Clinical pathogen profiles and lung microbiome features in lung infection patients and concurrent cancer: insights from metagenomics next-generation sequencing

Pulmonary infections in immunocompromised cancer patients present significant diagnostic and therapeutic challenges. From Dec 2021 to Aug 2023, 85 patients with pulmonary infection were enrolled and categorized into a cancer group (CP, n = 20) and a non-cancer control group (NCP, n = 18). Pathogen detection was performed using both mNGS and culture and lung microbiome analysis was conducted. mNGS demonstrated a significantly higher pathogen detection rate than culture (P < 0.0001). The CP group exhibited older age (P < 0.001), elevated neutrophil counts (NE) and higher procalcitonin (PCT) levels compared to the NCP group. Furthermore, fungal pathogens were significantly more prevalent in the CP group (P = 0.046). Both cancer status and advanced age were independent influencing factors for the detection of pulmonary fungi. Pulmonary microbiome analysis revealed no significant differences in α -diversity or β -diversity between groups. These findings indicate that mNGS offers superior sensitivity over culture. Cancer-related pulmonary infections present a distinct pathogen profile characterized by a higher prevalence of fungal pathogens. This underscores the need for enhanced clinical vigilance, especially among elderly cancer patients.