Prognostic evaluation of perinephric fat, renal sinus fat, and renal vein invasion for patients with pathological stage T3a clear-cell renal cell carcinoma.

The presence of multiple patterns of extrarenal extension is associated with a higher risk of disease progression and cancer-related death after radical nephrectomy compared to isolated involvement of the PF, renal SF, or RV, which carry similar prognostic weight. If validated, these findings may help refine risk stratification of non-metastatic T3a RCC by distinguishing patients with multiple vs one pattern of extrarenal extension.