Comparative analysis of the oncologic outcomes and risk factors for open conversion in laparoscopic surgery for non-metastatic colorectal cancer: A retrospective multicenter study

Purpose: Laparoscopic colon surgery is now commonly used for colorectal cancer (CRC) resection. The objective of this study was to compare the oncologic outcomes between open conversion and laparoscopic surgery, and to identify risk factors for open conversion.

Methods: We retrospectively reviewed the medical records of patients who underwent curative resection for stage 0-III CRC at five Hallym University-affiliated hospitals between January 2011 and June 2021. The patients were divided into the conversion and laparoscopic groups according to whether laparoscopic surgery was completed.

Results: Out of 2231 patients, laparoscopic surgery was completed in 2131 patients and 100 (4.5 %) converted to open surgery. The operation time (P = 0.028) and postoperative hospital stay (P = 0.036) were longer in the conversion group than in the laparoscopic group. Overall (P = 0.022) and severe (Clavien-Dindo classification grade ≥3) (P = 0.048) complications were more frequent in the conversion group than in the laparoscopic group. The 5-year recurrence-free survival (RFS) rate was worse in the conversion group than in the laparoscopic group (P = 0.002). In the multivariable analysis, open conversion was not a prognostic factor for RFS (P = 0.082). Abdominal surgery history (P = 0.021), obstruction (P < 0.001), and T4 stage (P < 0.001) were independently associated with open conversion.

Conclusion: The conversion group had worse perioperative and oncologic outcomes. History of abdominal surgery, obstruction, and T4 stage were associated with open conversion. However, conversion itself was not associated with RFS.