WBC Growth Factors: ASCO Guideline Update.

[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 <20% risk of febrile neutropenia, primary prophylaxis with a CSF may be warranted if patients are at a high risk of febrile neutropenia based on age, medical history, or disease characteristics. For stem-cell mobilization, CSFs may be used either alone, after chemotherapy, or in combination with plerixafor or motixafortide. The guideline also provides information about the dosing and selection of CSFs.Additional information is available at www.asco.org/supportive-care-guidelines.