Effect of recombinant human erythropoietin on anemia caused by a murine mammary carcinoma.

: CA NT is a transplantable murine mammary carcinoma that causes progressive anemia accompanied by granulocytosis and splenomegaly. Serum erythropoietin (Epo) levels, as measured by RIA, did not become elevated in anemic tumor-bearing mice; there was no correlation between hematocrit and serum Epo levels. Treatment with recombinant human (rHu) Epo prevented anemia in tumor-bearing mice when given in large doses, commencing on days 3-5 of tumor growth. Recombinant human Epo-treated mice had smaller spleens than controls. When treatment commenced on day 7, the development of anemia was retarded but not completely prevented. Treatment commenced on day 14 was less effective. This study demonstrates that treatment with rHu Epo can markedly influence the course of tumor-induced anemia.