Clinical trials of nutritional support in cancer. Parenteral and enteral therapy.

Cancer-related malnutrition is associated with poor prognosis. Although logic would dictate that nutritional support should improve malnutrition and thus outcome, when tested by controlled clinical trials, this has not borne out. With the exception of bone marrow transplantation, routine specialized nutritional support, particularly parenteral nutrition, has not demonstrated consistent therapeutic benefit with respect to any outcome measure and may be associated with harm to patients. The clinician must carefully select appropriate indications for specialized nutritional support in cancer patients.