THE EFFECT OF GM-CSF ON RETICULOCYTES, HEMOGLOBIN AND HEMATOCRIT IN PATIENTS RECEIVING CHEMOTHERAPY FOR SOLID TUMORS

The effect of granulocyte-macrophage colony stimulating factor (GM-CSF ) on reticulocytes, haemoglobin and haematocrit levels of patients rec eiving chemotherapy for solid tumours was assessed. Forty-two patients were randomized into two groups who either did or did not receive GM- CSF 300 U/d on days 8 and 15 post-chemotherapy for neutropenia prophyl axis. Patients were stratified according to tumour type (non small-cel l lung cancer, small-cell lung cancer, ovarian and breast cancer). Eig ht patients with progressive disease were excluded. The 34 patients ev aluated completed six chemotherapeutic cycles of 21 days. They did not receive transfusions or erythropoietin. The estimated dose intensitie s (mg/m(2)/d) for each drug used were significantly higher in the grou p on GM-CSF compared to the group without. Haemoglobin and haematocrit were measured by the H1 (Bayer) haematology analyser and reticulocyt e counts by the now-cytometric reticulocyte analyser, R-1000 (Sysmex). Measurements were conducted on days 1 and 12 of every cycle for six c ycles. At the beginning of therapy there were no significant differenc es between the two groups. However, red cell and reticulocyte counts f ell significantly in the group without GM-CSF compared to the group on GM-CSF. Reticulocyte differences preceded those of haemoglobin and ha ematocrit. The data indicate a positive in vivo effect of GM-CSF on th e erythroid tissue of patients receiving chemotherapy for solid tumour s.