G-CSF in the treatment of acute myeloid leukemia: is it safe?

Recent studies of granulocyte colony stimulating factor (G-CSF) in the treatment of myeloid leukemia in Japan have revealed that: 1) G-CSF accelerates neutrophil recovery significantly after intensive chemotherapy or bone marrow transplantation (BMT); 2) G-CSF decreases the number of febrile days and the incidence of documented infections; 3) daily administration of G-CSF, starting from two days before chemotherapy or starting from two days after the end of chemotherapy, tended to increase the remission rate; 4) there is no evidence of stimulation by G-CSF of the growth of myeloid leukemia cells if it is used for a short period of time and if the number of leukemic cells is highly reduced by chemotherapy; 5) there is no evidence that G-CSF administration increases relapse rates of leukemia after chemotherapy or BMT. However, until further randomized studies answer these questions, caution must be exercised to avoid unnecessary stimulation of neutrophil production, and G-CSF should not be given to myeloid leukemia patients with a large number of leukemic cells left.