Key Points
➤ Cachexia is a multifactorial syndrome characterized by loss of
appetite, weight, and skeletal muscle leading to fatigue, functional
impairment, increased treatment-related toxicity, poor quality of life,
and reduced survival.
➤ Cachexia has been described as a weight loss in excess of 5% over
the preceding 6 months, or a body mass index (BMI) <20 kg/m
2
with
ongoing >2% weight loss, or depletion of muscle mass and >2%
weight loss.
➤ Multiple factors contribute to the complex pathophysiology of cancer
cachexia:
• Cancer profoundly alters the normal homeostatic control of energ y balance.
• Reduced food intake is an important and, in some cases, predominant component
of cancer-associated weight loss, and this results, in part, from altered hypothalamic
control of appetite and satiety.
• Uncontrolled symptoms of cancer or its treatments (e.g., pain, nausea, vomiting,
depression, dysgeusia) can, additionally, be detrimental to food intake.
• Aberrant metabolism is also implicated in cancer cachexia, distinguishing it from simple
malnutrition.
▶ The metabolic alterations may include neuro-hormonal dysregulation, elevated
energ y expenditure, and increased catabolism.
» Increased catabolic mediators are derived from tumor overexpression, and
inflammation elicited by a cancer can generate catabolic pro-inflammatory
cytokines and eicosanoids.
