Clinical characteristics and risk factors for mortality in pulmonary mucormycosis among patients with non-hematologic malignancies

BACKGROUND: Pulmonary mucormycosis (PM) is a life-threatening fungal infection typically reported in neutropenic patients with hematologic malignancies (HM), but its features in non-hematologic malignancy (NHM) patients remain unclear. This study aimed to characterize the clinical presentation, treatment, and outcomes of PM in NHM patients. METHODS: This retrospective study (March 1, 2017-July 31, 2024) at Beijing Chaoyang Hospital included 46 NHM-PM patients, predominantly diabetes mellitus (DM) and solid organ transplantation (SOT). The primary outcome was 90-day all-cause mortality. Survival was analyzed using Kaplan-Meier curves and Cox regression, with adjustment for age, sex, and diabetes mellitus. The proportional hazards assumption was verified (GLOBAL p = 0.515). RESULTS: Among 46 PM patients with NHM, DM was present in 71.7%. The 90-day mortality rate was 37.0% (17/46). Non-survivors had higher rates of respiratory failure, intensive care unit (ICU) admission, and septic shock, along with lower hemoglobin and higher D-dimer and procalcitonin (all P < 0.05). Univariable Cox regression identified solid organ transplantation (HR = 6.97), the use of immunosuppressants (HR = 5.58), elevated D-dimers, and elevated procalcitonin as significant mortality predictors (all P < 0.01), whereas longer hospital stay and longer time to treatment initiation were protective (both P < 0.05). Multivariable Cox regression confirmed the use of immunosuppressants as an independent risk factor (adjusted HR = 7.51, 95% CI: 2.72-20.74, P < 0.001). Kaplan-Meier curves showed significantly worse survival for the use of immunosuppressants and SOT recipients (log-rank P < 0.001 for both). CONCLUSIONS: The use of immunosuppressants and SOT are both important factors associated with 90-day mortality in NHM-PM patients. These findings highlight the poor prognosis associated with immunosuppression and support early, aggressive intervention in this high-risk population. Validation in larger cohorts is warranted.