Mucinous carcinoma is a predictive factor for the risk of open conversion from laparoscopic colectomy in colorectal cancer

laparoscopic is widely in the of colorectal conversion to open surgery is associated with the rate of unfavorable outcomes. The aim of this study was to determine the factors associated with open conversion from laparoscopic surgery for colorectal cancer. Methods: A total of 3,002 patients who underwent laparoscopic colectomy as an initial plan for the treatment of colorectal cancer located from the sigmoid colon to the rectum were retrospectively evaluated between January 2009 and December 2018 at Samsung Medical Center in Korea. Risk factors significantly associated with open conversion were determined using univariate and multivariate regression models. Results: Among the 3,002 patients, open conversion was performed in 120 patients (4%). Age >60 years (adjusted odds ratio [AOR], 2.370), preoperative bowel obstruction (AOR, 2.348), clinical T4 stage (AOR, 2.201), and serum carcinoembryonic antigen level >5 ng/mL (AOR, 2.289) were significantly associated with open conversion. Moreover, mucinous carcinoma was a significantly more frequent histopathologic type than adenocarcinoma (10.0% vs. 3.2%, P<0.001) in the open conversion group with an AOR of 2.549 (confidence interval, 1.259–5.159; P=0.009). Conclusion: The present study presented a novel finding, i.e. mucinous carcinoma as the histopathologic type could be an independent predictive factor for conversion from laparoscopic colectomy to open surgery. Identifying patients with mucinous carcinoma will help stratify the risk of open conversion preoperatively.