Febrile neutropenia in patients treated with chemotherapy/immune checkpoint inhibition: a MASCC consensus statement.

Chemotherapy/immune checkpoint inhibitor (ICI) therapy is increasingly standard of care for a range of cancers. Increasing numbers of emergency cancer presentations mean alternative pathways are required to ensure sustainable services and improve outcomes. Febrile neutropenia (FN) is common in patients treated with chemotherapy/ICI therapy. Risk stratifying patients with FN is essential to personalise acute management and optimise use of healthcare resources. Management of patients with low-risk FN in an outpatient setting is proven to be safe and effective. The MASCC score is well validated for risk stratification in FN, and patients with a score ≥ 21 are likely to be suitable for outpatient management. It has not been validated in patients treated with combined chemotherapy/ICI regimens. This MASCC position paper outlines an approach for acute ambulatory management of low-risk FN in this cohort and produces ten position points. A literature search was performed up to the 31st May 2025 for outpatient management of FN in patients treated with chemotherapy/ICI therapy. Only one paper met the criteria highlighting the need for prospective and real-world data. Patients treated with a MASCC score < 21 are high risk and require standard neutropenic sepsis management. Empirical usage of high-dose steroids in patients presenting with FN on chemo/ICI therapy with grade ≥ 3 diarrhoea and/or transaminitis is not recommended. Patients treated with chemotherapy/ICI therapy with low-risk FN should be treated on the same pathway as those treated with chemotherapy alone with inclusion criteria adapted to recognise their eligibility. ICI-mediated neutropenia should be considered in patients receiving combined chemotherapy/ICI therapy when the timing of presentation is unanticipated or there is a failure of neutrophil recovery with persistent grade 3/4 neutropenia 10 days following administration. Initial treatment of suspected ICI-mediated neutropenia is to commence high-dose steroids and consider short-acting G-CSF.