Open versus laparoscopic surgery for mid or low rectal cancer after neoadjuvant chemoradiotherapy (COREAN trial): 10-year follow-up of an open-label, non-inferiority, randomised controlled trial

Laparoscopic surgery has been widely used for rectal cancer; however, its long-term outcomes remain controversial. This study aimed to assess the long-term oncological safety of laparoscopic surgery for rectal cancer using 10-year follow-up data of the Comparison of Open versus laparoscopic surgery for mid or low REctal cancer After Neoadjuvant chemoradiotherapy (COREAN) trial.The COREAN trial is a, open-label, non-inferiority, randomised controlled trial. Eligible participants were aged 18-80 years, had cT3N0-2M0 middle or low rectal cancer with lesions located within 9 cm of the anal verge, and had been treated with preoperative chemoradiotherapy. Patients were randomly assigned (1:1) to open or laparoscopic surgery with a computer-generated random allocation sequence with a random permuted block design. Neither patients nor clinicians were masked to treatment assignment. Open or laparoscopic total mesorectal excision was done 6-8 weeks after the administration of preoperative concurrent chemoradiotherapy (fluoropyrimidines alone, doublet therapy, or triplet therapy) at a dose of 50·5 Gy over 5·5 weeks. Postoperative adjuvant chemotherapy was administered for 4 months. The primary endpoint of 3-year disease-free survival was published previously. Here, we report 10-year overall survival, disease-free survival, and local recurrence. Analyses were done in the modified intention-to-treat population of all participants who were randomly assigned and provided follow-up data. This study is registered with ClinicalTrials.gov, NCT00470951.Of the 340 patients enrolled in the COREAN trial between April 4, 2006, and Aug 26, 2009 (170 patients in each group), two patients in the laparoscopic surgery group moved abroad and were lost to follow-up, so were not included in this 10-year analysis. The median duration of follow-up was 143 months (IQR 122-156). No differences were observed in 10-year overall survival (74·1% [95% CI 66·8-80·0] in the open surgery group vs 76·8% [69·6-82·5] in the laparoscopic surgery group; p=0·44), 10-year disease-free survival (59·3% [51·1-66·5] vs 64·3% [56·0-71·5]; p=0·20), or 10-year local recurrence (8·9% [5·2-15·0] vs 3·4% [1·4-7·9]; p=0·050) between the open surgery and laparoscopic surgery groups at 10 years after surgery. The stratified hazard ratios, adjusted for ypT and ypN classification and tumour regression grade, for open surgery versus laparoscopic surgery were 0·94 (95% CI 0·63-1·43) for overall survival, 1·05 (0·74-1·49) for disease-free survival, and 2·22 (0·78-6·34) for local recurrence.The 10-year follow-up of the COREAN trial confirms the long-term oncological safety of laparoscopic surgery in patients with rectal cancer treated with preoperative chemoradiotherapy. Similar to open surgery, laparoscopic surgery does not compromise long-term survival outcomes in rectal cancer when performed by well trained surgeons.National Cancer Center, Goyang, South Korea.