Liquid biopsy of gastric cancer patients: Circulating tumor cells and cell-free nucleic acids

Table 3 Circulating cell-free DNA in gastric cancer

Characteristic and number of patients		Controls (n)	Plasma/serum	Detection method		Detection rate/statistic value			Ref.
Unresectable	198	78 (peptic ulcer)	Serum	Immuno-PCR	MG7-Ag	82.8%	(GC)		Ren et al[157]
		118 (chronic gastritis)		Semi quantitative		7.7%	(peptic ulcer)
				PCR
		236 (healthy donors)				5.9%	(chronic gastritis)
						0.8%	(healthy donors)
						P < 0.01	Correlation with metastasis	(a)
N/A	51	30 (gastritis)	Serum	qPCR	EBV DNA	100%	(Pt. with EBER (+)		Lo et al[158]
							in primary tumor)
		197 (healthy controls)				92.9%	(Pt. with EBER (+)
							in filtrating lymphocytes)
						0%	(Pt. with EBER (-)
							in primary tumor)
						23.3%	(gastritis)
						3.6%	(Ctrl.)
I-IV	54	30	Serum	MSP	DAP-kinase	48.1%			Lee et al[85]
					E-cadherin	57.4%
					GSTP1	14.8%
					p15	55.6%
					p16	51.9%
						No detection in controls
I-IV	60	16	Serum	MSP	p16	26.1%	With p16 methylation		Kanyama et al[159]
							in primarily tumor
						0%	Without p16 methylation
							in primarily tumor
						0%	(Ctrl.)
I-IV	109	10	Serum	MSP	p16	18.3%			Ichikawa et al[160]
					E-cadherin	23.9%
					p16 + E-cadherin	36.7%
						No detection in controls
I-IV	41	10	Serum	MSP	p16	22.0%			Koike et al[142]
					E-cadherin	22.0%
					RARb	14.6%
				p16 + E-cadherin + RARb		24.4%
						No detection in controls
I-IV	63	10	Serum	MSP	p16	27.0%			Koike et al[161]
					E-cadherin	23.8%
					RARb	17.5%
				p16 + E-cadherin + RARb		50.8%
						No detection in controls
I-IV	60	22	Serum	qMSP	APC	16.7%			Leung et al[162]
					E-cadherin	13.3%
					hMLH1	41.7%
					TIMP3	16.7%
				Four markers combined		55%
						13.6%	(Ctrl.)
					APC + E-cadherin	OS: P = 0.006	Methylation (+) vs (-)	(b)
I-IV	109	10	Serum	MSP	RARb	23.8%			Ikoma et al[163]
				p16 + E-cadherin + RARb		47.7%
I-IV	53	21	Plasma	qPCR	β-actin (102 bp)	P = 0.03	Pt.(n = 53) vs Ctrl. (n = 21)	(c)	Sai et al[83]
					β-actin (253 bp)	P < 0.0001		(c)
						AUC = 0.75
				DNA integrity (253 bp/102 bp)		P = 0.07		(c)
N/A	4	10	Serum	MSP	RUNX3	100%			Tan et al[164]
					p16	50%
					RASSF1A	25%
					CDH1	25%
						No detection in controls
I-IV	52	20	Serum	MSP	p16	9.6%			Tani et al[147]
	(40 pre-ope)				E-cadherin	9.6%
	(12 post-ope)				RARb	3.8%
				p16 + E-cadherin + RARb		23.1%
I-IV	52	50	Serum	MSP	p16	26.9%	(all Pt.)		Abbaszadegan et al[165]
						60.9%	(Pt. with p16 methylation in primary tumor)
						0%	(Ctrl.)
I-IV	20	22	Plasma	Fluorescence-based assay	DNA concentration↑	P < 0.005	Pt.(n = 20) vs Ctrl. (n = 22)	(d)	Kolesnikova et al[166]
				MSP	MGMT	70%	(Pt.)
						36.4%	(Ctrl.)
					p15	50%	(Pt.)
						18.2%	(Ctrl.)
					hMLH1	25%	(Pt.)
						9.1%	(Ctrl.)
I-IV	47	30 (benign gastric disease)	Serum	MSP	RASSF1A	24.0%	(Pt.)		Wang et al[167]
		30 (healthy controls)				3.3%	(benign gastric disease)
						0%	(healthy controls)
I-IV	20	21	Serum	MSP	HSulf-1	55%	(Pt.)		Chen et al[168]
						19.0%	(Ctrl.)
I-IV	57	79	Plasma	qPCR	MYC/GAPDH↑	P < 0.001	Pt. (n = 57) vs Ctrl. (n = 79)		Park et al[91]
						AUC = 0.841
I-IV	65	50	Serum	qMSP	RUNX3	29.2%	(Pt.)		Sakakura et al[169]
						10%	(Ctrl.)
						AUC = 0.8651	Pt. (n = 65) vs Ctrl. (n = 50)
I-IV	65	40 (benign gastric disease)	Serum	MSP	DLEC1	33.8%	(Pt.)		Zhang et al[170]
		20 (healthy controls)				5%	(benign gastric disease)
						0%	(healthy controls)
I-IV	73	20	Serum	qMSP	TFPI2	9.6%	(Pt.)		Hibi et al[171]
						0%	(Ctrl.)
						P = 0.004	Correlation with LN meta.	(a)
						P = 0.0115	Correlation with distant meta.	(a)
I-IV	65	80	Plasma	qMSP	SLC19A3	P < 0.0001	Pt.(n = 45) vs Ctrl. (n = 60)		Ng et al[172]
							(Validation 1)
						AUC = 0.82	Pt. (n = 20) vs Ctrl. (n = 20)
							(Validation 2)
I-IV	46	30 (healthy controls)	Serum	Methylation CpG island microarray	BX141696	56.5%			Zheng et al[86]
		46 (benign gastric disease)		MSP	WT1	50%
					CYP26B1	73.9%
					KCNA4	67.4%
I-IV	58	30 (healthy controls)	Serum	MeDIP	CHRM2	31.0%			Chen et al[87]
		46 (gastric precancerous lesions)		Methylation CpG island microarray	FAM5C	31.0%
				MSP		P < 0.001	Pre- vs post-operation
					MYLK	70.7%
						P < 0.001	Pre- vs post-operation
					FAM5C + MYLK	77.6%	(GC Pt.)
						10%	(healthy controls)
						30.4%	(gastric precancerous lesions)
I-IV	59	54	Plasma	qPCR	ALU↑	P < 0.001	Pt. (n = 59) vs Ctrl. (n = 54)	(c)	Park et al[84]
						AUC = 0.784
N/A	25	9	Plasma	MSP	ATP4B	64%	(Pt.)		Raja et al[173]
						0%	(Ctrl.)
I-IV	71	21	Serum	qMSP	Vimentin	P = 0.018	Pt. (n = 73) vs Ctrl. (n = 21)	(c)	Shirahata et al[174]
Operable	73	20	Serum	MSP	SOX17	58.9%	(Pt.)		Balgkouranidou et al[175]
						0%	(Ctrl.)
						OS: P = 0.049	Methylation (+) vs (-)	(b)
I-IV	73		Plasma	qPCR	HER2	64.4%	Pt. with 2+/3+ score in HER2 IHC assay		Lee et al[92]
Pt. with 2+/3+ score in HER2 IHC assay
I-IV	202	88	Serum	qMSP	XAF1	69.8%	(Pt.)		Ling et al[88]
						0%	(Ctrl.)
						AUC = 0.909	Pt. (n = 202) vs Ctrl.(n = 88)
						DFS: P < 0.0001	Methylation (+) vs (-)	(b)

a: χ² test/Fisher’s exact test; b: Kaplan-Meier survival curves, Log-rank test/Breslow-Wilcoxon test; c: Unpaired t-test/Mann-Whitney U-test; d: Unknown statistic method. AUC: Area under the receiver operating characteristic curve; LN: Lymph node; MeDIP: Methylated DNA immunoprecipitation; MSP: Methylation specific-PCR; qMSP: Quantitative methylation specific-PCR. qRT-PCR: Quantitative real-time polymerase chain reaction; N/A: Not available; GC: Gastric cancer; EBV: Epstein-barr virus; DAP: Death-associated protein; APC: Adenomatous polyposis coli; OS: Overall survival; HER: Human epidermal growth factor.