Aarts MJ, et al. – Study's objective was to analyze neutrophil recovery in breast cancer patients receiving docetaxel–containing chemotherapy with and without granulocyte colony–stimulating factor prophylaxis. Results of this study did not find any protective effect of prior granulocyte colony–stimulating factor (G–CSF) or prior chemotherapy use on nadir blood cell counts in subsequent cycles.

Methods

• Based on a randomized phase III study in breast cancer patients (n = 167) with >20% risk of febrile neutropenia, experts assessed hematologic toxicity.
• The nadir blood cell counts for patients treated with G-CSF given during all 6 chemotherapy cycles or limited to the first 2 chemotherapy cycles only was the primary endpoint.

Results

• Eligibility criteria were met by 47 patients.
• The median white blood cell count (WBC) and absolute neutrophil count (ANC) nadir slowly decreased from 10.8 × 109/L in cycle 1 to 7.5 × 109/L in cycle 6 and from 7.1 × 109/L to 5.5 × 109/L, in the G-CSF 1-6 arm.
• It was noted that the median WBC nadir in the G-CSF 1-2 arm decreased from 1.2 × 109/L in cycle 3 to 0.9 × 109/L in cycle 6.
• In addition, results highlighted a grade 4 neutropenia of 0.1 × 109/L in cycles 3-6 the in ANC nadir.
• Data demonstrated ANC recovery to normal levels (≥1.5 × 109/L) without delay on day 1 of the next cycle in all patients.