The three-tier classification showed stepwise progression of aggressive features (older age, higher grade, larger tumor size) and increasing PBRM1 mutation frequency from the 3p intact to the broad chr3 change group.<h4>Conclusions</h4>This study establishes standardized FISH cut-offs and a practical three-tier classification that captures a continuous spectrum of genomic instability and tumor aggressiveness in CCRCC. Here, PBRM1 is linked to neoplasm.