To improve oncological and functional outcomes of patients with rectal cancer new techniques are being developed. Traditional abdominal laparoscopic resection of low rectal cancer remains challenging with a relative high risk of irradicality.

The introduction of transanal single port surgery has led to the transanal total mesorectal excision (TaTME) technique. The rectum including the total mesorectum is mobilized transanally in a reversed way with minimally invasive surgery. The TaTME technique for low and mid rectal cancer has potential benefits: better specimen quality with better radicality, less morbidity as result of avoiding extraction wounds in the majority of patients and more sphincter saving rectal resections without compromising oncological outcomes.

Currently, cohort series have demonstrated potential benefits of the TaTME for rectal cancer including a low morbidity rate and a high rate of sphincter saving procedures. The COLOR and COLOR II study group have conducted multicenter and international
trials including over 2000 patients and demonstrated the benefit of laparoscopic colonic and rectal cancer surgery.

Our goal is to evaluate the TaTME technique compared to conventional laparoscopic rectal resection for patients with mid and low rectal cancer in an international randomized trial: the COLOR III trial. We aim to conduct a high quality trial, with high standards of imaging, surgery, pathology and follow-up with frequent auditing.