoscopic technique from an oncological point of view. Together, these findings suggest that laparoscopic colectomy appears to be safe for selected pT4 colonic cancers, if performed in centres with expertise in minimally invasive colorectal surgery. Lay Summary Colonic cancer accounts for 9.4 and 10.6 per cent of all tumours in women and men respectively. Approximately 10-20 per cent of patients diagnosed with colonic cancer present with locally advanced tumours that have grown beyond the bowel wall or invade other organs. This study aimed to review the currently available evidence for laparoscopic (minimally invasive surgery or keyhole surgery) colonic cancer surgery for locally advanced tumours, with particular emphasis on the early postoperative and long-term oncological outcomes after laparoscopic colectomy, and to compare this with conventional open surgery. Medical databases were searched for publications of comparative studies, including RCTs (a clinical study in which participants are randomly allocated to treatment groups), prospective cohort studies, and retrospective cohort studies (clinical studies in which participants are not randomly allocated to treatment groups) comparing laparoscopic and open surgery as a treatment for locally advanced colonic cancers. The searches were up to date to April 2021. Twenty-four comparative, non-randomized studies were included, analysing a total of 18 123 patients: 9024 received laparoscopic colonic resection and 9099 underwent open surgery. Laparoscopic resection was associated with lower rates of postoperative mortality and complications compared with open surgery. No significant difference in the radicality of the surgical operation and cancer recurrence rate was found. In addition, no significant differences were found between the two interventions regarding 3-year disease-free survival (patient survives without any signs or symptoms of colonic cancer) and 5-year disease-free survival. Advantages in terms of lower rates of mortality and complications of the laparoscopic compared with the open technique for patients with locally advanced colonic cancer have been shown in this study.