Safety assessment of treatment with cetuximab in metastatic colorectal cancer patients

Study hypothesis: Observational study, recording skin toxicity of cetuximab according to the National Cancer Institute Common Toxicity Criteria (NCI CTC), version 3.0, and to determine the best management of skin toxicity of cetuximab Primary outcome(s): 1. Safety of treatment with cetuximab 2. Management of skin toxicity of cetuximab