Table 3.

Currently available and potential diagnostic biomarkers for nonalcoholic fatty liver disease-associated hepatocellular carcinoma

Biomarkers	Reported evidence	Ref.
Currently available
AFP	Modest diagnostic ability for HCC in NAFLD patients (AUROC, 0.71–0.88)	[63,84]
DCP	The diagnostic ability for NAFLD-HCC was similar to that of AFP	[63,84]
	Combined use with AFP improved the diagnostic performance
	Used for calculation of GALAD score
AFP-L3	The diagnostic ability for NAFLD-HCC was similar to that of AFP	[63]
	Used for calculation of GALAD score
Under development
Iron status	Elevations of serum iron levels and transferrin saturation were associated with increased risk of HCC in NAFLD patients (HR, 2.91 and 2.02, respectively)	[64]
Proteins	Midkine increased the diagnostic yield in AFP-negative HCC in NAFLD patients; 59.2% of AFP-negative NAFLD-HCC patients had elevation of serum midkine levels	[65-67,72]
	IgM-free AIM had better diagnostic performance for NASH-HCC than AFP or DCP (AUROC, 0.905–0.929)
	Serum TSP-2 levels were significantly associated with advanced fibrosis in NASH patients. Among 164 patients with NAFLD, HCC occurred only in patients with high serum levels of TSP-2
Glycoprotein	Glycosylation patterns of alpha-1 acid glycoprotein may serve as a diagnostic biomarker for AFP-negative HCC in NAFLD patients	[69]
Proteoglycan	Glypican-3 had modest diagnostic ability (AUROC, 0.759), similar to AFP (AUROC, 0.763). When combined with age, sex, DCP and adiponectin, the AUROC increased to 0.948	[65]
Glycopeptide	Site-specific N-glycopeptides from vitronectin may serve as diagnostic biomarkers for NASH-HCC. When used together with AFP, the AUROC were 0.834 and 0.847, compared to 0.791 of AFP alone	[70,71]
	Site-specific N-glycopeptides from serum haptoglobin showed better diagnostic accuracy for NASH-HCC than AFP
Cytokine (adipokine)	Adiponectin had slightly better diagnostic ability (AUROC, 0.770) than AFP (AUROC, 0.763). When combined with age, sex, DCP and glypican-3, the AUROC increased to 0.948	[65]
Cell-free DNA	TERT promoter mutation (C228T) in serum cfDNA showed better diagnostic ability for early NAFLD-HCC than AFP and DCP	[76,78]
	Methylation biomarkers in cfDNA improved the diagnostic performance when combined with AFP
microRNA	The expression levels of exosomal miR-182, miR-301a and miR-373 in both serum and ascetic fluid were higher in NASH-cirrhosis patients with HCC than in those without HCC	[77]

AFP: Alpha-fetoprotein; HCC: Hepatocellular carcinoma; NAFLD: Nonalcoholic fatty liver disease; AUROC: Area under receiver operating characteristic curve; DCP: Des-carboxyprothrombin; AFP-L3: AFP isoform L3; HR: Hazard ratio; IgM: Immunoglobulin M; AIM: Apoptosis inhibitor of macrophages; TSP-2: Thrombospondin-2; NASH: Nonalcoholic steatohepatitis; TERT: Telomerase reverse transcriptase; cfDNA: Cell-free DNA; miR: microRNA.