Cancer cachexia is a systemic syndrome characterized by muscle loss, whose pathogenesis is triggered by tumour-induced inflammatory response and exacerbated by radio-chemotherapy. Consequently, appetite is disrupted and muscle protein catabolism is increased. Cachexia is clinically relevant since it increases morbidity and mortality. The effective treatment should be based on appropriate timing of nutritional support, modulation of inflammatory response and physical activity. Anti-cachexia drugs should also be integrated by nutritional support.