Timely Withdrawal of G-CSF Reduces the Occurrence of Thrombocytopenia During Dose-dense Chemotherapy

Abstract

Post chemotherapy Granulocyte colony stimulating factor (G-CSF) reduces leucopenia, while G-CSF priming shortly before chemotherapy increases myelotoxicity. We performed a trial with a two-schedule crossover design to determine the optimal G-CSF schedule for densified 2-weekly chemotherapy. During 2-weekly chemotherapy days 1 and 2, G-CSF was given on days 3-10, with a G-CSF-free interval before the next chemotherapy cycle of 5 days, or on days 3-13, with a G-CSF-free interval of 2 days. In schedule A, cycle II was preceded by a 5 days, cycle III and IV by a 2 days and cycle V by a 5 days G-CSF free interval. In schedule B, this was 2, 5, 5, and 2 days, respectively. Intra-patient comparison for cycles II versus III and cycles IV versus V showed that platelet (PLT) nadir count was significantly lower for cycles preceded by a 2-days compared to a 5-days G-CSF free interval: mean difference 45.7 x 10(9)/l (95% CI 33.2-58.2, p = 0.0001). Neutrophil count did not differ significantly (p = 0.85). Timely withdrawal of G-CSF in dose-dense chemotherapy reduces chemotherapy-related thrombocytopenia. Leucopenia was not aggravated, reflecting a protective effect of post-chemotherapy G-CSF.