Molecular biomarkers for the detection of metastatic colorectal cancer cells

Table 1 Sensitivities and specificities of various studies that took blood samples n (%)

Source	Method	Marker	Sensitivity	Specificity	Ref.
Serum	MSP	CDKN2A (p16)	14/52 (27)	44/44 (100)	[32]
Serum	RT-PCR	CEA	51/121 (42)	27/33 (82)	[56]
Serum	RT-PCR	CK20	22/99 (22)	150/150 (100)	[38]
Serum	qPCR	miR-92	80/90 (89)	35/50 (70)	[84]
Serum	CellSearch	EpCAM	20/74 (27)	228/246 (93)	[88]
Serum	CLIA	CEA	188/429 (44)	184/201 (92)	[112]

MSP: Methylation-specific polymerase chain reaction; qPCR: Quantitative reverse transcription polymerase chain reaction (RT-PCR); CLIA: Chemiluminescence immunoassay; CEA: Carcinoembryonic antigen; CK20: Cytokeratin 20; EpCAM: Epithelial cell adhesion molecule.

Table 2 Comparison of biomarkers for detection of metastatic colorectal cancer cells

Marker	Stable	Amplifiable	Widely reported	FDA approval	False negative	False positive	Ref.
DNA methylation	●	●			●		[16]
mRNA		●	●			●	[7]
Micro RNA	●	●					[81]
CellSearch (EpCAM)	●			●	●		[39]
Genetic mutation	●	●			●		[15]

EpCAM: Epithelial cell adhesion molecule; FDA: Food and Drug Administration.