Abstract
BACKGROUND: Pulmonary mucormycosis is a life-threatening fungal infection that primarily affects immunocompromised individuals. Underlying malignancy is a recognized risk factor for pulmonary mucormycosis, yet its independent effect on patient outcomes remains uncertain. This study aimed to evaluate the impact of underlying malignancy on the clinical characteristics and 30-day mortality of pulmonary mucormycosis. METHODS: We conducted a retrospective cohort study of 163 adults with proven or probable pulmonary mucormycosis at a single center in Taiwan (2021-2024). Clinical and laboratory variables were compared between groups. Predictors of 30-day all-cause mortality were assessed using Cox proportional hazards regression with purposeful variable selection, and proportional-hazards assumptions were verified using Schoenfeld residuals. RESULTS: The overall 30-day mortality rate was 18.4% (30 of 163 patients). Kaplan-Meier analysis confirmed lower 30-day survival in malignancy patients (log-rank χ(2) = 27.08, df = 1, p < 0.0001). In multivariable analysis, malignancy (aHR 3.65, 95% CI 1.40-9.53), neutrophil-to-lymphocyte ratio per 5 units (aHR 1.10, 95% CI 1.05-1.22), and alkaline phosphatase per 50 U/L (aHR 1.16, 95% CI 1.00-1.64) were independent predictors of early death. Clinically, patients with malignancy predominantly exhibited a cytopenic-immunosuppressed phenotype, whereas those without malignancy more frequently exhibited a metabolic-inflammatory profile characterized by chronic kidney disease or recent COVID-19. CONCLUSION: Underlying malignancy independently triples 30‑day mortality in pulmonary mucormycosis. Easily available laboratory markers-neutrophil‑to‑lymphocyte ratio and alkaline phosphatase-also stratify early risk, underscoring the need for phenotype-tailored and timely antifungal management strategies.