Does conversion affect short-term and oncologic outcomes after laparoscopy for colorectal cancer?

Background Conversion of laparoscopic colorectal resection (LCR) for cancer has been associated with adverse short-term and oncologic outcomes. However, most studies have had small sample sizes and short followup periods. This study aimed to evaluate the impact of conversion to open surgery on early postoperative outcomes and survival among patients undergoing LCR for nonmetastatic colorectal cancer. Methods A prospective database of consecutive LCRs for nonmetastatic colorectal cancer was reviewed. Patients who required conversion (CONV group) were compared with those who had completed laparoscopic resection (LAP group). Only patients with a minimum 5-year follow-up period were included in the oncologic analysis. Kaplan– Meier curves were compared to analyze survival. A multivariate analysis was performed to identify predictors of poor survival. Results The conversion rate was 10.9 %. The most common reason for conversion was a locally advanced tumor (48.4 %). Conversion was associated with a significantly longer operative time and a greater blood loss. No differences were observed in terms of postoperative morbidity, mortality, or hospital stay between the CONV and LAP patients. During a median follow-up period of 120 months (range, 60–180 months), the CONV group had a significantly worse 5-year overall survival (OS) (79.4 vs 87.4 %; p = 0.016) and disease-free survival (DFS) (65.4 vs 79.6 %; p = 0.013). Univariate analysis showed that conversion to open surgery, postoperative complications, anastomotic leakage, pT4 cancer, stage 3 disease, and adjuvant chemotherapy were significant risk factors for OS and DFS. On multivariate analysis, pT4 cancer and a lymph node ratio (LNR) of 0.25 or greater were the only independent predictors of DFS and OS, whereas a LNR of 0.01 to 0.24 showed a trend that did not reach statistical significance. Conclusion Conversion to open surgery per se is not associated with worse early postoperative outcomes and does not adversely affect long-term survival per se.