Low-risk febrile neutropenia: does combined chemotherapy/immune checkpoint inhibitor necessitate a change in approach?

Purpose: Management of patients with low-risk febrile neutropenia in an outpatient setting guided by the MASCC score is proven to be safe and effective. Most patients on ambulatory low-risk febrile neutropenia pathways are undergoing treatment for breast cancer. Recent data has shown benefit of the addition of immune checkpoint inhibitor therapy to cytotoxic chemotherapy in the neoadjuvant setting for patients with early triple-negative breast cancer. We examined whether the addition of ICI therapy altered the clinical severity of febrile neutropenia in this cohort and the ability to manage these patients in an ambulatory setting.

Methods: An observational analysis was performed at a specialist oncology hospital in the North West of England. We compared patients with triple negative breast cancer presenting with febrile neutropenia following treatment with PC-EC/pembrolizumab to those treated with PC-EC in the neoadjuvant setting.

Results: In the study periods, 152 patients received PC-EC and 151 PC-EC/Pembro. Twenty-five patients presented with FN in the PC-EC/Pembro group compared to 16 in those receiving PC-EC (16% vs 11%, p > 0.05). Patients with febrile neutropenia treated with PC-EC/Pembro had more severe clinical presentations as assessed by the MASCC score (18 vs 24; p = 0.01), had worse physiological parameters (NEWS2 at presentation 3 vs 2; p = 0.023) and had a longer length of hospital stay (median 5 days vs 0 days; p = 0.044). There were no deaths at 30 or 90 days in either cohort.

Conclusion: Triple-negative breast cancer patients receiving neoadjuvant pembrolizumab in addition to PC-EC appear to have more severe presentations with febrile neutropenia. This may necessitate greater caution in pathways for ambulatory management for this cohort.