What is the current system of staging for RCC?

T1a: Confined to kidney, <4 cm
T1b: Confined to kidney, >4 cm but <7 cm
T2a: Confined to kidney, >7 cm but <10 cm
T2b: Confined to kidney, >10 cm
T3a: Local extension but not beyond Gerota's fascia or adrenal
extends into renal vein or renal sinus
T3b: Infradiaphragmatic IVC involvement
T3c: IVC involvement above diaphragm
T4: Extension beyond Gerota's fascia

N1: Single ipsilateral regional noderegional nodes
M1: Distant metastases