Does pathologic upstaging to PT3A portend a worsened prognosis when compared to non-upstaged PT3A renal cell carcinoma: Analysis of the National Cancer Database.

Abstract

624 Background: Pathological T3a (pT3a) renal cell carcinoma (RCC) is often diagnosed at the time of final pathological analysis, though impact of lack pre-treatment detection on surgical outcomes is unclear. We sought to compare outcomes of pathologically upstaged pT3a RCC with pT3a RCC recognized clinically. Methods: We queried the National Cancer Database for incident cases of pT3a pN0/x pM0/x renal cell carcinoma (RCC) treated with radical (RN) or partial nephrectomy (PN) between 2009-2015. Tumors were staged using the AJCC staging system, 7th edition. Pathologically upstaged tumors were defined as those that had a clinical stage of T1 or T2. Non-upstaged tumors had a clinical stage of T3a. Multivariable Cox proportional hazards and Kaplan-Meier survival analysis were performed to study the impact of clinical to pathological upstaging in pT3a tumors on overall survival (OS) in patients treated with RN and PN. Results: A total of 19,538 pT3a tumors were identified of which 7,231 (37%) had concordant clinical stage (non-upstaged) and 12,307 (63%) had lower clinical stage (upstaged). Patients with upstaged tumors had longer time from diagnosis to surgery (31.5 vs. 23.8 days; p<0.001), smaller tumor size (6.7 vs. 7.4 cm; p<0.001), higher rates of treatment with partial nephrectomy (18% vs. 11%; p<0.001), and higher rates of negative margins (92% vs. 89%; p<0.001). On multivariate analysis, age (HR 1.06; p<0.001), Charlson Comorbidity Index (HR 1.51; p=0.006) and positive margin status (HR 1.55; p<0.001) were associated with worse OS. Pathological upstaging was an independent predictor of improved OS following both PN (HR 0.74; 95% CI 0.59-0.91; p=0.006) and RN (HR 0.87; 95% CI 0.82-0.93; p<0.001). Kaplan-Meier analysis showed higher OS for tumors that were upstaged following both PN (5-year OS 73 vs. 70%; p=0.0083) and RN (5-year OS 67 vs. 64%; p<0.001). Conclusions: Most pT3a RCC are pathologically upstaged. Pathological pT3a tumors that were correctly detected clinically were associated with worsened outcomes. While our findings require further confirmation, they call for consideration and refinement of risk stratification protocols in pT3a RCC.