The recent eighth tumor-node-metastasis (TMN) staging system classifies renal cell carcinoma (RCC) with perirenal fat invasion (PFI), renal sinus fat invasion (SFI), or renal vein invasion (RVI) as stage pT3a. However, limited data are available on whether these sites have similar prognostic value or recurrence rate. We investigated the recurrence rate based on tumor size, pathological invasion sites including urinary collecting system invasion (UCSI), and clinically detected renal vein thrombus (cd-RVT) with pT3aN0M0 RCC. We retrospectively reviewed 91 patients with pT3aN0M0 RCC who underwent surgical treatment. Patients with tumor size > 7 cm, UCSI, three invasive sites (PFI + SFI + RVI), and cd-RVT showed a significant correlation with high recurrence rates (hazard ration (HR) 2.98, p = 0.013; HR 8.86, p < 0.0001; HR 14.28, p = 0.0008; and HR 4.08, p = 0.0074, respectively). In the multivariate analysis, tumor size of > 7 cm, the presence of UCSI, and cd-RVT were the independent predictors of recurrence (HR 3.39, p = 0.043, HR 7.31, p = 0.01, HR 5.06, p = 0.018, respectively). In pT3a RCC, tumor size (7 cm cut-off), UCSI, and cd-RVT may help to provide an early diagnosis of recurrence.
Keywords: T3a; recurrence; renal cell carcinoma; renal vein thrombus; tumor size; urinary collecting system.