Features of extrahepatic metastasis after radiofrequency ablation for hepatocellular carcinoma

Table 3 Clinical features of patients with extrahepatic metastasis (n = 44), n (%)

Clinical features	Value
Location of metastasis1
Lymph nodes	16 (36.3)
Bone	12 (27.3)
Lung	13 (29.5)
Solitary/multiple	4 (30.7)/9 (69.2)
Unilateral/Bilateral	4 (30.7)/9 (69.2)
Lower lobe/non-lower lobe/all lobes	2 (15.4)/9 (69.2)/2 (15.4)
Peritoneum	12 (27.3)
Diagnostic modality
Abdomen enhanced CT	30 (68.2)
Abdomen enhanced MRI	3 (6.8)
Spine MRI	3 (6.8)
PET-CT	5 (11.4)
Chest X-ray	3 (6.8)
Chest enhanced CT	3 (6.8%)
Tumor marker increment (AFP, PIVKA)
Both	14 (36.8)
Either	17 (44.7)
AFP/PIVKA	15 (39.5)/2 (5.3)
None	7 (18.4)
N/A	6
Patients diagnosed of EHM with either of abdomen enhanced CT or serum AFP elevation (> 15 IU/mL)	38 (86.4)
Time to extrahepatic metastasis (years, median, range)	2.68 (0.38-10.6)
Intra-hepatic HCC status at diagnosis of EHM (mUICC T stage)
T0/T1/T2	19 (43.2)/5 (11.4)/7 (15.9)
T3/T4a	2 (4.5)/11 (25.0)

¹Nine patients had multiple EHM occurrences (3 patients: lymph node and bone, 3 patients: Lymph node and lung, 1 patient: bone and lung, and 1 patient: Bone and peritoneum). CT: Computed tomography; MRI: Magnetic resonance imaging; PET: Positron emission tomography; AFP: Alpha-fetoprotein; PIVKA-II: Protein induced by vitamin K absence or antagonist-II; N/A: Not applicable; EHM: Extrahepatic metastasis; HCC: Hepatocellular carcinoma; mUICC: Modified Union for International Cancer Control.