Prognostic value of circulating tumor cells in esophageal cancer

Table 1 Characteristics of the included studies

Ref.	Country	Study design	Number (M/F)	Age, yr (range)	Population	Detection method	Sample time	Rate% (n/N)1	Cut-off criteria	Curative method	Follow-up	Outcome
Li et al[26], 2016	China	Cohort	140 (117/23)	62.8 ± 8.5 (36-78)	ESCC	Fluorescent IHC	Baseline	44 (62/140)	> 2/5 mL	Surgery	3 yr	OS, DFS
Su et al[25], 2016	China	Prospective cohort	57 (55/2)	54 (36-78)	EC	Flow cytometry	Baseline	50 (29/57)	≥ 21/mL	CCRT	3 yr	OS, PFS
Reeh et al[27], 2015	Germany	Prospective cohort	100 (77/23)	66 (32-85)	EC	CellSearch	Baseline	18 (18/100)	≥ 1/7.5 mL	Surgery	37.5 mo (median)	OS, RFS
Matsushita et al[28], 2015	Japan	Prospective cohort	90 (78/12)	65 (46-98)	ESCC	CellSearch	Baseline and after treatment	27 (25/90)	≥ 1/7.5 mL	Chemotherapy or CRT	10.3 mo (median), range 0.3-36.4 mo	OS
Tanaka et al[29], 2015	Japan	Prospective cohort	38 (30/8)	63 (43-87)	EC	CellSearch	Baseline and after treatment	50 (19/38)	≥ 2/7.5 mL	Chemotherapy or CRT	19 mo (median)	OS
Yin et al[30], 2012	China	Cohort	72 (54/18)	63 (46-83)	ESCC	RT-PCR	Baseline and after treatment	69 (50/72)	Expression of any one of CEA, CK19, survivin	Radiotherapy	2 yr	PFS
Tanaka et al[31], 2010	Japan	Prospective cohort	244 (212/32)	64 (NR)	ESCC	RT-PCR	Baseline and after treatment	13 (34/244)	Expression of any one of CEA, SCCA	Surgery	24.3 mo (median)	OS, DFS
Hoffmann et al[32], 2010	Germany	Cohort	62 (53/9)	61 (NR)	EC	RT-PCR	Baseline	77 (48/62)	Expression of survivin	Surgery	3 yr (median)	OS
Gao et al[33], 20092	China	Cohort	108 (85/23)	58.9 (36-82)	ESCC	RT-PCR	Baseline	47 (51/108)	Expression of survivin	Surgery	19.5 mo (median), range, 1-33 mo	OS, RFS

¹Positive CTCs at baseline;

²Only 48 patients were available for follow-up. M/F: Male/Female; ESCC: Esophageal squamous cell carcinoma; EC: Esophageal cancer; IHC: Immunohistochemistry; CCRT: Concurrent chemoradiotherapy; CRT: Chemoradiotherapy; OS: Overall survival; DFS: Disease-free survival; PFS: Progression-free survival; RFS: Relapse-free survival; CEA: Carcinoembryonic antigen; CK19: Cytokeratin 19; SCCA: Squamous cell carcinoma antigen.