Cancer cachexia is characterized by a process of involuntary catabolism that is associated with poorer outcomes such as decreased response to treatment, decreased functional status/quality of life, and shorter survival. The exact definition is debatable and the variability of classification criteria in the literature has limited the ability to compare results of individual clinical trials. As a result, this limits the advance of our knowledge on cancer cachexia, along with its routine clinical management. In an attempt to establish diagnostic criteria, a formal consensus process was established, proposing three possible definitions: 1. Weight loss >5% over past 6 months (in absence of simple starvation); 2. Body mass index (BMI) 2%; 3. Sarcopenia defined by lumbar skeletal muscle index determined by computerized tomography (CT) imaging (men 2%. Using baseline data from a clinical trial (n=547 patients with lung cancer), we investigated the use of these different diagnostic criteria and hypothesized that each criterion would result in a similar prevalence of cachexia. Demographic characteristics were used as well as CT images obtained as part of medical diagnosis. The prevalence of cachexia by each diagnostic criterion was approximately 47%, 8% and 41% for criterion 1, 2 and 3 respectively. Cachexia diagnosis was not consistent among the three classifications either. The recently proposed diagnostic criteria for cancer cachexia does not consistently identify individuals as having cancer cachexia which may have potential unfavorable implications to research and clinical practice.
