Main outcome: Assess the impact of cancer-related survival at 2 years in patients with unresectable metastatic colorectal cancer treated with chemotherapy alone versus surgery followed by chemotherapy. To assess overall survival. To evaluate postoperative morbidity and mortality in patients treated with resection of the primary tumor. Assess complications and meed for surgery in patients treated with systemic chemotherapy only during the course of the disease. Identify and describe the complications related to chemotherapy and toxicity in the short and medium term systemic treatment. Assessing the quality of life questionnaire QLQ-C30 and QLQ-CR29. To study prognostic survival factors.