Table I.

Characteristics of studies in the present meta-analysis.

A, Study information
									miRNA expression
Author, year	Country	miRNA	Total no.	Sample tissue	Detection method	Cut-off	Expression status	High expression	Low expression	Refs.
Mavridis et al, 2015	Greece	197	124	Frozen tissue	qPCR	X-tile algorithm	UR	49	75	(10)
Wang et al, 2015	P.R. China	638	189	Serum	qPCR	X-tile algorithm	DR	112	77	(11)
Chen et al, 2013	P.R. China	146α	101	Tissue	qPCR	Median	DR	0	101	(18)
Chen et al, 2017	P.R. China	148α	159	Tissue	qPCR	Median	DR	73	86	(19)
Cui et al, 2013	P.R. China	125b	260	Serum	qPCR	Median	UR	260	0	(20)
Guo et al, 2015	P.R. China	204	126	Plasma	qPCR	Median	DR	66	60	(21)
Li et al, 2015	P.R. China	148α	73	Frozen tissue	qPCR	Mean	DR	31	42	(22)
Liu et al, 2012	P.R. China	21	70	Frozen tissue	qPCR	Mean	UR	48	22	(23)
		141	70					49	21
		200c	70					38	32
Nadal et al, 2014	USA	411	24	Frozen tissue	qPCR	Median	UR	24	0	(24)
		370	33	Frozen tissue	qPCR	Median	UR	33	0
		376α	34	Frozen tissue	qPCR	Median	UR	34	0
Skrzypski et al, 2014	Poland	192	223	Frozen tissue	qPCR	Median	UR	90	133	(25)
		662	223	Frozen tissue	qPCR	Median	UR	90	133
Sun et al, 2013	P.R. China	150	90	Frozen tissue	qPCR	Median	UR	0	90	(26)
		3940-5p	90	Frozen tissue	qPCR	Median		0	90
Võsa et al, 2011	Estonia	374α	36	Tissue	qPCR	Median	DR	18	18	(27)
Wang et al, 2016	P.R. China	148b	39	Frozen tissue	qPCR	Median	DR	18	21	(28)
Jiang et al, 2016	P.R. China	26b	154	Frozen tissue	qPCR	Median	DR	77	77	(29)
Rothschild et al, 2012	Bern	381	18	Tissue	qPCR	Median	DR	3	15	(30)
B, Statistics
	miRNA expression
Author, year	High with T2-4/3-4	Low with T2-4/3-4	High with LNM	Low with LNM	Survival analysis	Multivariate analysis	HR statistic	HR (95% CI)	Follow-up, months	Refs.
Mavridis et al, 2015	30	38			OS	YES	SC	1.91 (1.75–3.19)	84	(10)
Wang et al, 2015	73	51	87	70	OS	YES	SC	0.61 (0.35–1.06)	60	(11)
Chen et al, 2013	0	73	0	66	OS	Unreported	SC	0.56 (0.21–1.51)	60	(18)
Chen et al, 2017	58	70	27	48	OS	YES	SC	0.85 (0.54–1.35)	120	(19)
Cui et al, 2013	260	0			OS	YES	Rep	2.03 (1.14–3.05)	25	(20)
Guo et al, 2015			0	49	OS	YES	SC	0.54 (0.31–0.94)	60	(21)
					DFS			0.78 (0.44–1.36)
Li et al, 2015	0	37	9	30	NA	Unreported			NA	(22)
Liu et al, 2012	34	0	32	0	OS	YES	SC	1.31 (0.42–3.03)	24	(23)
	34	0	32	0				1.02 (0.37–2.82)
	34	0	32	0				1.28 (0.04–2.53)
Nadal et al, 2014	5	0			OS	YES	Rep	3.37 (1.42–8.0)	60	(24)
					DFS			3.32 (1.61–6.88)
	16	0			OS	YES	Rep	3.37 (1.42–8.0)	60
					DFS			3.32 (1.61–6.88)
	22	0			OS	YES	Rep	3.37 (1.42–8.0)	60
					DFS			3.32 (1.61–6.88)
Skrzypski et al, 2014	17	24			OS	YES	SC	1.24 (1.06–1.45)	72	(25)
					DMFS			1.12 (1.01–1.24)
	17	24			OS	YES	SC	2.58 (1.52–4.37)	72
					DMFS			1.23 (1.09–1.38)
Sun et al, 2013	0	52	0	34	NA	YES			NA	(26)
	0	52	0	34
Võsa et al, 2011					OS	YES	SC	0.98 (0.16–5.88)	84	(27)
Wang et al, 2016	8	19	9	7	OS	YES	SC	0.86 (0.31–2.38)	60	(28)
Jiang et al, 2016	27	43	18	51	OS	YES	SC	0.61 (0.26–1.44)	60	(29)
Rothschild et al, 2012					OS	Unreported	SC	0.37 (0.25–0.66)	35	(30)
					EFS			0.48 (0.31–0.93)

‘Total no.’ refers to the number of studies included in the meta-analysis of each microRNA; HR, hazard ratio; 95 % CI; 95% confidence interval; I² is a measure of between-study heterogeneity; LNM, lymph node metastasis; T, tumor stage of cancers; OS, overall survival; RFS, recurrence-free survival; EFS, event-free survival; DFS, disease-free survival; DMFS, distant metastases-free survival; NA, not available; qPCR, quantitative polymerase chain reaction; SC, survival curve; DR, downregulation; UR, upregulation.