Active surveillance in metastatic pancreatic neuroendocrine tumors: A 20-year single-institutional experience

Table 1 Clinicopathological characteristics of patients with liver metastatic pancreatic neuroendocrine tumors, n (%)

	Number
Age (range, yr)	51 (18-69)
Gender
Male	41 (53.9)
Female	35 (46.1)
T stage
T1	5 (6.5)
T2	24 (31.2)
T3	25 (32.9)
T4	11 (14.4)
N stage
N0	36 (47.4)
N1	40 (52.6)
M stage at diagnosis
M0	31 (40.8)
M1	45 (59.2)
Grade of primary tumor
G1	13 (17.1)
G2	63 (82.9)
Grade of liver metastasis tumor
G1	12 (19.4)
G2	50 (80.6)
Surgery
Resection of primary tumor	51 (67.1)
Non-resection of primary tumor	25 (32.9)
Local treatment of liver metastasis
Yes (resection, TACE, ablation)	33 (43.4)
No local treatment	43 (56.6)
Max diameter of liver metastasis
< 5 mm	27 (35.5)
> 5 mm	49 (64.5)
Mean tumor burden of liver metastasis (range)	0.5% (0.03%-80%)

TACE: Transarterial chemoembolization.