Table 1.

Cancer glycobiomarkers approved for clinical practice, for which aberrant glycoforms have already been reported (these two criteria—approval by official entities and presenting aberrant glycoforms associated with cancer) were used to select the markers to be included in the table)

Serological glycobiomarker	Cancer type(s)	Altered glycosylation	Type of detection	Clinical applications	References
AFP-L3	Germ-cell hepatoma non-seminomatous Testicular carcinoma	Core fucosylation of AFP-L3	AFP concentration and AFP-L3 glycoform concentration	Diagnosis Prognosis Staging Recurrence detection Therapy monitoring	[23–34]
CA15-3 (MUC1) CA27.29 (MUC1)	Breast carcinoma	Increased level of mannosylated N-glycans, sialylated O-glycans, truncated O-glycans (T, Tn, and respective sialylated derivatives)	MUC1 concentration (both assays use different antibodies that recognize diverse epitopes of the protein)	Therapy monitoring	[23–25, 35–37]
CA19-9	Pancreatic carcinoma Colorectal carcinoma Other gastrointestinal cancers, in combination with other biomarkers	Increased expression of SLea	SLea concentration	Therapy monitoring Recurrence detection Tumour burden assessment	[25, 38–44]
CA125 (MUC16)	Ovarian carcinoma	Increased expression of truncated O-glycans (Tn, STn, T, ST, and core 2), Lex antigen expression, increased expression of bi-antennary complex-type and high mannose-type N-glycans	MUC16 concentration	Prognosis Recurrence detection Therapy monitoring	[23–25, 45–51]
CEA	Colorectal carcinoma Gastric carcinoma Pancreatic carcinoma Breast carcinoma Lung carcinoma	Increased fucosylation and sialylation, increased expression of mannose, Lex, SLex, Ley, and T antigen, increased branched N-glycans	CEA concentration	Staging Prognosis Recurrence detection Therapy monitoring	[23–25, 37, 52–57]
Total PSA Pro2PSA and free PSA	Prostate carcinoma	Altered fucosylation and sialylation, H2 epitope, increase in GalNAc content, LacdiNAc structure, α2,3-sialic acid on the terminal galactose of N-linked oligosaccharides	Total PSA and free PSA concentration	Screening Diagnosis (with digital rectal examination) Pro2PSA and free PSA are used to discriminate cancer from benign disease	[23–25, 58–61]
Tg	Thyroid carcinoma	Increased LCA-reactive Tg, altered sialylation and fucosylation, β1,6-branching of glycans, altered content and structure of poly-LacNAc chains, O-GlcNAcylation	Tg concentration	Therapy monitoring	[23–25, 62–69]

MUC1: mucin 1; CEA: carcinoembryonic antigen; LCA: Lens culinaris agglutinin; Le^x: Lewis x antigen; PSA: prostate-specific antigen; LacdiNAc: GalNAcβ1,4-GlcNAc; Tg: thyroglobulin; LacNAc: N-acetyllactosamine; O-GlcNAcylation: O-linked-N-acetylglucosaminylation