Background: Primary prophylaxis with granulocyte colony-stimulating factors (pp-g-csf) is recommended in patients undergoing chemotherapy carrying a febrile neutropenia (fn) risk of 20% or more. In the present study, we examined clinical practice patterns and the impact of pp-g-csf on fn incidence in women with early-stage breast cancer (ebc) treated with modern adjuvant chemotherapy (act).
Methods: This single-centre retrospective cohort study of women with ebc, who were identified from the pharmacy database and who received at least 1 cycle of modern act from January 2009 to December 2011, was conducted at the Cancer Centre of Southeastern Ontario. Data on patient demographics, pathology, stage distribution, chemotherapy, pp-g-csf use, dose reductions, chemotherapy delays, treatment discontinuation, relative dose intensity, and fn events were collected. Chi-square tests, t-tests, univariate and multivariate logistic regression analyses, and nonparametric Mann-Whitney U-tests were used for data analysis.
Results: Of the 239 women eligible for analysis, 145 (61%) received pp-g-csf, and 50 (21%) developed at least 1 episode of fn. Use of pp-g-csf was associated with a significantly lower rate of fn (14% vs. 31%, p = 0.002) and trends to fewer dose delays (17% vs. 27%, p = 0.060) and dose reductions (19% vs. 25%, p = 0.28). Among women receiving pp-g-csf, higher fn rates were associated with an age of 65 years or older, taxane-based chemotherapy, and prophylaxis with filgrastim.
Conclusions: Clinical practice patterns at our institution showed that more than 50% of ebc patients treated with modern act received pp-g-csf, which led to fewer fn episodes and increased delivery of planned act. The observed high fn risk despite pp-g-csf was linked to older age, taxane-based chemotherapy, and filgrastim.
Keywords: Adjuvant chemotherapy; early-stage breast cancer; febrile neutropenia; filgrastim; pegfilgrastim; practice patterns; primary prophylaxis with granulocyte colony-stimulating factors.