Review of practice patterns of primary granulocyte-colony stimulating factor prophylaxis and impact on febrile neutropenia rate and chemotherapy delivery in patients with early breast cancer treated with modern adjuvant chemotherapy.

Abstract

e19541 Background: Febrile neutropenia (FN) is a major complication of chemotherapy and is associated with substantial morbidity and mortality. Primary prophylaxis with granulocyte colony-stimulating factors (PP-G-CSF) is recommended for regimens with FN risk above 20%. We undertook a review of practice patterns of PP-G-CSF and impact on febrile neutropenia rate and chemotherapy delivery in patients with early breast cancer (EBC) treated with modern adjuvant chemotherapy (ACT) at the Cancer Centre of Southeastern Ontario. Methods: Women with EBC receiving at least one cycle of modern ACT (taxane containing regimens with or without anthracyclines) between January 2009 and December 2011 were included in our review. We collected demographic, disease-related, treatment-related, and outcome variables for each patient. Results: 239 women were treated with modern ACT during the specified period and were included in our analysis. Median age was 55 (32-80); 197 (82%) were <65 years and 148 (62%) were postmenopausal. 212 (89%) patients were treated with an anthracycline-taxane (A-T) regimen and 27 (11%) with a taxane (T) regimen. 145 patients (61%) received PP-G-CSF: 47 (32%) with filgrastim (F) and 98 (68%) with pegfilgrastim (PF). Of all patients 50 (21%) developed at least one FN episode. PP-G-CSF led to lower FN rate (15% vs 31%; p=0.002), reduced dose delay (17% vs 27%; p=0.060) and dose reduction (19% vs 25%; p=0.28) of planned ACT. In women receiving PP-G-CSF higher rate of FN was associated with age ≥ 65 years (27% vs 12% if < 65 years; OR 2.8, p=0.053); T regimen (30% vs 12% for A-T; OR 3.1, p=0.041) and F use (28% [n=13] vs 8% [n=8] with PF; OR 4.3, p=0.003). Conclusions: In this single-centre retrospective cohort study patients with EBC treated with modern ACT had a high rate of FN (31%) without PP-G-CSF. More than half (61%) of the patients received PP-G-CSF which led to fewer FN episodes and increased delivery of planned ACT; however, the risk of FN remained high at 15%. Factors linked to higher rate of FN despite PP-G-CSF were older age, taxane-based chemotherapy and use of filgrastim.