WBC Growth Factors: ASCO Guideline Update

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual . ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines . Clinical Practice Guidelines and other guidance (“Guidance”) provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and Appendix 2 (online only) for more . PURPOSE To update the ASCO guideline on use of hematopoietic colony-stimulating factors (CSFs) in patients with cancer. METHODS A systematic review identified randomized controlled trials (RCTs), meta-analyses, and systematic reviews that addressed use of CSFs for the prevention or treatment of neutropenic events, or for mobilization of stem cells, in adults with cancer. PubMed and the Cochrane Library were searched for articles published from September 1, 2014, to August 22, 2025. ASCO convened an Expert Panel to review the evidence and formulate recommendations. RESULTS The updated systematic review included 33 RCTs and 16 systematic reviews. Additions to the body of evidence include approval of new CSFs and additional biosimilars, and approval of an additional CXCR4 inhibitor that may be used with CSFs for the mobilization of hematopoietic stem cells. RECOMMENDATIONS Prophylactic use of CSFs to reduce the risk of febrile neutropenia is warranted when the risk of febrile neutropenia from chemotherapy is approximately 20% or higher and no other equally effective and safe regimen that does not require CSFs is available. For patients receiving chemotherapy with a