Inclusion Criteria:  Patients with histologically proven metastatic colorectal cancer (stage IV) at time of inclusion (patients with metastatic disease and potential curative treatment intention are allowed) Age ≥ 18 years Planned first systemic therapy for metastatic disease  Signed and dated informed consent form  Patients participating in the PRO module: prior to or at start of first systemic treatment for mCRC Patients not participating in the PRO module: within four weeks after start of fist systemic therapy for mCRC  Exclusion Criteria:  Patient who do not receive any systemic therapy for mCRC Patients whose metastatic disease was surgically resected prior to inclusion and who start adjuvant chemotherapy