3518 Background: Laparoscopic surgery for rectal cancer has been used widely. However, recent two randomized trials raised concerns about short-term oncologic safety of laparoscopic surgery for rectal cancer. The aim of this study was to evaluate the long-term oncologic safety of laparoscopic surgery for rectal cancer based on 7-year data from the Comparison of Open versus laparoscopic surgery for mid or low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial. Methods: COREAN trial was a non-inferiority, randomized controlled trial. Between April, 2006, and Aug, 2009, eligible participants with mid or low rectal cancer treated with preoperative chemoradiotherapy were randomly assigned (1:1) to laparoscopic (n = 170) or open surgery (n = 170). Seven-year outcomes included overall and disease-free survival, and local recurrence. Log-rank test and stratified Cox regression analysis were used for survival analysis. Analysis was by intention to treat. Results: The median follow-up times were 84 months (IQR: 61.5-97.0). No differences were found between laparoscopic and open surgery group in terms of overall and disease-free survival, and local recurrence (7-year overall survival: 83.2% [laparoscopic] vs 77.3% [open], p = 0.48; 7-year disease-free survival: 71.6% [laparoscopic] vs 64.3% [open], p = 0.20; 7-year local recurrence: 3.3% [laparoscopic] vs 7.9% [open], p = 0.08). Stratified Cox regression analysis adjusted for ypT, ypN and tumor regression grade showed no significant difference between groups in terms of overall and disease-free survival, and local recurrence. The hazard ratios for overall survival, disease-free survival and local recurrence (open vs laparoscopic surgery) were 0.96 (95% CI = 0.58-1.57), 1.03 (95% CI = 0.70-1.53), and 2.28 (95% CI = 0.82-7.16), respectively. Conclusions: The 7-year analysis confirm the long-term oncological safety of laparoscopic surgery for rectal cancer treated with preoperative chemoradiotherapy. The use of laparoscopic surgery does not compromise the long-term survival outcomes in rectal cancer. Clinical trial information: NCT00470951.
Tumor Regression Grading After Preoperative Chemoradiotherapy as a Prognostic Factor and Individual-Level Surrogate for Disease-Free Survival in Rectal Cancer
