The prognostic value of the site of invasion in T3aN0M0 clear cell renal cell carcinoma.

Background: The 7th Tumor-Node-Metastasis system for clear cell renal cell carcinoma (ccRCC) classified renal sinus fat invasion (SFI), perirenal fat invasion (PFI), or renal vein invasion (RVI) as stage pT3a. However, their close interactions and prognostic value of them remain controversial. The goal of this study is to further analyze their prognostic values for patients with T3aN0M0 ccRCC.

Methods: The data of 1,869 pT3aN0M0 ccRCC patients receiving the radical nephrectomy surgery were collected from the National Cancer Institute Surveillance, Epidemiology, and End Results database of United states from 2010 to 2014. These Patients were grouped as SFI, PFI, SFI + RVI, SFI + PFI, PFI + RVI, and SFI + PFI + RVI according to their corresponding manifestations. Cancer-specific survival (CSS) was determined using the Kaplan-Meier method. Univariate and Multivariate cox proportional-hazards regression methods were used to evaluate the impacts of clinical pathologic parameters on CSS.

Results: Patients with SFI or PFI alone had the similar CSS (P = 0.286) and patients with SFI + PFI + RVI had the worst outcomes. Moreover, significantly more patients with SFI + PFI + RVI had tumor diameter ≥7cm than patients with PFI + RVI, SFI + PFI (68.80% vs. 65.32%, 58.77%, and 55.04%, P = 0.026), respectively. Multivariable analysis showed that RVI + PFI (P = 0.013) and PFI + SFI + RVI (P = 0.011) were the independent factors of CSS.

Conclusions: The results suggest that invasion location can help distinguish patients with T3aN0M0 ccRCC with increased risk of cancer-related mortality.