Percutaneous CT-guided radiofrequency ablation for patients with extrahepatic oligometastases of hepatocellular carcinoma: long-term results

Figures & data

Table 1. Characteristics of the 79 patients.

Characteristics	Data
Patient characteristics
No. of patients	79
Male	73 (92.4)
Female	6 (7.6)
Mean age (y)^a	50.3 ± 13.0
Cause
Hepatitis B	72 (91.1)
Hepatitis C	1 (1.3)
Others	6 (7.6)
ECOG status
0	76 (96.2)
1	3 (3.8)
Child–Pugh class score
5	74 (93.7)
6	4 (5.1)
7	1 (1.3)
Liver cirrhosis
Yes	44 (55.7)
No	35 (44.3)
AFP level
≤400 ng/ml	61 (77.2)
>400 ng/ml	18 (22.8)
Disease-free interval (DFI) (m)
≤12	40 (50.6)
>12	39 (49.4)
BCLC stage before any intervention
0	1 (1.3)
A	35 (44.3)
B	32 (40.5)
C	11 (13.9)
Previous initial therapy
Resection/RFA	67 (84.8)
TACE	12 (15.2)
Use of sorafenib
Yes	14 (17.7)
No	65 (82.3)
Viable tumour in the liver
Yes	12 (15.2)
No	67 (84.8)

Unless otherwise specified, data are numbers or tumours, with percentages in parentheses. AFP: ɑ-fetoprotein; BCLC: Barcelona clinic liver cancer; HBV: hepatitis B virus; HCV: hepatitis C virus.

^a Data are the mean, with the percentage in parentheses.

Table 2. Characteristics of the 116 oligometastatic HCCs.

No. of oligometastases	116
Maximum diameter of oligometastases (mm)^a
Mean	20.3 ± 10.4
Range	5–50
No. of oligometastases ≤30 mm	65 (82.3)
No. of oligometastases >30 mm	14 (17.7)
Number of oligometastases per patients
1	53 (67.1)
2	15 (19.0)
3	11 (13.9)
Number of oligometastases locations per patients
1	67 (84.8)
2	12 (15.2)
Locations of oligometastases
Lung	65 (56.03)
Mean tumour size ± SD (mm)	14.1 ± 8.8
Lymph node	24 (20.69)
Regional	n = 15
Portohepatic	5
Retrocaval	4
Paraaortic	3
Peripancreatic	1
Periceliac	1
Aortocaval	1
Distant	n = 9
Cardiophrenic	8
Mediastinum	1
Pleura and peritoneum	12 (10.34)
Mean tumour size ± SD (mm)	21.3 ± 11.0
Bone	3 (2.59)
Mean tumour size ± SD (mm)	25.7 ± 3.8

^a The size of lymph node metastasis is calculated according to the short diameter.

Figure 1. The length of the oligometastatic state and the unoligometastatic state of the 79 patients. The mean length of the oligometastatic state and the unoligometastatic state was 8.3 ± 6.9 months and 25.3 ± 22.6 months, respectively.

Figure 2. Kaplan–Meier survival curves. (a) Overall survival (OS). (b) Disease-free survival (DFS). (c) Log-rank analysis of OS was stratified according to Child–Pugh score (HR =6.283, p < 0.001). (d) Log-rank analysis of OS was stratified according to the time to unoligometastatic progression (TTUP) (HR =0.136, p < 0.001).

Figure 3. Kaplan–Meier survival curves. (a) Log-rank analysis of DFS was stratified according to the location of oligometastasis in the lung or elsewhere (HR =0.601, p = 0.035). (b) Log-rank analysis of OS was stratified according to the number of oligometastatic organs (HR =1.149, p = 0.734), (c) maximum diameter of oligometastases per patient (HR =1.199, p = 0.175) and (d) the number of oligometastases (HR =1.264, p = 0.388).

Table 3. Prognostic factors associated with overall and disease-free survival.

	Overall survival				Disease-free survival
	Univariate analysis		Multivariate analysis		Univariate analysis		Multivariate analysis
Variable	HR (95% CI)	p value	HR (95% CI)	p value	HR (95% CI)	p value	HR (95% CI)	p value
Age at enrolment^a	0.885 (0.510–1.535)	0.663	…	…	0.960 (0.599–1.538)	0.645	…	…
Liver cirrhosis	1.006 (0.580–1.746)	0.982	…	…	1.108 (0.689–1.780)	0.535	…	…
Child–Pugh score 5^b	6.339 (2.296–17.506)	<0.001	6.283 (2.117–18.646)	0.001	0.543 (0.214–1.377)	0.265	…	…
ECOG performance status	5.687 (1.699–19.044)	0.001	0.446 (0.112–1.783)	0.254	0.512 (0.157–1.670)	0.305	…	…
Use of sorafenib	0.790 (0.382–1.631)	0.521	…	…	0.787 (0.422–1.469)	0.592	…	…
Disease-free survival >12 months	0.966 (0.553–1.685)	0.902	…	…	0.834 (0.518–1.342)	0.394	…	…
Initial BCLC stage				…			…	…
0 and A vs. B and C	1.230 (0.706–2.143)	0.461	…	…	1.355 (0.845–2.172)	0.275	…	…
AFP (ng/ml)	2.327 (1.158–4.678)	0.014	2.004 (0.983–4.083)	0.056	0.633 (0.322–1.243)	0.241	…	…
γ-GGT (U/L)	3.949 (1.874–8.322)	<0.001	0.251 (0.574–3.463)	0.454	0.354 (0.170–0.738)	0.006	0.701 (0.316–1.556)	0.383
Viable tumour in the liver or not	1.250 (0.635–2.463)	0.527	…	…	1.806 (0.949–3.435)	0.073	…	…
Local control of oligometastases	3.409 (1.332–8.726)	<0.001	1.596 (0.444–5.734)	0.474	…	…	…	…
Maximum size of oligometastases	1.199 (0.614–2.343)	0.175	…	…	1.278 (0.708–2.305)	0.238	…	…
Oligometastatic organs	2.187 (1.247–3.836)	0.005	1.741 (0.968–3.129)	0.064	0.601 (0.374–0.966)	0.035	0.354 (0.170–0.738)	0.006
No. of oligometastases	1.264 (0.863–1.850)	0.388	…	…	1.080 (0.777–1.502)	0.961	…	…
No. of oligometastatic organs involved	1.149 (0.513–2.577)	0.734	…	…	0.983 (0.501–1.930)	0.735	…	…
TTUP ≤6 months	0.114 (0.058–0.224)	<0.001	0.136 (0.067–0.277)	<0.001	…	…	…	…

A competing risk regression model for OS, DFS and COX proportional hazards regression model for death were used for both analyses. To convert nanograms per millilitre to micrograms per litre, multiply by 1.0. HR: hazard ratio; CI: confidence interval; ECOG: Eastern Cooperative Oncology Group; BCLC: Barcelona clinic liver cancer; AFP: ɑ-fetoprotein; γ-GGT: γ-glutamyl-transferase; TTUP: time to unoligometastatic progression.

^a Multivariate analysis was performed, including covariates with a p values < 0.05 in univariate analysis.

^b The Bonferroni correction was used for the cause of liver cirrhosis because of multiple comparisons.