A prospective, real-world, multinational study of febrile neutropenia (FN) occurrence in oncology patients receiving chemotherapy with intermediate risk of FN: a MASCC Neutropenia, Infection, and Myelosuppression Study Group initiative.

Purpose: Limited knowledge is available on the incidence of febrile neutropenia (FN) in intermediate-risk patients and the rationale for use of granulocyte colony-stimulating factor (G-CSF) in these patients. We aimed to estimate the rate at which patients associated with intermediate risk (10-20%) of FN would develop ≥ 1 episode of FN with a commonly used chemotherapy regimen in clinical practice.

Methods: This prospective, real-world, observational, multinational, multicenter study (December 2016-October 2019) recruited patients with solid tumors or Hodgkin's/non-Hodgkin's lymphoma. Patients receiving chemotherapy with intermediate risk of FN, but not G-CSF as primary prophylaxis were included and observed for the duration of the chemotherapy (≤ 6 cycles and ≤ 30 days after the last chemotherapy administration).

Results: In total, 364 patients (median age, 56 years) with 1601 cycles of chemotherapy were included in the analysis. The incidence of FN was 5% in cycle 1, 3% in cycles 2-3, and 1% in cycles 4-6. The rate of patients with ≥ 1 episode of FN was 9%, and 59% of FN events were reported during cycle 1. The rate of grade 4 neutropenia in cycle 1 was 11%, and 15% of patients experienced ≥ 1 episode of grade 4 neutropenia.

Conclusions: Overall, the incidence of FN was low, with a high incidence in cycle 1 and a decrease in the subsequent cycles. These results provide the real FN risk for common chemotherapy regimens in patients generally excluded from clinical trials. Prophylactic G-CSF in intermediate-risk patients could be considered as per clinician's judgement.