The metabolic response to cancer.

The syndrome of cachexia is characterized by anorexia and profound losses of host tissues and constitutes one of the most common paraneoplastic conditions seen with cancer. Furthermore, cachexia is associated with a considerable mortality and morbidity but its origin is still obscure and cachexia remains a multi-factorial problem. A better understanding of the cause of the cachectic process and a reversal of its deleterious effects would improve not only the quality of life, but also life expectancy for the cancer patient. Weight loss occurs as a consequence of increased energy expenditure and a failure to compensate for this increased energy demand; weight loss is also aggravated by a cancer-associated anorexia. The mechanisms behind the increased energy expenditure remain to be fully elucidated but involve an altered intermediary metabolism including increased protein turnover, increased fat oxidation and gluconeogenesis.