Table 2.

Definitions of American Joint Committee on Cancer and European Neuroendocrine Tumor Society staging for pancreatic neuroendocrine tumors

	AJCC 7th staging classification		AJCC 8th and ENETS staging classification
T1	Limited to the pancreas, ≤ 2 cm in greatest dimension	T1	Tumor limited to the pancreas, ≤ 2 cm
T2	Limited to the pancreas, > 2 cm in greatest dimension	T2	Tumor limited to the pancreas, 2-4 cm
T3	Beyond the pancreas but without involvement of the superior mesenteric artery	T3	Tumor limited to the pancreas, > 4 cm, or invading the duodenum or common bile duct
T4	Involvement of the celiac axis or superior mesenteric artery (unresectable tumor)	T4	Tumor invades adjacent structures
N0	No regional lymph node metastasis	N0	No regional lymph node metastasis
N1	Regional lymph node metastasis	N1	Regional lymph node metastasis
M0	No distant metastasis	M0	No distant metastasis
M1	Distant metastasis	M1	Distant metastasis
		M1a	Metastasis confined to liver
		M1b	Metastasis in at least one extrahepatic site
		M1c	Both hepatic and extrahepatic metastases

AJCC: American Joint Committee on Cancer; ENETS: European Neuroendocrine Tumor Society.