Rates of operative morbidity at 30 days, comparison between the two groups. Grade I Any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions Allowed therapeutic regimens are: drugs as antiemetics, antipyretics, analgetics, diuretics and electrolytes and physiotherapy. This grade also includes wound infections opened at the bedside.

Grade II Requiring pharmacological treatment with drugs other than such allowed for grade I complications.

Blood transfusionsand total parenteral nutritionare also included. Grade III Requiring surgical, endoscopic or radiological intervention

• IIIa Intervention not under general anesthesia
• IIIb Intervention under general anesthesia Grade IV Life-threatening complication (including CNS complications)* requiring IC/ICU-management
• IVa single organ dysfunction (including dialysis)
• IVb multiorgan dysfunction

Rates of operative mortality at 30 days, comparison between the two groups. Grade V Death of a patient

Quality of mesorectum resection assessed by TME completeness scale:

1. Mesorectal resection (MRR)/good/complete: intact mesorectum and smooth mesorectal surface with only minor irregularities; no defects deeper than 5 mm; no coning of the specimen towards the distal margin; and smooth macro-circular resection margin (CRM) on slicing.
2. Intramesorectal resection (IMR)/intermediate/nearly complete: intermediate bulk of the mesorectum with an irregular surface; a defect deeper than 5 mm, and no visible muscularis propria other than inserted levator; intermediate coning; intermediate irregularity of macro-CRM on slicing.
3. Muscularis propria resection (MPR)/poor/incomplete: small bulk of the mesorectum with a very irregular surface; defect down to the muscularis propria; severe coning; severe irregularity of macro-CRM on slicing.

Distant recurrence rates, comparison between the two groups

Local recurrence rates, comparison between the two groups

Overall survival rates, comparison between the two groups

Disease-free survival rates, comparison between the two groups

Radiotherapy related toxicity rates: skin reactions will be assessed using EORTC radiotherapy toxicity scale: Skin Grade 1 follicular, faint or dull erythema / epilation / dry desquamation / decreased sweating; Grade 2 tender or bright erythema, patchy moist desquamation / moderate edema; Grade 3 confluent, moist desquamation other than skin folds, pitting edema; Grade 4 - ulceration, hemorrhage, necrosis

Radiotherapy related toxicity rates: gastrointestinal reactions will be assessed using EORTC radiotherapy toxicity scale:

Grade 1 increased frequency or change in quality of bowel habits not requiring medication / rectal discomfort not requiring analgesics; Grade 2 diarrhea requiring parasympatholytic drugs (e.g. Lomotil) / mucous discharge not necessitating sanitary pads / rectal or abdominal pain requiring analgesics; Grade 3 diarrhea requiring parenteral support / severe mucous or blood discharge necessitating sanitary pads / abdominal distention (flat plate radiograph demonstrates distended bowel loops); Grade 4 acute or subacute obstruction, fistula or perforation; GI bleeding requiring transfusion; abdominal pain or tenesmus requiring tube decompression or bowel diversion

The Low anterior resection syndrome score (LARS) score consists of five items concerning the following: incontinence for flatus, incontinence for liquid stool, frequency of bowel movements, clustering of stools, and urgency. Each symptom of bowel dysfunction is weighed according to its impact on the quality of life. The calculated score ranges from 0 to 42, with a score of 0-20 representing no ARS, a score of 21-29 representing minor ARS, and a score of 30-42 representing major ARS.

We have assessed the immune response before chemoradiotherapy and 8 weeks following the treatment. IL1B, IL6, IL8, IL10, IL2R, TNF alfa are assessed and will be correlated with the response to treatment.

All the patients will have there urinary catheters removed on day 1. Some patients will get Urorec (adrenomimetic for prevention of urinary retention). The patients will be randomized 2:1