Laparoscopic Colectomy: A Risk Factor for Postoperative Peritoneal Metastasis

The oncologic outcomes are generally considered equivalent for both laparoscopic and open surgery. However, our previous single-center study found a greater risk of postoperative peritoneal metastasis (PM) after laparoscopic colectomy (LC) than after open colectomy (OC) in patients with pathological T4a (pT4a) colon cancer. This multicenter study aimed to clarify if the risk of PM was increased after LC.This study used the multicenter database of the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer, which included patients with colorectal cancer treated between 1997 and 2012 in 24 referral hospitals across Japan. The analysis included 17,323 patients with pathological stage I-III colon cancer, including 2380 patients with pT4a disease. The risk of PM was compared between the LC and OC groups.The cumulative incidence of PM was significantly higher after LC in patients with pT4a colon cancer (13.0% vs. 7.7%; P = .001). Multivariable analyses showed LC was a significant risk factor for PM (hazard ratio [HR]: 1.36, 95% confidence interval [CI]: 1.04-1.78, P = .023), which was confirmed by propensity score analyses (HR: 1.36, 95% CI: 1.04-1.78, P = .024).This study demonstrated a significant increase in the risk of PM after LC than after OC.