Hematopoietic growth factors and the treatment of tumor-associated anemias.

Erythropoietin, alone or in combination with colony-stimulating factors, is a promising agent in the treatment of patients with cancer-related 'anemia of chronic disorders', chemo/radiotherapy-induced anemia, or anemia due to myelodysplastic or myeloproliferative syndromes. In the first two groups, at least half of the patients can be expected to respond to erythropoietin alone, with an average response delay of about 4 weeks and maximal responses at weekly doses of approximately 1000 U/kg. In myelodysplastic syndromes, only 10-20% of patients respond to conventional doses of erythropoietin, but doses exceeding 1000 U/kg weekly in combination with granulocyte colony-stimulating factor yield response rates of about 40%. Although these results show that hematopoietic growth factors can be used successfully to treat cancer-related anemias, economic constraints preclude their use at the present time.