Extrahepatic biliary cancer: New staging classification

Table 5 Perihilar bile duct tumors (American Joint Commission on Cancer staging 7th edition)

Tumor	TNM classification
T1	Tumor confined to bile duct histologically
T2a	Tumor beyond the wall of bile duct into adjacent fat
T2b	Tumor beyond the wall of bile duct into liver parenchyma
T3	Tumor invades ipsilateral portal vein (R or L) or hepatic artery (R or L)
T4	Tumor invades
	(1) Main portal vein or its branches bilaterally (or)
	(2) Common hepatic artery (or)
	(3) The second-order biliary radicals bilaterally
	(4) Unilateral second-order biliary radicals with contralateral portal vein or hepatic artery involvement
Node
N0	No regional lymph node metastasis
N1	Regional lymph node metastasis (including nodes along the cystic duct, common bile duct, hepatic artery, and portal vein)
N2	Metastasis to periaortic, pericaval, superior mesenteric artery, and/or celiac artery lymph nodes
Metastasis
M0	No distant metastasis
M1	Distant metastasis
Tumor stage	AJCC staging 6th edition
Stage I	T1, N0, M0
Stage II	T2a-b, N0, M0
Stage IIIA	T3, N0, M0
Stage IIIB	T1 or T2 or T3, N1, M0
Stage IVa	T4, N0 or N1, M0
Stage IVb	Any T, N2, M0 or any T, any N, M1

T: Tumor; N: Node; M: Metastases; GB: Gallbladder; PV: Pulmonary vein; AJCC: American Joint Commission on Cancer.