RATIONALE: Monoclonal antibodies, such as cetuximab, can target tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Best supportive care is the use of drugs and other treatments to improve the quality of life of patients. Combining cetuximab with best supportive care may slow the growth of the tumor and help patients live longer and more comfortably. It is not yet known whether cetuximab combined with best supportive care is more effective than best supportive care alone in treating metastatic epidermal growth factor receptor-positive colorectal cancer.