Validation of AJCC 2009 Tumor Staging of 681 N0M0 Clear Cell Renal Cell Carcinoma Treated by Radical Nephrectomy.
Jose M Gonzalez-Berjon, Luan D Truong, Jae Y Ro, Alberto G Ayala, Steven S Shen. The Methodist Hospital and Weill Medical College of Cornell University, Houston, TX
Background: The recent 2009AJCC staging system had a number of changes for pathologic staging of renal cell carcinoma (RCC), including substaging pT2 and combining perirenal/sinus fat invasion with renal vein invasion as pT3a. Clear cell RCC is the most common type of RCC and has a propensity to spread hematogenously through the renal vein. This study attempts to validate the prognostic significance of the 2009 AJCC system in a radical nephrectomy series.
Design: A total of 681 patients with N0M0 clear cell RCC treated by radical nephrectomy with a mean follow up time of 59.9 months were analyzed. The overall survival was calculated using the Kaplan-Meier method and the log rank test was used to compare the survival difference between different staging groups.
Results: Of the 681 patients, the stage distribution was: pT1a – 206 (30.2%), pT1b -153 (22.5%), pT2a – 62 (9.1%), pT2b – 30 (4.4%), pT3a – 220 (32.3%), pT3b/pT3c – 4 (0.6%), and pT4 – 6 (0.9%). A total of 238 patients (34.9%) died during the follow-up period. In univariate analysis, there were significant differences of the overall survival between pT1/T2 vs. pT3, and pT3 vs. pT4 tumors. There was no significant difference between pT1b vs. pT2 (p=0.29) tumors or between pT2a vs. pT2b (p=0.8) tumors. More importantly, there was a significant difference in overall survival between the pT3a with perirenal/sinus fat invasion (n=136) and pT3a with renal vein invasion (with or without fat invasion, n=84), with a 5-year survival of 56% and 36%, respectively (Figure 1) (p=0.001).
Conclusions: Out data prove that recent 2009 TNM staging system is a powerful predictor of survival for clear cell RCC. However, our findings suggest that 1) the value of substaging of pT2 tumors is limited; and 2) renal vein invasion carries a significantly worse prognosis than perirenal/sinus fat invasion, therefore, lumping together perirenal/sinus fat invasion with renal vein invasion as a single substage is unwarranted.
Category: Genitourinary (including renal tumors)
Monday, February 28, 2011 11:00 AM
Platform Session: Section A, Monday Morning