Anatomical Resection of Liver MetAstases iN patIents With RAS-mutated Colorectal Cancer

Time from operation date to date of disease recurrence in the liver, followed up at intervals of three months for a maximum duration of 24 months or until death. Any new, solid lesion in the liver after resection of all CRLM that fulfils imaging criteria (CT, MRI) of a metastasis is counted as an iDFS event.

Intraoperative blood loss presents the amount of blood lost from skin incision until skin closure. Spilling water and ascites will be subtracted. Swabs will be squeezed and their content will also be sucked and added to the fluid collected in the suction containers.

Time from skin incision until placement of last skin staple/suture.

Administration of blood transfusions is documented for the intra- and postoperative period within 48 hours postoperatively.

Postoperative day 1 until day of discharge

Days on the intermediate care unit (IMC) or intensive care unit (ICU) after surgery. Patient's stay in the recovery room exceeding 24 hours is counted as ICU stay

Frequency of peri-operative complications after resection of the primary tumor

Kind of peri-operative complications after resection of the primary tumor

Death due to any cause within 90 days after surgery

Platelet count will be measured preoperatively and on postoperative day 5

Levels of alanine-aminotransferase (ALT) will be measured preoperatively and on postoperative day 5

Levels of aspartate-aminotransferase (AST) will be measured preoperatively and on postoperative day 5

Levels of Gamma-glutamyl transferase (GGT) will be measured preoperatively and on postoperative day 5

Levels of international normalized ratio (INR) will be measured preoperatively and on postoperative day 5

Levels of total bilirubin will be measured preoperatively and on postoperative day 5

Levels of albumin will be measured preoperatively and on postoperative day 5

Invasive re-interventions such as placement of interventional drains, Endoscopic retrograde cholangiopancreatography (ERCP) with stent placement, chest tube placement, and re-laparotomy within 30 days after the index operation or during patients' initial hospital stay

Invasive re-interventions such as placement of interventional drains, Endoscopic retrograde cholangiopancreatography (ERCP) with stent placement, chest tube placement, and re-laparotomy within 30 days after the index operation or during patients' initial hospital stay

Detection of tumor at the resection margin will be counted as positive resection margin

The overall survival of all patients is assessed between operation date to date of death of any cause

The cancer-specific survival of all patients is assessed between operation date to date of death of colorectal cancer

The disease-free survival of all patients is assessed from operation date to the date of either progressive or recurrent disease, or death of any cause

Adjuvant therapy is not recommended. However, the decision for adjuvant therapy is left at discretion of the local oncologist. The administration of adjuvant therapy and kind of chemotherapy protocols used will be documented for both groups.

Frequency of interventions for treatment of intra- and/or extrahepatic disease recurrence will be documented. These interventions include: Chemotherapy, Surgical resection, Local ablation (e.g. radiofrequency or microwave ablation, stereotactic irradiation), Selective internal radiotherapy (SIRT), other

Kind of interventions for treatment of intra- and/or extrahepatic disease recurrence will be documented. These interventions include: Chemotherapy, Surgical resection, Local ablation (e.g. radiofrequency or microwave ablation, stereotactic irradiation), Selective internal radiotherapy (SIRT), other

Quality of life is measured preoperatively and at 90 days (± 7 days) and 12 months (± 7 days) postoperatively using the EORTC QLQ-C30 questionnaire (European Organisation for Research and Treatment of Cancer; Questionnaire for the assessment of Quality of Life of Cancer patients with the module dedicated to colorectal liver metastases (EORTC QLQ-LMC21); the questionnaire assesses multi-item scales, each item scoring from 1 to 4, a high score represents a high level of symptomatology or problems.