Intratumoral microbiota of pancreatic ductal adenocarcinoma impact patient prognosis by influencing tumor microenvironment

Abstract

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly metastatic potential and a heterogeneous tumor microenvironment. It exhibits limited sensitivity to conventional therapies, necessitating a deeper understanding of its pathogenesis. The role of the intratumoral microbiome in regulating cancer development in PDAC has been the subject of debate. Previous investigations into intra-tumor microbiomes have yielded uncertain results due to sample size limitations and insufficient decontamination procedures. Further research is imperative to elucidate the intricate relationship between intra-tumor microbiomes, the immune landscape of PDAC, and overall prognosis. Results Our findings revealed that the intratumor microbiota in PDAC tissue exhibited lower diversity and distinct communities compared to non-tumor tissues. The top microorganisms distinguishing between patients with long or short survival were used to construct the risk signature. We found that Stenotrophomonas is implicated in short survival of PDAC patients, while Neorickettia and Mediterraneibacter are correlated with long survival. This microbiome-based PDAC subtyping, grounded in prognosis-related signatures, exhibited significant correlations with distinct clinical prognoses and immune microenvironments. Microorganisms associated with negative prognoses were linked to pro-tumor immune activation, while those associated with positive prognoses were linked to anti-tumor immune response activation and a more favorable prognosis. Conclusions Our PDAC subtyping approach, based on a microbiome-derived prognostic risk signature, unveiled compelling associations between the PDAC microbiota and disparities in both clinical prognosis and the tumor microenvironment. These findings suggest that microbiota may serve as a promising biomarker for predicting the prognosis of PDAC.

Keywords

• Pancreatic ductal adenocarcinoma
• Tumor microbiota
• Biomarkers
• Tumor immune microenvironment