Consolidation Versus Induction Chemotherapy in Total Neoadjuvant Therapy of Rectal Cancer With High Risk for Recurrence

Inclusion Criteria:- histologically proven rectal adenocarcinoma * no distant metastases on CT scan (M0 disease) * at least one high risk factor for disease recurrence identified on MR imaging: * T4 tumor (cT4) * N2 disease (cN2) * extramural venous invasion (cEMVI+) * positive lateral lymph nodes * distance of tumor to mesorectal fascia or positive lymph nodes is 1 mm or less (cMRF+) * capacity for informed consent * willingness to attend regular check-ups during and after treatment Exclusion Criteria:history of previous irradiation in the pelvic area * absolute contraindications for MR imaging * distant metastases cannot be reliably excluded * synchronous cancer * chronic inflammatory bowel disease