Zinc, copper, and parenteral nutrition in cancer. A review.

Literature concerning zinc and/or copper investigations pertaining to cancer is surveyed; the interrelationships of zinc, copper, and parenteral nutrition (PN) in cancer are examined; and the advantages of adequate nutritional support for patients with malignancies are discussed. Zinc and copper are both essential trace elements and, therefore, are necessary nutrients for cancer patients. Zinc supports growth, including that of neoplasia; copper is a zinc competitor and antagonist; and cancer patients on PN are in danger of becoming both zinc- and copper-deficient. The addition of these trace elements as supplements to PN formulae is undertaken with knowledge of only the approximate concentrations of zinc and copper in total intake, but without knowledge of specific requirements for cancer patients for these trace elements, of all the possible interactions of zinc and copper with each other or different trace elements, or even of zinc and copper lower levels of toxicity in cancer patients; balance studies are needed to determine zinc and copper requirements in them. In the future, it is conceivable that manipulations of the host nutrients might be used to control tumors. This might be accomplished by adjusting total PN formulae so that required nutrients will be presented to a cancer patient in such amounts and in such ratios that a desired alteration may be effected in that patient's metabolism.