NEOadjuvant Chemotherapy Only Compared With Standard Treatment for Locally Advanced Rectal Cancer

Inclusion Criteria: * Adenocarcinoma of the rectum with the lower boarder within 15 cm from the anal verge * Locally advanced tumor based on imaging * T3 tumors within 10 cm from the anal verge fulfilling the criteria for preoperative radio-chemotherapy according to Danish Colorectal Cancer Group (DCCG) guidelines * T3c or T4 tumors 10-15 cm from the anal verge * Deemed resectable at the multidisciplinary team (MDT) conference * Eastern Cooperative Oncology Group (ECOG) performance status 0-2 * Age at least 18 years * Adequate bone marrow, liver and renal function allowing systemic chemotherapy * Absolute neutrophil count ≥1.5x109/l and thrombocytes ≥ 100x109/l. * Bilirubin ≤ 1.5 x upper normal value and alanine aminotransferase ≤ 3 x upper normal value * Calculated or measured renal glomerular filtration rate at least 30 mL/min * Anticonception for fertile women and for male patients with a fertile partner. Intrauterine device, vasectomy of a female subject's male partner or hormonal contraceptive are acceptable * Written and orally informed consent Exclusion Criteria: * Distant metastasis * Invasive ingrowth into other organs * Incapacity, frailty, disability and comorbidity to a degree that according to the investigator is not compatible with combination chemotherapy * Previous radiotherapy to the pelvis * Previous treatment with 5FU or oxaliplatin * Surgery within two weeks * Neuropathy NCI grade \> 1 * Other malignant tumor within 5 years except non-melanoma skin cancer or carcinoma in situ cervicis uteri * Pregnant (positive pregnancy test) or breast feeding women