Efficacy of pegfilgrastim to support neoadjuvant dose-dense epirubicin and cyclophosphamide chemotherapy in breast cancer

Abstract

Purpose: The role of long-acting hematopoietic growth factor in supporting dose-dense chemotherapy and minimizing hematologic toxicity has not been established. We investigated the efficacy and safety of once-per-cycle pegfilgrastim in breast cancer patients receiving neoadjuvant dose-dense epirubicin and cyclophosphamide (ddEC).

Methods: Newly diagnosed stage I to III breast cancer patients received four cycles of ddEC (E, 100 mg/m² and C, 600 mg/m² every 2 weeks) and 6 mg of subcutaneous pegfilgrastim on day 2 of each cycle. The primary endpoint was to evaluate the incidence of chemotherapy delay. Secondary endpoints include the incidences of febrile neutropenia (FN) and grade 3/4 neutropenia during the four ddEC cycles.

Results: A total of 240 patients were enrolled and 913 ddEC cycles were administered in the study. Chemotherapy delay occurred in 15 patients (6.3% of patients, 95% CI 3.2-9.4%) for 17 cycles (1.9% of cycles, 95% CI 1.0-2.8%). The most frequent cause of chemotherapy delay was transaminase elevation (10 patients, 12 cycles). A total of 12 patients (5.0%, 95% CI 2.2-7.8%) developed 13 episodes of FN. Of the 221 patients that completed four ddEC cycles with pegfilgrastim support, 209 patients (94.6%, 95% CI 91.6-97.6%) had a 100% relative dose intensity (RDI). A RDI ≥ 85% was achieved in 217 of 221 patients (98.2%, 95% CI 96.5-99.9%). Bone pain of any grade was recorded in 85 of 220 evaluable patients (38.6%, 95% CI 32.2-45.0%).

Conclusions: Pegfilgrastim is effective and safe in facilitating four cycles of neoadjuvant ddEC, with low incidences of chemotherapy delay and febrile neutropenia.

Keywords: Breast cancer; Dose-dense chemotherapy; Febrile neutropenia; Pegfilgrastim.