Risk of peritoneal recurrence after laparoscopic versus open surgery for pT4 colon cancer. A propensity score-matched analysis from an international cohort

Background: Peritoneal carcinomatosis (PC) is an uncommon site of recurrence for colon cancer (CC), but it strongly affects prognosis with poor survival after diagnosis. Since no standard treatment has been established yet, efforts should be addressed towards the prevention of its occurrence. In particular, some literature suggested a detrimental effect of laparoscopic surgery in case of pT4 CC. This study aimed to determine the impact of laparoscopy on the development of PC after potentially curative resection for pT4 CC. Materials and Methods: This was an international multicentre retrospective cohort study that analysed patients from 5 tertiary referral centres. 276 cases fulfilled the inclusion criteria and were selected for analysis. After 1:1 propensity score matching (PSM), 63 patients in the laparoscopic group (LapGroup) were compared with 63 patients in the open surgery group (OpenGroup). Results: After PSM, the two groups were comparable for demographic and clinical parameters. Operative data as well as specimen characteristics did not differ between surgical approach. OpenGroup presented a higher estimated intraoperative blood loss (P < 0.001) and post-operative length of stay (P < 0.001). Overall survival, cancer-specific survival, and disease-free survival resulted to be comparable between groups. The 5-year probability of developing PC was 16.2 per cent after laparoscopic surgery and 19.5 per cent after open surgery (P = 0.686). Multivariate analysis confirmed laparoscopy not to be an independent risk factor for PC. Conclusions: Elective laparoscopic surgery for pT4 CC does not increase the risk of metachronous PC after potentially curative surgery. Moreover, long term outcomes are not inferior to conventional open resections.