COLOR II: Laparoscopic Versus Open Rectal Cancer Removal

The design involves allocation of all suitable consecutive patients with rectal carcinoma to either of the two procedures at a randomization ratio of 2:1 in favor of the laparoscopic procedure. Excluded are patients with a carcinoma treated by local resection and palliative resections. The trial will be stratified according to participating centre, resection type, and preoperative radiotherapy. If the 95% CI for the difference of the 3-year locoregional recurrence rates excludes a difference greater than 5% in favor of the conventional procedure, non-inferiority of the laparoscopic procedure will be concluded. Assuming both rates are 10%, 1000 evaluable cases are required in total for a power of 80%. Analysis will be primarily on an intention to treat basis. Definition of conversion is defined by protocol.