Table 1 Study parameters and baseline characteristics that are collected in this study

Patients characteristics

gender, age at surgery—American Society of Anaesthesiologists (ASA) score—all co-morbidities—patient history (previous surgery, smoking status, allergies and current medications)—preoperative weight loss at 3 and 6 months before presentation (SNAQ score)—bodyweight at hospital presentation – height (centimetres)—bodyweight before surgery—blood pressure—nutritional risk (NRS)—concomitant and previous therapy (chemotherapy/radiation)—early warning score (EWS)

Laboratory values

sedimentation—C-reactive protein (CRP)—haemoglobin (Hb)—haematocrit (Ht) – leukocytes—prothrombin time (PTT)—renal function (sodium, potassium, glomerular filtration rate)—liver function (albumin, bilirubin, Alanine-Amino-Transferase (ASAT), Aspartate-Amino -transferase (ALAT), lactic acid dehydrogenase (LDH), alkaline phosphatase and gamma-GT) – creatinekinase -phosphate – lactate – vitamin D

Tumour characteristics

cancer stage (clinical and pathological) according to the tumour node metastasis (TNM) classification of the American Joint Committee – localization – metastases—endoscopic surveillance—tumour type – obstruction – pre-operative diagnostics (endoscopy, CT-scan, MRI, X-ray)

Surgical characteristics

surgical intervention—time till surgery (days)—pre-operative antibiotics—type of resection—laparoscopic/open procedure—diverting- or end colostomy—blood loss during surgery—operating time –oncological/gastrointestinal surgeon – time of surgery (day/night) – conversion – bowel distention operatively – serosa tears

During hospitalization

Nutrition (TPN/extra nutrition) – consultation of other specialist – pre-operative interventions (ultrasound, radiological interventions, medication needed) – weight gain – laboratory values – substantiation and decision for operation date

Post-operative

Intensive care surveillance – time nasogastric tube – time till bowel passage – complications (following Clavien-Dindo classification) – adjuvant treatment – hospitalisation days – interventions – radiology images

Follow up (3/6/912 months)

X-thorax – CEA – ultrasound of the liver – additional analysis if needed – weight loss/gain – metastasis – recurrence – endoscopy at 1 year FU