GROWTH-HORMONE ADMINISTRATION PRESERVES LEAN BODY-MASS IN SARCOMA-BEARING RATS TREATED WITH DOXORUBICIN

Cachexia and malnutrition play a significant role in the morbidity ass ociated with antineoplastic chemotherapy regimens. Conventional nutrit ional support during cancer therapy has shown little benefit in terms of reducing morbidity and mortality. We examined the anabolic properti es of growth hormone (GH) that preserve normal body composition in sar coma-bearing animals treated with doxorubicin. On day 0, 40 male Fisch er 344 rats were inoculated with 10(6) methylcholanthrene-induced sarc oma cells s.c. in the left flank. On day 9, animals were randomized in to 3 groups: control (CTL, n = 13); doxorubicin (DOX, n = 13); and dox orubicin plus GH (DOX-GH, n = 14). Two CTL animals were excluded due t o tumor invasion into the peritoneal cavity. From day 9 to day 23, the DOX-GH group received daily s.c. recombinant rat GH injection (1 mg/k g). On day 13, DOX and DOX-GH groups received 7 mg/kg of DOX i.v. whil e the CTL group received sham i.v. sterile saline injection. Body weig ht and tumor dimensions were measured daily. On day 23, all animals we re weighed and sacrificed. Tumors were resected and weighed. Body comp osition analysis was performed. Plasma GH levels were measured by radi oimmunoassay and insulin growth factor 1 levels were measured by chond rocyte proliferation bioassay. The DOX-GH group had a significantly hi gher mean body weight, carcass weight, total fat free body mass, insul in growth factor 1, and GH plasma levels as compared to the DOX group. No difference in total food intake was observed between the DOX and D OX-GH groups. There was no difference in final tumor weight and tumor growth rate between DOX and DOX-GH groups. Exogenous growth hormone ca n attenuate weight loss and preserve host body composition in tumor-be aring rats treated with doxorubicin without stimulating tumor growth.