Abstract

Background: Chemotherapy-induced febrile neutropenia (CIFN) remains a critical complication in cancer treatment, often necessitating granulocyte colony-stimulating factor (G-CSF) support with filgrastim to expedite neutrophil recovery and minimize infection risk. While filgrastim has shown efficacy, recovery rates vary significantly by cancer type, which may impact patient outcomes and healthcare burden. Objective: To evaluate the impact of filgrastim on ANC recovery time in CIFN patients and assess the association between cancer type and clinical outcomes, including hospital stay and infection rates. Methods: This 5-year retrospective cohort study reviewed 473 CIFN patients treated with filgrastim at a tertiary care center. Patients received standardized doses of filgrastim subcutaneously until reaching ANC recovery (≥1500 cells/µL). Key outcomes assessed were ANC recovery time, duration of hospital stay, infection rates, and treatment-related adverse events. Linear regression analysis examined the relationship between ANC recovery time and clinical outcomes. Results: Filgrastim significantly reduced ANC recovery time, with 85% of patients achieving ANC recovery within five days (median: 3.7 days, IQR: 2–5 days). Patients with solid tumors demonstrated a notably faster recovery than those with hematologic malignancies (median: 3.2 vs. 4.5 days; p < 0.01), emphasizing the potential need for tailored filgrastim protocols by cancer type. Importantly, delayed ANC recovery was associated with prolonged hospitalizations (r² = 0.42, p < 0.001) and an elevated infection risk (r² = 0.16, p = 0.045). Filgrastim was well-tolerated, with only mild, transient bone pain reported in 9% of patients. Conclusion: This study highlights the effectiveness of filgrastim in achieving rapid ANC recovery in CIFN patients, with marked differences in recovery rates between cancer types. The strong association between timely ANC recovery and reduced hospital stays underscores the clinical benefits of filgrastim, supporting its strategic use in CIFN management to optimize patient outcomes. Our findings suggest that individualized filgrastim administration protocols may further enhance recovery, particularly for hematologic malignancy patients.