Risk stratification by pathological upstaging and tumor necrosis in clinical T1 clear-cell renal cell carcinoma: evidence from a multi-institutional cohort of 1081 patients

Pathological T3 upstaging and tumor necrosis were identified as the only independent predictors of recurrence in cT1 ccRCC. This simplified two-tier risk stratification effectively distinguishes a small high-risk subset (9% of patients) with 25% recurrence rate from the low-risk majority, enabling tailored surveillance strategies and appropriate selection for adjuvant therapy trials.