Introduction

Over 50% of patients with advanced cancer suffer from loss of weight and/or appetite during the course of their disease. In a landmark Eastern Cooperative Oncology Group study, Dewys and colleagues found that loss of more than 5% of premorbid weight predicted a poor prognosis, independent of tumor stage, tumor histology, and patient performance status. This weight loss was also associated with a trend towards lower chemotherapy response rates.

How might we explain this prognostic impact? Investigators have hypothesized that loss of lean tissue is directly tied to prognosis. Because lean tissue carries all the body's metabolic machinery, these investigators have suggested there might be a cause and effect relationship between loss of lean tissue and an early demise. In fact, an excessive loss of lean tissue is a hallmark of cancer-associated weight loss. Although weight-losing cancer patients manifest loss of both fat and lean tissue, it is the loss of lean tissue that is the most dramatic and stands in stark contrast to the preferential loss of fat tissue observed in classical starvation. Thus, it may be hypothesized that a reversal of loss of lean tissue might improve prognosis. To date, however, despite ongoing investigation with such agents as eicosapentaenoic acid, thalidomide, adenosine triphosphate, anticytokine therapy, and nonsteroidal anti-inflammatory agents, this hypothesis remains unproved.

Independent of lean tissue wasting, however, a strong argument can be made for diagnosing and palliating anorexia. Wolfe and others interviewed parents of deceased children who died of cancer.