Prognostic and predictive blood biomarkers in gastric cancer and the potential application of circulating tumor cells

Table 1 Prognostic value of circulating tumor cells in gastric cancer

Characteristic and number of patients		Detection method		Statistic value			Ref.
	17	RT-PCR	CA19 mRNA	OS	P = 0.014	CK19 (+) vs (-)	Yeh et al[44], 1998
I-IV	57	RT-PCR	CEA mRNA	Liver metastasis recurrence	P = 0.03	CEA (+) vs (-)	Miyazono et al[45], 2001
I-IV	106	RT-PCR	CEA mRNA	Recurrence/metastasis	P = 0.02	CEA (+) vs (-)	Sumikura et al[46], 2003
I-IV	46	qRT-PCR	CK20 mRNA	2-yr-survival	P < 0.05	CK20 (+) vs (-)	Friederichs et al[47], 2005
I-IV	41	RT-PCR	CK20 mRNA	OS	P = 0.0363	CK20 (+) vs (-)	Illert et al[48], 2005
I-III	46	RT-PCR	CEA mRNA	Recurrence	P ≤ 0.00022	CEA after sugery (+) vs (-)	Seo et al[49], 2005
I-IV	52	RT-PCR	C-Met mRNA	OS	P = 0.0178	C-Met (+) vs (-)	Uen et al[50], 2006
			MUC1 mRNA	OS	P = 0.0352	MUC1 (+) vs (-)
I-IV	42	qRT-PCR	CEA mRNA	Recurrence/metastasis	P = 0.032	CEA (+) vs (-)	Wu et al[51], 2006
I-IV	64	MAH	hTERT/CK19/CEA/MUC1	Recurrence/metastasis	P = 0.009	All marker (+) vs the others	Wu et al[52], 2006
I-IV	57	RT-PCR	CK20 mRNA	5-yr survival	P > 0.05	CK20 (+) vs (-)	Pituch-Noworolska et al[53], 2007
Metastatic	27	CellSearch System	EpCAM CK8/18/19	OS	P = 0.039	CTC ≥ 2 vs < 2	Hiraiwa et al[54], 2008
I-IV	69	RT-PCR	CK19 mRNA	OS	P = 0.0347	CK19 (+) vs (-)	Koga et al[55], 2008
			CK20 mRNA	OS	P = 0.049	CK20 (+) vs (-)
I-IV	810	RT-PCR	MT1-MMP	Recurrence/metastasis	P = 0.0018	MT1-MMP (+) vs (-)	Mimori et al[25], 2008
I-IV	55	RT-PCR, ELISA	Survivin mRNA	RFS	P = 0.026	Survivin (+) vs (-)	Yie et al[56], 2008
I-IV	70	qRT-PCR	Survivin mRNA	OS	P = 0.036	Survivin high vs low	Bertazza et al[57], 2009
Advanced	51 (2 wk after chemotherapy) 48 (4 wk after chemotherapy)	CellSearch system	EpCAM CK8/18/19	PFS ,OS (2 wk after chemotherapy) PFS ,OS (4 wk after chemotherapy)	P < 0.001	CTC ≥ 4 vs < 4	Matsusaka et al[24], 2010
I-IV	123	qRT-PCR	CEA mRNA	Recurrence	P = 0.001	CEA (+) vs (-)	Qiu et al[58], 2010
				DFS	P = 0.001
I-IV	30	qRT-PCR	CK18 mRNA	RFS	P < 0.001	CK18 (+) vs (-)	Saad et al[59], 2010
				OS	P = 0.001
I-IV	95	qRT-PCR	B7-H3 mRNA	OS	P = 0.046	B7-H3 high vs low	Arigami et al[60], 2011
I-IV	98	RT-PCR, ELISA	Survivin mRNA	DFS	P < 0.001	Survivin (+) vs (-)	Cao et al[61], 2011
I-IV	52	qRT-PCR	miR-200c	OS	P = 0.016	miR-200c high vs low	Valladares-Ayerbes et al[62], 2012
				RFS	P = 0.044
I-IV	75	Immunofluorescence	GFP	OS	P =0.0021	CTC ≥ 5 vs < 5	Ito et al[63], 2012
I-IV	251	CellSearch system	EpCAM CK8/18/19	OS	P < 0.001	CTC (+) vs (-)	Uenosono et al[23], 2013
				RFS	P < 0.001
I-IV	22	CellSearch system	EpCAM CK8/18/19	OS	P = 0.23	CTC ≥ 2 vs < 2	Sclafani et al[64], 2014
				PFS	P = 0.91
I-IV	62	qRT-PCR	KRT19/MUC1/EPCAM/CEACAM5/BIRC5 mRNA	OS	P = 0.003	All marker (+) vs the others	Kubisch et al[65], 2015
				PFS	P < 0.001
I-IV	36	Flow cytometry	CD133 ABCG2	OS	P = 0.034	CD133 (+) vs (-)	Xia et al[66], 2015
I-IV	136	CellSearch system	EpCAM CK8/18/19	PFS	P = 0.016	CTC (+) vs (-)	Okabe et al[67], 2015
I-IV	100	Cell Search system	EpCAM CK8/18/19	OS	P = 0.004	CTC ≥ 5 vs < 5	Lee et al[68], 2015
				PFS	P = 0.004
I-IV	24	FACS-ICC	EpCAM	OS	P = 0.014	CTC ≥ 2 vs < 2	Meulendijks et al[69], 2016
				PFS	P = 0.007
I-IV	136	CellSearch system	EpCAM CK8/18/19	OS	P < 0.001	CTC ≥ 3 vs < 3	Li et al[70], 2016
				PFS	P = 0.001
I-IV	65	Immunofluorescence	OBP-401	OS	P = 0.183	OBP-401 (+) vs (-)	Ito et al[71], 2016
				RFS	P = 0.034
I-IV	106	CellSearch system	EpCAM CK8/18/19	OS	P = 0.003	CTC ≥ 2 vs < 2	Peront et al[72], 2017
				RFS	P = 0.0002
I-IV	43	IsoFlux platform	EpCAM	OS	P = 0.0013	CTC ≥ 17 vs < 17	Brungs et al[73], 2018

qRT-PCR: Quantitative real-time polymerase chain reaction; MAH: Membrane-array hybridization; DFS: Disease-free survival; OS: Overall survival; PFS: Progression-free survival; RFS: Relapse-free survival.

Table 2 Detection of cell-free tumor DNA in gastric cancer

Candidate biomarkers	Sample size	Sample type	Method/technology	Diagnostic value/outcome	Ref.
Total cell-free DNA level b-actin	GC = 53, HC = 21	Plasma	qPCR	AUC = 0.75, P < 0.0001	Sai et al[31], 2007
DNA methylation markers RPRM (Reprimo)	GC = 43, HC = 31	GC tissues and plasma	MSP	95.3% GC, 9.7% HC, P < 0.00001; Strong correlation between methyl status in tissues and plasma	Bernal et al[74], 2008
Gene amplification MYC gene copy number (MYC/GAPDH ratio)	GC = 57, HC = 39	Tissues and plasma	qPCR	AUC = 0.816; Strong positive correlation between MYC levels in GC tissues and plasma (r = 0.342; P = 0.009)	Park et al[75], 2009
RUNX3	GC (preoperative) = 65, GC (postoperative) = 43, HC = 50	Tissues and serum	qMSP	AUC = 0.8651, Sn = 95.5%, Sp = 62.5%; Decrease after surgical resection	Sakakura et al[76], 2009
KCNA4 + CYP26B1	GC = 46, GPL = 46, HC = 30	Serum	Discovery: Methylation microarray in tissues; Testing: MSP	AUC = 0.917, Sn = 91.3%, Sp = 92.1%	Zheng et al[77], 2011
SLC19A3	Discovery: GC = 45, HC = 60; Validation: GC = 20, HC = 20	Plasma	MSRED-qPCR	Increased in GC, P < 0.0001	Ng et al[78], 2011
Alu DNA sequences	GC = 54, HC = 59	Plasma	Alu81-qPCR	AUC = 0.784, Sn = 75%, Sp = 63%	Park et al[32], 2012
FAM5C + MYLK	GC = 58, GPL = 46, HC = 30	Serum	Discovery: MeDIP in cell lines; Testing: MSP	AUC = 0.838, Sn = 77.6%, Sp = 90% for GC vs HC; Sn = 30.4% for GPL vs HC; Decrease after surgical resection	Chen et al[79], 2012
XAF1	GC = 202, HC = 88	Tumor tissues and serum	qMSP	AUC = 0.909, P < 0.0001; 83.9% concordance between tissues and serum	Ling et al[33], 2013
Total cfDNA level	Early GC = 16; advanced GC = 14; HC = 34	Plasma	Measurement of cfDNA concentration	AUC = 0.991, Sn = 96.67%, Sp = 94.11% for GC vs HC	Kim et al[80], 2014
HER2 + MYC	GC = 81; gastritis = 63; HC = 32	Plasma and tissues	FISH and qPCR	AUC = 0.850, Sn = 69%, Sp = 92%	Park et al[34], 2014
HER2 gene copy number (HER2/RPPH1 ratio)	Discovery: GC = 52 (pre and post-operative treatment), HC = 40;Validation: GC = 25 plasma	Plasma and tissues	qPCR	AUC = 0.746, Sn = 53.9%, Sp = 96.7%; Positive correlation between GC tissues and plasma (r = 0.424; P = 0.00721); Decrease in post-treatment plasma in HER2 + GC cases; Sn = 66.7%, Sp = 100%	Shoda et al[35], 2015
TP53	GC = 6	Plasma	Parallel sequencing	ctDNATP53 mutation in three out of six patients (50%)	Hamakawa et al[81], 2015
AKT1, AKT3, PIK3CA, PTEN, ARID1A, TP53 and BRAF	GC = 277	Plasma and tissues	MassARRAY system	32 out of 94 patients (34%) with a tissue mutation had a corresponding mutation in plasma	Fang et al[82], 2016
HER2	GC = 70	Plasma and tissues	dual-color ISH assay	ctDNA had a high concordance of HER2 amplification with tumor tissues(91.4%, Kappa index = 0.784, P < 0.001)	Gao et al[83], 2017
HER2	GC = 60; HC = 30	Plasma and tissues	digital droplet PCR	The preoperative plasma HER2 ratio correlated with the tumor HER2 status (P < 0.001); Sn = 73.3%, Sp = 93.3%	Shoda et al[36], 2017

AUC: Area under the curve; GC: Gastric cancer; GPL: Gastric precancerous lesions; HC: Healthy controls; MeDIP: Methylated DNA immunoprecipitation; MSP: Methylation-specific PCR; MSRED-qPCR: Methylation-sensitive restriction enzyme digestion and real-time quantitative PCR; Sn: Sensitivity; Sp: Specificity; FISH: Fluorescence in situ hybridization.

Table 3 Detection of autoantibodies against tumor associated antigens in gastric cancer

Biomarker signature description	Technology	Study design	Sample size (GC/controls)	Diagnostic value	Ref.
2 TAAs-p62 and Koc	ELISA	GC vs HC	135/82	Sn = 19.3%, Sp = 97.6%, P < 0.01	Zhang et al[84], 2001
3TAAs-IQGAP3, KRT23 and REG3A	PARSE assay	GC vs HC (age and sex matched)	48/46	Sn = 22.9%, Sp = 100%, P < 0.001	Xu et al[85], 2012
3 TAAs-p16, p53 and c-myc	ELISA	GC vs HC	74/82	Sn = 21.6%, Sp = 97.6%; P < 0.001	Looi et al[86], 2006
6 TAAs-p53, Hsp70, HCC-22-5, PrxVI, KM-HN-1 and p90	ELISA	GC vs HC, training set	100/79	Sn = 49.0%, Sp = 92.4%, P < 0.01	Hoshion et al[87], 2017
		GC vs HC, validation set	248/74	Sn = 52.0%, Sp = 90.5%, P < 0.01
7 TAAs - p53, C-myc, p16, IMP1, Koc, p62 and Survivin	ELISA	Cardia GC vs HC	88/140	AUC = 0.73, Sn = 64%, Sp = 87%, P < 0.001	Zhou et al[41], 2015
7 TAAs - C-myc, Cyclin B1, IMP1, Koc, P53, p62 and Survivin	ELISA, fixed cut-off	GC vs HC	91/346	Sn = 52.7%, Sp = 89.9%, P < 0.01	Zhang et al[88], 2003
	ELISA, individual cut-off	GC vs HC	91/346	Sn = 98.9%, Sp = 93.1%, P < 0.001	Koziol et al[89], 2003
45 T7 phage-displayed TAA clones (including NY-ESO-1, DDX53, MAGE antigens etc.)	T7 phage displayed TAA microarray	GC vs HC (age and sex matched)	T:100/100	AUC = 0.79, Sn = 59%, Sp = 90%, P < 0.001	Zayakin et al[42], 2013
			V:235/213	AUC = 0.64, Sn = 58.7%, Sp = 55%, P < 0.001
		GC vs gastritis	235/100	AUC = 0.76, Sn = 58.7%, Sp = 81.5%, P < 0.001
		GC vs gastric ulcer	235/54
64 TAAs (including MAGEA4, CTAG1, TP53, ERBB2_C and SDCCAG8 antigens etc.)	Bead-based multiplex serology	GC vs HC	T:155/224	Sn = 0-12%, Sp = 98%; P > 0.05	Werner et al[90], 2016
		GC vs HC	V:146/97	Sn = 32%, Sp = 87%; P < 0.001
102 TAAs (including CTAG1B/CTAG2, DDX53, IGF2BP2, TP53 and MAGEA3 antigens etc.)	A recombinant antigen microarray	GC vs HC	829/929	AUC = 0.60, Sn = 21%, Sp = 91%, P < 0.001	Meistere et al[43], 2017

AUC: Area under the curve; GC: Gastric cancer; HC: Healthy controls; ND: Not determined; Sn: Sensitivity; Sp: Specificity; TAA: Tumor associated antigen; TSA: Tumor specific antigen; T: Training; V: Validation.