Microwave ablation for peribiliary hepatocellular carcinoma: propensity score analyses of long-term outcomes

Figures & data

Figure 1. Flowchart summarizes the patient enrollment process in this study.

Table 1. Baseline characteristics of the study population.

Characteristic	Peribiliary group (n = 74)	Non-peribiliary group (n = 162)	p Value
Age, years, mean (SD)	56.9+–10.1	55.4+–10.4	.913
Male, n (%)	60 (81.1)	139 (85.8)	.355
Underlying chronic liver disease			.667
Hepatitis B virus	64 (86.5)	138 (85.2)
Hepatitis C virus	7 (9.5)	20 (12.3)
Non-B, non-C hepatitis	3 (4.1)	4 (2.5)
Presence of liver cirrhosis	61 (82.4)	107 (66.0)	.01
Child-Pugh class			.517
Class A	62 (83.8)	130 (80.2)
Class B	12 (16.2)	32 (19.8)
Tumor size (cm)	3.3 (2.8–3.5)	3.1 (2.6–3.5)	.08
Serum AFP level (ng/mL)	31.3 (6.4–98.3)	25.7 (5.0–87.3)	.309
Platelet count (×109/L)	112 (57–145)	119 (64–159)	.581
Antiviral therapy during follow-up	38 (51.3)	60 (37.0)	.038
No. of tumors			.967
1	56 (75.7)	123 (75.9)
2	11 (14.9)	25 (15.4)
3	7 (9.5)	14 (8.6)
Diagnosis method			.008
Clinical and imaging criteria	43 (58.1)	64 (39.5)
Biopsy prior to treatment	31 (41.9)	98 (60.5)
No. of overlapping ablations	1 (1–2)	1 (1–2)	.026
Total ablation time (min)	10 (8–12)	9 (7–13)	.107
Distance between the peribiliary tumor margin and the biliary (mm)	2.1+–0.9	…	…
Distance between the peribiliary tumor margin and bile duct
<5mm	53 (71.6)	…	…
5–10mm	21 (28.4)	…	…

P < .05 was considered to indicate statistical significance.

Table 2. Major complications after MWA.

	Overall Data		Matched data
	Peribiliary Group (n = 74)	Non-peribiliary Group (n = 162)	Peribiliary Group (n = 63)	Non-peribiliary Group (n = 63)
Immediate major complication
Hemoperitoneum	0	1 (0.1)	0	0
Pneumothorax	0	3 (1.9)	0	1 (1.6)
Delayed major complication
Intrahepatic bile duct dilatation	18 (24.3)	4 (2.5)	14 (22.2)	2 (3.2)
Biloma formation	2 (2.7)	0	2 (3.2)	0
Bilio-pleural fistula	0	1 (0.1)	0	1 (1.6)
Abscess	0	1 (0.1)	0	0
Abdominal wall seeding	0	1 (0.1)	0	0
Peritoneal seeding	1 (1.4)	2 (1.2)	1 (1.6)	0
Total	19 (25.7)	13 (8.0)	15 (23.8)	4 (6.3)

Figure 2. Types of recurrence and survival curves in patients from both groups. (A) Progression-free survival rates and (B) overall survival rates.

Figure 3. Types of recurrence and survival curves in matched patients from the two groups. (A) Progression-free survival rates and (B) overall survival rates.

Table 3. Baseline characteristics of study patients after propensity score analysis.

Factor	Peribiliary group	Non-peribiliary group	p Value
	(n = 63)	(n = 63)
Age, years, mean (SD)	56.5+–10.2	55.6+–10.5	.619
Male, n (%)	57 (90.4)	55 (87.3)	.571
Origin of chronic liver disease			0.801
Hepatitis B virus	57 (90.4)	57 (90.4)
Hepatitis C virus	2 (3.2)	1 (1.6)
Non-B, non-C hepatitis	4 (6.3)	5 (7.9)
Presence of liver cirrhosis	45 (71.4)	52 (82.5)	.138
Child-Pugh class B	10 (15.9)	13 (20.6)	.489
Tumor size (cm)	2.2 (1.8–2.5)	2.0 (1.5–2.4)	.156
Serum AFP level (ng/mL)	32.1 (5.4–72.6)	28.0 (5.0–87.3)	.659
Platelet count, 10 9/L	114 (58–121)	119 (55–127)	.812
No. of tumors (1)	50 (79.4)	51 (81)	.958
Antiviral therapy during follow-up	44	40	.45
No. of overlapping ablations	1 (1–2)	1 (1–2)	.451
Total ablation time (min)	10 (6–12)	8 (7–12)	.107

Table 4. Risk factor analysis for recurrence-free survival after MWA.

Characteristic	Univariate analysis		Multivariate analysis
	Relative risk (95% CI)	p Value	Relative risk (95% CI)	p Value
Classification of HCC (Peribiliary)	2.563 (1.880, 3.496)	.001	2.011 (1.424, 2.840)	.001
Age (years)	1.003 (0.989, 1.017)	.683	…	…
Male (sex)	1.100 (0.737, 1.643)	.641	…	…
Origin of chronic liver disease	1.101 (0.877, 1.384)	.407	…	…
Hepatitis B virus
Hepatitis C virus
Other
Liver cirrhosis (absence)	1.727 (1.198, 2.490)	.003	1.318 (0.898, 1.933)	.158
Child-Pugh class B	2.027 (1.440, 2.855)	.001	1.536 (1.065, 2.215)	.022
Tumor size (cm)	1.445 (1.129, 1.851)	.004	1.217 (0.926, 1.599)	.159
α-fetoprotein (ng/mL)	1.083 (0.723, 1.622)	.698	…	…
Serum albumin level (g/L)	0.966 (0.937, 0.995)	.02	0.991 (0.958, 1.025)	.592
Total bilirubin level (mg/dL)	1.011 (1.000, 1.021)	.041	1.004 (0.993, 1.015)	.49
Prothrombin time (INR)	0.995 (0.345, 2.871)	.993	…	…
Platelet count (×10^9/L)	1.000 (0.997, 1.002)	.807	…	…

P < .05 was considered to indicate statistical significance.

Table 5. Risk factor analysis for overall survival after MWA.

Characteristic	Univariate analysis		Multivariate analysis
	Relative risk (95% CI)	p Value	Relative risk (95% CI)	p Value
Classification of HCC (Peribiliary)	2.648 (1.902, 3.885)	.001	2.347 (1.256, 2.570)	.001
Age (years)	0.985 (0.963, 1.006)	.716	…	…
Male (sex)	1.132 (0.861, 1.943)	.543	…	…
Origin of chronic liver disease	1.008 (0.722, 1.684)	.635	…	…
Hepatitis B virus
Hepatitis C virus
Other
Liver cirrhosis (absence)	3.266 (1.800, 5.532)	.001	1.318 (0.898, 1.933)	.158
Child-Pugh class B	2.327 (1.870, 3.652)	.001	2.142 (1.021, 1.987)	.001
Tumor size (cm)	1.538 (1.241, 1.960)	.003	1.382 (0.886, 1.367)	.011
α-fetoprotein (ng/mL)	1.395 (0.765, 2.576)	.287	…	…
Serum albumin level (g/L)	0.903 (0.879, 0.971)	.015	0.894 (0.842, 1.231)	.162
Total bilirubin level (mg/dL)	1.000 (0.983, 1.008)	.112	…	…
Prothrombin time (INR)	0.873 (0.211, 2.131)	.996	…	…
Platelet count (×10^9/L)	0.947 (0.872, 1.001)	.845	…	…

P < .05 was considered to indicate statistical significance.

Figure 4. Subgroup analysis for overall survival rates in HCC patients adjacent to primary branch of intrahepatic biliary compared with those adjacent to secondary branch in the peribiliary group.