Radiofrequency ablation of hepatocellular carcinoma sized > 3 and ≤ 5 cm: Is ablative margin of more than 1 cm justified?

Table 1 Comparison of patient clinical characteristics between the 0.5-1.0 cm group and the > 1.0 cm group n (%)

Variable	0.5-1.0 cm group (n = 158)	> 1.0 cm group (n = 123)	P value1
Age (yr)	52 (24-88)	51 (27-84)	0.467
Gender
Male/female	109 (69.0)/49 (31.0)	86 (69.9)/37 (30.1)	0.873
Pre-existing hepatitis
Hepatitis B	125 (79.1)	106 (86.2)	0.133
Hepatitis C	13 (8.2)	5 (4.1)	0.161
Hepatitis B and C	1 (0.6)	1 (0.8)	0.859
Child-Pugh grade
Class A/class B	78 (49.4)/80 (50.6)	58 (47.2)/65 (52.8)	0.754
Liver cirrhosis
Yes/No	55 (34.8)/103 (65.2)	37 (30.1)/86 (69.9)	0.417
Serum a-fetoprotein level (ng/mL)
< 20	17 (10.8)	11 (8.9)	0.622
20-200	116 (73.4)	93 (75.6)	0.681
> 200	25 (15.8)	19 (15.4)	0.938
Tumor location
S2,S3,S4,S6,S7/S5,S8	73 (46.2)/85 (53.8)	56 (45.5)/67 (54.5)	0.923
Biochemical analysis
AST (IU/L)	46.5 (11.3-235.2)	46.1 (12.1-202.7)	0.793
ALT (IU/L)	48.4 (15.6-240.0)	47.9 (13.8-212.4)	0.560
Alb (g/dL)	3.7 (2.9-4.2)	3.6 (2.8-4.2)	0.460
T-Bil (mg/dL)	0.9 (0.7-1.4)	0.9 (0.6-1.4)	0.594
ALP (IU/L)	83.5 (7.7-376.6)	84.2 (8.1-284.8)	0.744
PT (%)	80.5 (58-100)	83.0 (59-100)	0.262
AFP (ng/mL)	83.2 (6.3-1301.9)	82.5 (5.4-750.7)	0.849
Tumor diameter(cm)	4.1 (3.1-5.0)	4.1 (3.3-5.0)	0.652
No. of ablation sessions before getting AM ≥ 0.5 cm
1 session/2 sessions	115 (72.8)/43 (27.2)	99 (80.5)/24 (19.5)	0.143
Approaches of the first ablation session			0.978
Percutaneous	121 (76.6)	94 (76.4)
Laparoscopic	37 (23.4)	29 (23.6)
Open	0 (0)	0 (0)

Values presented as absolute numbers (percent of cases) or median (range).

¹Fisher’s exact test or Mann-Whitney U test. AFP: α-fetoprotein; Alb: Albumin; ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AM: Ablative margin; AST: Aspartate aminotransferase; PT: Prothrombin time; T-Bil: Total bilirubin.

Table 2 Comparison of the recurrence pattern between the 0.5-1.0 cm group and > 1.0 cm group n (%)

Recurrence pattern	0.5-1.0 cm group (n = 158)	> 1.0 cm group (n = 123)	P value1
LTP only	74 (46.8)	39 (31.7)	0.01
IDR only	34 (21.5)	22 (17.9)	0.45
LTP + IDR	38 (24.1)	16 (13.0)	0.02
Total LTP	112 (70.9)	55 (44.7)	< 0.001
Total IDR	72 (45.6)	38 (30.9)	0.012

¹Fisher’s exact test. IDR: Intrahepatic distant recurrence; LTP: Local tumor progression.

Table 3 Significant variables in the univariate analysis for local tumor progression, intrahepatic distant recurrence, and overall survival (n = 281)

Significant variable	n	P value1
		LTP	IDR	OS
Age (> 65 yr), yes/no	123/158	0.376	0.282	0.103
Gender (male), yes/no	195/76	0.571	0.436	0.854
Liver cirrhosis, yes/no	92/189	0.469	0.645	0.912
Child–Pugh grade (Class B), yes/no	145/136	0.173	0.742	0.811
Tumor location (S5,S8), yes/no	152/129	0.537	0.488	0.635
Tumor size (4.1-5.0 cm), yes/no	154/127	0.007	0.011	0.005
AM (> 1.0 cm), yes/no	123/158	0.001	0.024	0.003
AST (> 40 IU/L), yes/no	166/115	0.658	0.586	0.879
ALT (> 40 IU/L), yes/no	157/124	0.672	0.460	0.734
ALP (> 110 IU/L), yes/no	120/161	0.385	0.473	0.581
Alb (> 3.5 g/dL), yes/no	202/79	0.622	0.564	0.838
T-Bil (> 1 mg/dL), yes/no	93/188	0.541	0.502	0.796
PT (> 70%), yes/no	216/65	0.336	0.573	0.636
AFP (> 200 ng/mL), yes/no	44/237	0.016	0.032	0.028
Post-RF ablation antiviral therapy, yes/no	86/195	0.275	0.547	0.201
Body mass index (> 25 kg/m2), yes/no	83/198	0.611	0.582	0.913
No. of ablation sessions before getting AM ≥ 0.5 cm (2 sessions), yes/no	67/214	0.034	0.041	0.031
Approaches of the first ablation session (Laparoscopic), yes/no	66/215	0.459	0.383	0.728

¹Cox regression analysis. AFP: α-fetoprotein; Alb: Albumin; ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AM: Ablative margin; AST: Aspartate aminotransferase; IDR: Intrahepatic distant recurrence; LTP: Local tumor progression; OS: Overall survival; PT: Prothrombin time; T-Bil: Total bilirubin.

Table 4 Significant variables in the multivariate analysis for local tumor progression, intrahepatic distant recurrence, and overall survival (n = 281)

Significant variable	LTP			IDR			OS
	HR	95%CI	P value1	HR	95%CI	P value1	HR ratio	95%CI	P value1
Tumor size (4.1-5.0 cm), yes/no	1.032	0.521-1.376	0.475	0.891	0.452-1.602	0.744	0.882	0.673-1.572	0.084
AM (> 1.0 cm), yes/no	1.484	0.101-1.812	0.001	1.278	1.137-1.729	0.025	1.604	0.881-2.753	0.002
AFP (> 200 ng/mL), yes/no	0.947	0.540-1.050	0.531	0.509	0.370-1.215	0.546	1.007	0.639-1.158	0.748
No. of ablation sessions before getting AM ≥ 0.5 cm (2 sessions), yes/no	1.012	0.683-1.772	0.663	0.923	0.562-1.218	0.347	0.745	0.321-.431	0.325

¹Cox regression analysis. LTP: Local tumor progression; IDR: Intrahepatic distant recurrence; OS: Overall survival; AFP: α-fetoprotein; AM: Ablative margin.