Differing Risk of Cancer Death Among Patients With Pathologic T3a Renal Cell Carcinoma: Identification of Risk Categories According to Fat Infiltration and Renal Vein Thrombosis.

OBJECTIVES: The study objectives were to evaluate the prognostic impact of fat infiltration and renal vein thrombosis in patients with pT3a renal cell carcinoma (RCC) and to identify new prognostic groups. MATERIAL AND METHODS: We analyzed 122 consecutive patients with pT3a who underwent radical nephrectomy for RCC between 2000 and 2011 at the University of Bologna. Cancer-specific survival (CSS) rates were estimated using Kaplan-Meier survival curves; univariable and multivariable analyses were performed with Cox analysis. RESULTS: The mean follow-up was 41.7 ± 35.4 months. Patients with peritumoral/hilar fat infiltration (n = 63) and patients with renal vein thrombosis (n = 18) experienced comparable CSS rates, whereas patients with both fat infiltration plus renal vein thrombosis (n = 41) showed worse survival outcomes than the first group (P = .026). Patients were divided in 2 groups: group A, with fat invasion or renal vein thrombosis, and group B, with concomitant fat invasion and renal vein invasion. Group B showed worse cancer-specific survival than group A (P = .024). At multivariate analysis, this new risk-group stratification was found to be an independent prognostic predictor of CSS (P < .05). CONCLUSIONS: Patients with T3a RCC with both fat invasion and renal vein thrombosis experience worse survival rates when compared with those patients with only 1 prognostic factor. The TNM classification should consider the concomitant presence of those parameters as a different prognostic predictor.