COLOR III Trial: Transanal vs Laparoscopic TME

Background Surgery for mid and low rectal cancer is associated with relative high rates of incomplete mesorectal excisions and high rates of circumferential resection margin (CRM) involvement resulting in significant number of local recurrences. Moreover, patients with mid and low rectal cancer suffer from high rates of morbidity, permanent colostomies and impairment of quality of life. The transanal TME (TaTME) has been developed to improve the quality of TME surgery in mid and low rectal cancer. Study design The COLOR III trial is an international multicentre randomised study comparing short- and long-term outcomes of TaTME and laparoscopic TME for rectal cancer. The study will include a quality assessment phase before randomisation to ensure required competency level and uniformity of the new TaTME technique and the laparoscopic TME. During the trial clinical data will be reviewed centrally to ensure uniform quality. Endpoints The primary endpoint of the study is the local recurrence rate at 3-years follow-up. Secondary endpoints include sphincter saving procedures, short-term morbidity and mortality, involved circumferential resection margin (CRM), disease-free and overall survival at 3 and 5 years, completeness of mesorectum and quality of life. Statistics In laparoscopic TME the percentage of local recurrence at 3-years follow-up is estimated 5%. With the non-inferiority margin set at 4%, with a one-sided level of significance of 2.5% and a power of 80%, a total of 1104 patients is needed, 669 patients in the TaTME arm and 335 patients in the laparoscopic TME arm. All analyses will be performed on intention-to-treat basis. Main selection criteria Patients with histologically proven single mid or distal rectum carcinoma (0 to 10 cm from anal verge) at MRI, eligible for restorative surgery with a curative intent, are included. Patients with a T1 tumor suitable for local excision, T3 tumors with a suspected involved circumferential resection margin and T4 tum