Introduction

Pathological upstaging (PU) may be noted after surgical management of clinically localized renal cell carcinoma (RCC). We investigated rates and risk factors for PU in the setting of different clinical stages, as well as impact on PU recurrence and survival, and the effect of nephron sparing surgery in setting of PU.

Methods

Multicenter, retrospective analysis of patients with clinically localized RCC (cT1-2). Patients were stratified by presence of T3a PU and by surgical approach. Primary outcome was recurrence. Secondary outcome was overall survival (OS). Multivariable analysis (MVA) was used for recurrence, and Kaplan?Meier analysis (KMA) was utilized for recurrence free survival (RFS) and OS.

Results

We analyzed 2443 patients (1093 RN/1350 PN, mean follow up 69.4 months). Rate of T3a PU was 13.3% (cT1a 6.3%, cT1b 15.3%, cT2 31.6%, p<0.001). Compared to pT1-2 tumors, T3aPU had similar positive margin rates (3.0% vs. 4.3%, p=0.235) but higher rate of recurrence (7.4% vs. 31.0%, p<0.001) and all-cause mortality (16.1% vs. 27.7%, p<0.001). MVA for recurrence demonstrated T3aPU (OR 2.6, p<0.001), tumor size (OR 1.18, p<0.001), high nuclear grade (OR 1.87, p<0.001), and RN (OR 2.23, p<0.001) to be associated factors. Cumulative risk of recurrence for T3aPU plus high nuclear grade was OR 3.92 (p<0.001). KMA for RFS stratifying T3aPU by cT stage and treatment modality revealed 5 year RFS for PN vs. RN in cT1a (91.1% vs. 74.4%, p=0.063), cT1b (100.0% vs. 70.8%, p=0.031) and cT2 (44.7% vs. 43.2%, p=0.557, figure). KMA for OS stratifying T3a PU for different cT stage and treatment modality revealed 5 year OS for PN vs. RN in cT1a (95.0% vs. 83.4%, p=0.074), cT1b (100.0% vs. 74.1%, p=0.088) and cT2 (83.3% vs. 60.6%, p=0.207; figure).

Conclusions

Patients with T3a PU have worsened RFS and OS compared to patients with similar clinical T stage not upstaged. Recurrence and OS are not adversely affected by PN. Increasing tumor size correlates with increased risk of recurrence, and combination of high nuclear grade and PU places patients at greater risk for recurrence.

Funding

Stephen Weissman Kidney Cancer Research Fund