Cancer cachexia

### What you need to know Cancer cachexia is a complex syndrome characterised by tissue loss (fat, cardiac muscle, and skeletal muscle), decreased appetite (anorexia), fatigue, and reduced activity in patients with cancer (fig 1).1 It cannot be fully reversed with nutritional support alone and is caused by inflammation and metabolic dysfunction driven by the interaction between tumour and patient. Consequences include reduced efficacy of cancer treatment, poorer quality of life, and reduced survival.2 This article provides an update on cancer cachexia for healthcare professionals drawing on contemporary research and guidelines developed by the European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO). Fig 1 Characteristics of cancer cachexia ### What is controversial about cancer cachexia? The definition of cancer cachexia remains controversial. The role of inflammation is recognised as a key component; however, some argue that loss of skeletal muscle should be the defining feature. The first international consensus definition was published in 2011, and work is under way to update this. Lack of a clear consensus definition undermines the design of clinical trials. Rates of cancer cachexia vary across different cancer populations (fig 2), with both tumour site and tumour stage key determinants of prevalence. Cachexia is less common in patients with breast, prostate, and skin cancers.3456 Cancers most strongly associated with the syndrome include pancreatic, hepatobiliary, and oesophagogastric. Up to 80% of patients with these cancers are affected.7 Fig 2 Tumour sites most …