Overview

• Researchers from IRB Barcelona and the University of Washington used a highly sensitive method on bladder tissue from 45 donors, analyzing 16 genes and revealing thousands of mutations missed by standard sequencing.
• Male donors showed greater selective expansion of certain mutations in cancer-related genes within otherwise healthy bladder tissue.
• Among donors over 55, smokers frequently carried TERT promoter mutations, supporting evidence that tobacco acts both as a mutagen and as a promoter of pre-existing mutated clones.
• The work provides the first direct evidence of sex- and smoking-related clonal selection in normal bladder tissue rather than in tumors.
• The authors frame the findings as an initial step and propose larger studies and development of urine-based assays to refine risk prediction and early detection.