Dose intensity of standard adjuvant CMF with granulocyte colony-stimulating factor for premenopausal patients with node-positive breast cancer

The effects of granulocyte colony-stimulating factor (G-CSF) on total dose and dose intensity of standard oral adjuvant CMF (cyclophosphamide, methotrexate, and 5-fluorouracil) chemotherapy were studied in premenopausal patients with node-positive breast cancer. Treatment consisted of standard CMF and locoregional radiotherapy (on indication). G-CSF was administered if the leukocyte count recovery was insufficient. Fifty-one patients required no G-CSF ('no cytopenia'), and 50 patients received G-CSF ('G-CSF'). Twenty-two patients, however, received no G-CSF support despite insufficient leukocyte recovery ('control'). Following G-CSF, leukocyte recovery was adequate in 83% of the chemotherapy cycles. The proportion of the patients who had a dose intensity greater than or equal to 85% was 90% in the 'no cytopenia' group, 74% in the 'G-CSF' group, and 45% in the 'control' group (p < 0.05). Leukocyte recovery was adequate in 87% of the chemotherapy cycles in the patients who received radiotherapy as compared with 92% of those in the patients without radiotherapy (p < 0.05). In conclusion an adequate leukocyte recovery after G-CSF was found in 83% of all chemotherapy cycles. The dose intensity of the G-CSF group was higher as compared with controls. The impact of radiotherapy on hematological recovery was significant, but not dependent on G-CSF.