Association of Intratumoral Microbiota with Prognosis in Patients with Lacrimal Gland Tumor.

: While intratumoral microbiota have been identified in various cancers, their presence and clinical significance in lacrimal gland tumors remain largely unexplored. This study investigates the existence, composition, and potential clinical significance of intratumoral bacteria in lacrimal gland tumors. : High-throughput 16S rDNA sequencing was performed on tumor DNA extracted from 89 paraffin-embedded tissues from patients with lacrimal gland tumors. Diversity analysis and LEfSe differential analysis were conducted to identify tumor-type-specific bacterial taxa. LASSO regression and the Cox proportional hazards models were used to analyze the relationship between intratumoral microbiota and prognosis. : Significant differences in the β diversity of intratumoral microbiota were observed across adenoid cystic carcinoma (ACC), carcinoma ex pleomorphic adenoma (CXPA), pleomorphic adenoma (PA), and IgG4-related disease (IgG4-RD) patients. After FDR correction, , , , and were notably enriched in the tumors of ACC, CXPA, PA, and IgG4-RD patients, respectively. Importantly, patients with malignant lacrimal gland tumors who experienced relapse, distant metastasis, or death had significantly higher α diversity within their tumors. Furthermore, specific genera, such as and , were particularly associated with poorer prognosis in patients with malignant lacrimal gland tumors. : This study provides a comprehensive analysis of microbial profiles in lacrimal gland tumors, highlighting distinct microbial characteristics across tumor types. Our findings suggest that intratumoral bacterial diversity and specific genera may serve as potential prognostic markers for malignant lacrimal gland tumors.