Contrast-enhanced ultrasound in association with serum biomarkers for differentiating combined hepatocellular-cholangiocarcinoma from hepatocellular carcinoma and intrahepatic cholangiocarcinoma

Table 1 Baseline characteristics of the study patients with combined hepatocellular-cholangiocarcinoma, intrahepatic cholangiocarcinoma and hepatocellular carcinoma

	CHC, n = 35	Non-CHC		P1	P2
		ICC, n = 29	HCC, n = 70
Tumor size in cm	5.6 ± 3.7	6.9 ± 3.3	5.1 ± 3.1	0.158	0.432
Age in yr	49.3 ± 9.5	55.0 ± 9.3	50.5 ± 9.2	0.018	0.555
Numbers of male	31 (88.6)	24 (82.8)	46 (76.7)	0.720
HBV (+)	30 (85.7)	21 (72.4)	62 (88.6)	0.224	0.756
HCV (+)	3 (8.6)	3 (10.3)	0 (0.0)	1.000	0.035
Liver cirrhosis	23 (65.7)	12 (41.4)	42 (60.0)	0.077	0.671
AFP, > 20 ng/mL	18 (51.4)	3 (10.3)	41 (58.6)	0.001	0.535
CA19-9, > 100 U/mL	4 (11.4)	9 (31.0)	1 (1.4)	0.066	0.041
AC	3 (8.6)	1 (3.4)	1 (1.4)	0.620	0.107

Data are numbers of lesions, with percentages in parentheses or mean ± SD. P1 statistical difference between combined hepatocellular-cholangiocarcinoma (CHC) and intrahepatic cholangiocarcinoma (ICC). P2 statistical difference between CHC and hepatocellular carcinoma (HCC). AC means simultaneous elevated alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 levels (CA19-9).

Table 2 Imaging characteristics of the study patients with combined hepatocellular-cholangiocarcinoma and those with intrahepatic cholangiocarcinoma and hepatocellular carcinoma, n (%)

	CHC, n = 35	Non-CHC		P1	P2
		ICC, n = 29	HCC, n = 70
Echogenic degree				0.692	0.099
Hypo-	32 (91.4)	25 (86.2)	55 (78.6)
Hyper-	3 (8.6)	4 (13.8)	15 (21.4)
Poor boundary	23 (65.7)	22 (75.9)	36 (51.4)	0.422	0.212
Irregular shape	23 (65.7)	20 (69.0)	30 (42.9)	1.000	0.038
APHE pattern				0.757	0.001
Rim-like	6 (17.1)	6 (20.7)	0 (0.0)
Non-rim-like	29 (82.9)	23 (79.3)	70 (100)
Timing of washout onset				0.017	< 0.001
Early, < 60 s	26 (74.3)	28 (96.6)	13 (18.6)
Late, > 60 s	9 (25.7)	1 (3.4)	57 (81.4)
Degree of washout				1.000	0.109
Marked, as observed within first 120 s	2 (5.7)	1 (3.4)	0 (0.0)
Mild	33 (94.3)	28 (96.6)	70 (100.0)
CEUS LI-RADS				0.003	< 0.001
LR-5	9 (25.7)	0 (0.0)	57 (81.4)
LR-M	26 (74.3)	29 (100.0)	13 (18.6)

P1 significant difference between combined hepatocellular-cholangiocarcinoma and intrahepatic cholangiocarcinoma. P2 significant difference between combined hepatocellular-cholangiocarcinoma and hepatocellular carcinoma. APHE: Arterial phase hyperenhancement; CHC: Combined hepatocellular-cholangiocarcinoma; HCC: Hepatocellular carcinoma; ICC: Intrahepatic cholangiocarcinoma; LI-RADS: Liver Image Reporting and Data System.

Table 3 The inter-observer agreement of contrasted-enhanced ultrasound features for the combined hepatocellular-cholangiocarcinomas and non-combined hepatocellular-cholangiocarcinomas lesions

	CHC		K1	Non-CHC		K2
	Reader 1	Reader 2		Reader 1	Reader 2
APHE pattern			0.624			0.524
Rim-like	6	3		8	3
Non-rim-like	29	32		91	96
Timing of washout onset			0.608			0.875
Early, < 60 s	26	22		42	40
Late, > 60 s	9	13		57	59
Degree of washout			0.635			0.662
Marked, as observed within first 120 s	3	3		2	1
Mild	32	32		97	98
CEUS LI-RADS			0.663			0.876
LR-5	9	12		56	58
LR-M	26	23		43	41

Kappa values 0.81-1.0, 0.61-0.80, 0.41-0.60, 0.21-0.40, and 0.00-0.20 correspond to almost perfect, substantial, moderate, fair, and slight, respectively. APHE: Arterial Phase Hyperenhancement; CEUS: Contrasted-enhanced ultrasound; CHC: Combined hepatocellular-cholangiocarcinoma; LI-RADS: Liver Imaging Reporting and Data system.

Table 4 Contrast-enhanced ultrasound Liver Imaging Reporting and Data System categorization and serum biomarkers of 134 patients

Serum biomarker	CHC		HCC		ICC
	LR-5	LR-M	LR-5	LR-M	LR-5	LR-M
AFP (+) CA19-9 (+)	0	31	0	11	0	11
AFP (-) CA19-9 (-)	5	11	26	5	0	18
AFP (+) CA19-9 (-)	4	111	32	61	0	21
AFP (-) CA19-9 (+)	0	1	0	0	0	8
Total	9	26	58	12	0	29

¹Numbers that diagnosis as combined hepatocellular-cholangiocarcinoma (CHC) according to the diagnostic criteria. Alpha-fetoprotein (AFP) (+) = the elevated level of AFP (> 20 ng/mL), AFP (-) = the normal level of AFP (≤ 20 ng/mL), carbohydrate antigen 19-9 (CA19-9) (+) = the elevated level of CA19-9 (> 100 U/mL), CA19-9 (-) = the normal level of CA19-9 (≤ 100 U/mL). HCC: Hepatocellular carcinoma; ICC: Intrahepatic cholangiocarcinoma; LI-RADS: Liver Imaging Reporting and Data System.

Table 5 Diagnostic test results and modified positive predictive value and negative predictive value according to reported combined hepatocellular-cholangiocarcinoma prevalence

CHC prevalence, %	AUC	Sensitivity	Specificity	PPV	NPV	Accuracy
26.1% (35/134)	0.649	40.0	89.9	58.3	80.9	76.9
0.4%[1,13]				1.6	99.7
14.2%[2,3]				9.6	90.1

AUC: Area under the curve; CHC: Combined hepatocellular-cholangiocarcinoma; NPV: Negative predictive value; PPV: Positive predictive value.