EFFECT OF INSULIN-LIKE GROWTH FACTOR-I ON HOST RESPONSE TO TUMOR

Oncology patients suffer multiple detrimental metabolic alterations. A mong these are catabolism of tumor free body mass to supply nutrients to feed the tumor. This results not only in enhanced tumor growth but also poor wound healing and immunosuppression of the tumor host. Effor ts are therefore being directed at finding methods for improving the n utritional status of the tumor host without enhancing tumor growth. We investigated the ability of two hormones, insulin-like growth factor- 1 (IGF-1) and insulin, to improve physiologic function in tumor-bearin g animals. Tumor-bearing animals received a continuous infusion of IGF -1 (2.20 mg/kg/day), insulin (820 mum/kg/day) or placebo via an osmoti c minipump for 7 days. All animals were pair fed to eliminate nutritio nal intake as a variable. The placebo group lost 31.37 +/- 4.3 g of tu mor free body mass during the study period. The insulin treated group lost 26.34 +/- 7.42 g and the IGF-1 group lost 5.07 +/- 3.25 g (P < 0. 001, ANOVA). IGF-1 treatment failed to alter plasma glucose, lactate, or total amino acid concentration and failed to alter hepatic ketone b ody concentrations, but did improve hepatic mitochondria redox potenti al. Finally, IGF-1 improved splenic weight by 110% and splenic lymphoc yte count by 300%. In conclusion IGF-1 appears to offer potential in s upporting tumor free host body mass without stimulating tumor growth.