Table 2.

MicroRNAs as potential biomarkers for BTC.

	miRNA (source)	Groups	Clinicopathological characteristics associated with deregulated miRNA expression	AUC	Ref.
Downregulated	106a (serum)	CC versus control	Lymph node metastasis; poor prognosis	0.89	[91]
	106a (serum)	CC versus BBD		0.79	[91]
	1537 (bile)	PSC versus PSC/CC		0.78	[92]
	412 (bile)			0.81	[92]
	640∗ (bile)			0.81	[92]
	3189 (bile)			0.80	[92]
Upregulated	21 (plasma)	BTC versus control	Decline of miRNA-21 plasma levels after surgery	0.93	[93]
	21 (plasma)	BTC versus BBD		0.83	[93]
	150 (plasma)	IHC versus control		0.791; 0.920 (+CA19-9)	[26]
	21 (tissue)	CC versus control		0.995	[83]
	21 (tissue)	IHC versus control	Decline of miRNA-21 serum levels after potentially curative surgery	0.908	[84]
	26a (serum)	CC versus control	Decline of miRNA-26a serum levels after potentially curative surgery; shorter progression-free and overall survival	0.899	[94]
	483-5p (serum)			0.77; 0.81 (+miRNA 194)	[95]
	194 (serum)			0.74; 0.81 (+miRNA 483-5p)	[95]
	192 (serum)		Lymph node metastasis; shorter survival	0.803	[96]
	200c (serum)	PSC versus control		0.74	[95]
	1281 (serum)	PSC versus CC		0.83	[92]
	126 (serum)			0.87	[92]
	26a (serum)			0.78	[92]
	30b (serum)			0.78	[92]
	122 (serum)			0.65	[92]
	9 (bile)	BTC versus BBD		0.975	[97]
	145∗ (bile)			0.975	[97]
	944 (bile)			0.765	[97]
	21 (urine)	CC versus control		0.820; 0.849 (+miRNA 192)	[98]
	192 (urine)			0.682; 0.849 (+miRNA 192)	[98]

AUC: area under curve; BBD: benign biliary diseases; BTC: biliary tract cancer; CC: cholangiocarcinoma; IHC: intrahepatic cholangiocarcinoma; miRNA: microRNA; PSC: primary sclerosing cholangitis; PSC/CC: cholangiocarcinoma complicating primary sclerosing cholangitis.