Correlation Between MASCC Score and the Evolution of Febrile Neutropenia in Patients with Solid Tumors: A Retrospective Study

Background The MASCC (Multinational Association for Supportive Care in Cancer) score is widely used to identify low-risk febrile neutropenia (FN) patients eligible for outpatient management. However, its performance specifically in patients with solid tumors remains insufficiently validated. Methods We conducted a retrospective cohort study at the Centre Hospitalier Universitaire de Sherbrooke (CHUS) between 2011 and 2022. Adult patients admitted for FN secondary to chemotherapy for solid tumors were included. Patients were classified as high-risk (MASCC <21) or low-risk (MASCC ≥21). The primary outcome was the score's ability to predict an uncomplicated clinical course with a specificity of 95%. Secondary outcomes included ICU admission, mortality, duration of hospitalization, intravenous antibiotics, neutropenia and potential days saved with outpatient treatment. Results Among 329 oncologic patients, 227 (69%) were classified as low-risk. The MASCC score showed a sensitivity of 83.5% (95% CI: 77.8–88.2%) and a specificity of 57.3% (95% CI: 47.8–66.4%) for predicting the absence of complications. ICU admission rates were significantly lower among low-risk patients (0.4% vs. 32.7%, p<0.001), as were mortality rates (0.9% vs. 16.8%, p<0.001). Median hospitalization duration was 4 days [IQR (interquartile range) 3–6] for low-risk patients compared to 6 days [IQR 4–10] for high-risk patients (p<0.001). Applying outpatient eligibility criteria could have prevented 486 hospitalization days across 161 patients, with 80.7% experiencing no complications. Conclusion The MASCC score does not accurately identify solid tumor FN patients who would evolve without complications, given its moderate specificity. However, it remains associated with a substantial reduction in hospitalization burden among low-risk patients. Clinical judgment remains essential in outpatient management decisions. Integrating additional clinical parameters may further improve risk stratification in this population.