UICC 7th, Gallbladder
T1a    lamina propria
T1b    muscular layer
T2    perimuscular connective tissue
T3(a)    serosa, one organ, and/or liver
(T3b)　肝外胆管浸潤
T4　portal vein (b), hepatic artery (b), or two or more extrahepatic organs (a)

Stage Grouping
0    Tis
I    T1
II    T2
IIIA　T3
IIIB　N1
IVA　T4
IVB　M1