Introduction

To compare recurrence-free survival (RFS) of partial nephrectomy (PN) versus radical nephrectomy (RN) for clinical stage T1 (cT1) renal cell carcinoma (RCC) with pathologic upstaging to T3a among all comers and stratified by pT3a histologic subgroups.

Methods

A retrospective analysis of 1250 patients undergoing PN or RN for cT1 RCC upstaged to pT3a was performed. Baseline characteristics were compared between treatment groups with chi-square and Student t test. RFS was estimated with the Kaplan-Meier method and evaluated as a function of treatment with log-rank test and Cox models adjusting for clinicopathologic variables.

Results

A total of 140 (11.2%) cT1 cases were upstaged to pT3a, 49 (3.9%) after PN and 91 (7.3%) RN. RN cases had greater mean tumor size (5.5cm vs 4.2cm, P<0.001), were more likely to be of moderate/high anatomic complexity (78% vs 45%, P<0.001) and clear cell histology (95 vs 84%, P=0.035), and less likely to demonstrate positive margins (0% vs 15%, P<0.001, Table). Upstaging in RN was more frequent due to sinus fat (53% vs 14%, P<0.001) or venous invasion (45% vs 8%, P<0.001) and less frequent due to perinephric fat invasion (35% vs 80%, P<0.001, Table 1) compared to PN. PN was associated with higher recurrence risk in pT3a RCC (HR=2.04, P=0.019, Figure). Similar results were found in multivariable analysis (HR=3.17, P=0.003). After stratification by pT3a histology, PN was associated with lower RFS in perinephric (P=0.002) and sinus fat invasion (P=0.046, Figure).

Conclusions

PN is associated with higher recurrence risk in cT1 RCC upstaged to pT3a. Patients at high risk for pT3a upstaging may benefit from RN.

Funding

None