Cancer-induced cachexia: a guide for the oncologist.

Cancer-induced cachexia (CIC) is a paraneoplastic syndrome that may account for up to 20% of deaths in cancer patients. Cachexia includes distinct metabolic changes that are the result of an acute-phase response (APR) mounted by the host as a reaction to tumor cells. These changes include increased muscle proteolysis, increased fat lipolysis, and increased hepatic production of acute-phase proteins such as C-reactive protein and fibrinogen. This APR pathogenesis is an important consideration in trying to treat cachectic patients as most therapies do not target the APR and its subsequent metabolic effects. Although there is currently no cure for CIC, the oncologist frequently encounters cachectic patients in practice, and evidence-based management is needed. We review the current data for assessment of starvation and cachexia, providing guidelines for management that include serum markers and functional assessment. In addition, a review of current therapies is provided, including hypercaloric feeding and nutritional intervention to address starvation, as well as data on appetite stimulants such as corticosteroids and megestrol acetate. Experimental therapies are also discussed, including nonsteroidal antiinflammatory drugs, tumor necrosis factor alpha antagonists, tetrahydrocannabinol, growth hormone, ghrelin, oxandrolone, and omega-3 fatty acids.