What's next in using CT scans to better understand cachexia?

Purpose of review Cachexia (CAX), a protein metabolism disorder commonly associated with cancer, can be evaluated by computed tomography (CT) scan assessment of skeletal muscle mass (SMM), a parameter associated with patient outcome. This review analyzes current barriers for using CT scans of SMM in routine management for defining prognostic risk groups, and proposes new areas of research to reach a better understanding of CAX mechanisms. Recent findings Current research is focused on establishing a robust and relevant CAX staging system to reach a consensual definition. Previous biomarkers of CAX are poorly associated with outcome and do not exhibit clinical benefit. Systemic inflammatory marker, decrease in intake assessments, and/or nonnutritional criteria have been integrated to develop a multidimensional, highly complex CAX signature and CAX staging. Summary A standardized definition of sarcopenia is essential, and its value in clinical practice should be evaluated in prospective interventional studies using skeletal muscle assessment. SMM loss may be a key element in defining early protein disorders occurring before weight loss and could be used as a trigger for initiating early nutritional support. Changes in SMM and body composition during follow- up are useful tools for exploring CAX mechanisms in terms of intrinsic factors or tumor evolution.