Efficacy of delayed granulocyte colony-stimulating factor after full dose CHOP therapy in non-Hodgkin's lymphoma: A pilot study for a leukocyte count oriented regimen

Bone marrow toxicity is a great challenge for physicians treating patients with non-Hodgkin's lymphoma (NHL) and prescribed chemotherapy. Granulocyte colony-stimulating factor (G-CSF) prevents myelotoxicity, but the optimal timing and scheduling of G-CSF administration has not been ascertained. We investigated leukocyte count oriented G-CSF administration schedules, as related to full dose administration of cyclophosphamide, adriamycin, vincristine, and prednisolone (CHOP) chemotherapy, with shortened intervals. Thirty-eight Japanese patients with NHL were included in this study. The standard CHOP combination was administered in six cycles. Patients were given G-CSF in a dose of 2 mu g/kg/day, subcutaneously starting the day when total leukocytes were < 3,000/mu l. When leukocyte count remained at > 3,000/mu l, G-CSF was started 10 days following CHOP. Treatment with G-CSF was discontinued after the leucocyte count reached > 10,0000/mu l, and CHOP was started the next day (CHOP-G treatment; CHOP-G). Doses were not modified in any patient. Patients over 70 years of age received 2/3 of the standard dosage, In the first cycle of CHOP, the day of initiation of G-CSF was 9.6 days following CHOP in the first cycle and 7.7 to 8.5 days during 2 to 6 cycles. The mean duration of G-CSF injection was 7.4 days with a range from 6.8 to 8.0 days, in each CHOP cycle. The mean intervals of CHOP-G was 14.7 days during six consecutive courses, and there was no prolongation of the intervals, even in later cycles. In 23 patients who received all six cycles of CHOP-G, the overall response rate was 91.3% (73.9% complete remission; CR and 17.4% partial remission; PR). In 32 patients with intermediate grade NHL, the overall response rate was 84.4% (65.5% CR and 18.8% PR). Thus, the full dose CHOP with G-CSF, based on the leukocyte count oriented schedule, can be achieved with shortened intervals, an approach which will increase the quality of life (QOL) for the patients by reducing the days of treatment as well as the cost of G-CSF.