Bacteria inside kidney tumors associate with myeloid inflammation and disease progression: A TRACERx Renal study

Bacteria have increasingly been found to contribute to immune remodeling and disease progression across different solid tumor types. This study investigated whether intratumoral bacteria play a similar role in kidney cancer, where these same immune changes characterize aggressive disease and treatment resistance. Analyzing two large and geographically distinct patient cohorts, the researchers found that live bacteria accumulated in discrete niches within tumors and that higher bacterial abundance predicted worse patient survival. Bacterial hotspots were consistently characterized by the same neutrophil-driven immune profiles that mark aggressive disease, a pattern further confirmed in cell culture experiments showing that live bacteria directly sustained the production of immune-signaling molecules that attract neutrophils. These findings corroborate patterns observed in other solid tumors and establish intratumoral bacteria as a previously overlooked component of the kidney cancer immune landscape, laying the groundwork for exploring them as potential novel therapeutic targets.