Unlocking the potential: Harnessing biomarkers commonly used in clinical practice to predict complications and outcomes in febrile neutropenia

Summary. Febrile neutropenia (FN) is a frequent and serious complication in cancer patients undergoing standard therapy. Its incidence ranges widely, from 10% to 50% in patients with solid tumors and up to 80% in those with hematological malignancies. FN significantly impacts patient outcomes, often necessitating dose reductions or delays in cancer treatment, which can adversely affect overall survival. The mortality rate associated with FN is substantial, between 10% and 30%. Given its profound impact, early identification of patients at high risk for adverse outcomes is crucial. The Multinational Association for Supportive Care in Cancer (MASCC) risk index is a useful tool for stratifying FN risk but has limitations, including subjectivity and difficulty in emergency settings. Biomarkers such as procalcitonin and C-reactive protein (CRP) have demonstrated potential in predicting FN complications. Procalcitonin, in particular, has shown superior performance over the MASCC score in predicting bacteremia and mortality in FN patients. CRP, while useful, is less effective than procalcitonin in certain contexts. Moreover, malnutrition, common in cancer patients, may also influence FN outcomes. Albumin, a marker for nutritional status, correlates with inflammation and malnutrition and may hold promise for FN prediction. Emerging ratios, such as the procalcitonin to albumin ratio (PAR) and the CRP to albumin ratio (CAR), have shown efficacy in predicting complications in various conditions but have not yet been explored in FN. This review emphasizes the urgent need for further research to validate these biomarkers and their ratios in FN, potentially leading to better risk stratification and management strategies, thereby improving patient outcomes.