Minimal Invasive Treatment for Patients With Good Response to Chemoradiation With Selection and Follow-up by MRI: a Single Arm Phase-II Feasibility Study in Rectal Cancer

The high proportion of complete and good responders with modern chemoradiation and the improvement in magnetic resonance (MR)-imaging techniques have stimulated a renewed interest to the question whether in patients with complete or good response the overall benefits of a 'wait-and-see policy' or transanal endoscopic microsurgery (TEM) combined with intensive follow-up may outweigh the benefits associated with conventional surgery (total mesorectal excision (TME) or abdominoperineal resection (APR)). On the one hand, less invasive strategies will expose subjects to more diagnostic procedures and possibly a slightly higher risk of local failure and the need for salvage surgery. On the other hand, mortality and morbidity associated with radical surgery (e.g. anastomotic leakage, relaparotomy, wound and pelvic infection, chronic wound healing disturbances, abscess, colostomy, faecal or urinary incontinence and sexual dysfunction) can be avoided. The investigators believe that wait-and-see policy for complete responders and TEM for good responders after chemoradiation is a feasible alternative to standard surgery, provided these patients are intensively followed.