. 2019 Feb 8;14(2):e0209760. doi: 10.1371/journal.pone.0209760

Table 2. Study characteristics included in the systematic review and meta-analysis.

S.No	Study	Population	Study period	Gender	Sample size	Source of sample	Platform	Followup period	miRNA studied	Histological type	Lymph node metastasis/ Distant metastasis	Cancer type/Subtype	Endpoints	HR value	miRNA dysregulation
1	Allaya et al., 2015	North Africa	NR^a	NP^a	43	Tissue	Conventional PCR	NP^a	miR10b	NKC^b, UNCT^c	N0-N3/M0, M1	T1, T2, T3 & T4	OS^h	KMⁿ Curve alone	Upregulated
2	Chen et al., 2016	China	NR^a	M-58/F-23	81	Tissue	qRT-PCR	NP^a	miR17-5p	NP^a	N0-N3/M0,M1	T1, T2, T3 & T4	OS	KMⁿ Curve alone	Upregulated
	He et al., 2017	China	NR^a	M-54/F-23	77	Serum	qRT-PCR	5 year	miR21	NR^a	N0-N3/studied but not mentioned	T1, T2, T3 & T4	OS^h, DFSⁱ	KMⁿ Curve alone	Upregulated
5	Huang et al., 2016	China	NR^a	N/A	62	Tissue	qRT-PCR	NR^a	miR19b-3p	Neoplasm	N0-N3	T1, T2, T3 & T4	OS^h	Provided	Upregulated
6	Liang et al., 2016	China	NR^a	M-40/F-34	74	Serum	qRT-PCR	5 year	miR663	NR^a	Studied but not mentioned exact stage	T1, T2, T3 & T4	OS^h, RFS^l	Provided	Upregulated
7	Liu et al., 2013 a)	China	January 2003 and February 2006,	M-163/F-54	237	Tissue	qRT-PCR	62.5 months	miR29c	Locoregional failure	N0-N3/studied but not mentioned	T1, T2, T3 & T4	OS^h, DFSⁱ, DMFS^m	Provided	20 Samples: miRNA expression alone -Downregulated: 217 samples expressed miRNA with protein—Upregulated
8	Liu et al., 2013b)	China	January 2003 and February 2006.	M-206/F-74	300	Tissue	qRT-PCR	63.9 months	miR451	NR^a	N0-N3	T1, T2, T3 & T4	OS^h, DFSⁱ	Provided	Downregulated
9	Liu et al., 2014	China	January 2001 and December 2006.	M-101/F-27	512	Serum	microarray analysis/qRT-PCR	78.4 months	miR22, miR572, miR638 &miR1234	Keratinizing (SC^e)& nonkeratinizing	N2-N3	T3-T4	OS^h, DMFS^m	Provided	Upregulated
10	Liu et al., 2012	China	312 samples: Jan 16, 2003 and Feb 25,2006/ 153 samples: April 1, 2002, and May 22, 2008	N/A	468	Tissue	microarray analysis/qRT-PCR	62.1 months	41 miRNAs	Keratinizing (SC^e), undifferentiated keratinizing & nonkeratinizing	N0-N3/studied but not mentioned	T1, T2, T3 & T4	DFSⁱ/DMFS^m	Provided	Upregulated
11	Luo et al., 2013	China	NR^a	M-127/F-41	12	Tissue	microarray analysis/qRT-PCR	NR^a	miR18a	NR^a	Studied but not mentioned exact stage	NR^a	OS^h	Provided	Upregulated
12	Ma et al., 2014	China	NR^a	M-136/F-139	275	Tissue	qRT-PCR	NR^a	miR204	NR^a	N0-N3/M0,M1	T1, T2, T3 & T4	OS^h	KMⁿ Curve alone	Downregulated
13	Wang et al., 2014	China	January 2009 and April 2009	M-69/F-31	100	Plasma	qPCR with microRNA assay	86 months	miR483-5p, miR103, miR 29a and let -7c	KSCC^d, NKDC^g, NKUC^f	NR^a	NR^a	OS^h/PFS^k	Provided	miR483-5p and miR103—down regulated; miR29a, let-7c- Upregulated
14	Yu et al., 2013	China	NR^a	M-117/F-56	213	Tissue	qRT-PCR	NR^a	miR18b	NR^a	N0-N3/studied but not mentioned	T1, T2, T3 & T4	OS^h	Provided	Down-regulated
15	Yu et al., 2015	China	NR^a	M-46/F-40	86	Plasma	qRT-PCR	5 year	miR744	NR^a	N0-N3/M0,M1	T1, T2, T3 & T4	OS^h	Provided	Down regulated
16	Zeng et al., 2012	China	NR^a	M-98/F-62	303	Serum	TaqMan Low-Density Array & qRT-PCR	NR^a	miR17, miR20a, miR29c & miR223	SC^e	NR^a	T1, T2, T3 & T4	OS^h, DFSⁱ	KMⁿ Curve alone	Upregulated
17	Zhang et al., 2016	China	January 2006 to December 2009	M-63/F-23	86	Tissue	qRT-PCR	NR^a	miR92a	NR^a	Not lymph node but Distant metastasis studied	T1, T2, T3 & T4	OS^h, DFSⁱ	Provided	Upregulated
18	Zhang et al., 2017	China	July 2006 to October 2015	M-36/F-18	54	Tissue	qRT-PCR	4–62 months	miR324-3p	SC^e	Studied but not mentioned exact stage	T1, T2, T3 & T4	OS^h	KMⁿ Curve alone	Down-regulated
19	Zhao et al., 2016	China	NR^a	M-99/F-43	142	Tissue	qRT-PCR	NR^a	miR3188	NR^a	N0-N3/studied but not reported	T1, T2, T3 & T4	OS^h	KMⁿ Curve alone	Down-regulated
20	Zhao et al., 2017	China	Jan2011 to Dec 2016.	M-67/F-22	89	Tissue	qRT-PCR	5 year	miR92b	NKC^b, KSCC^d	Studied but not mentioned exact stage	T1, T2, T3 & T4	OS^h, DFSⁱ	Provided	Down regulated
21	Zhen et al., 2013	China	NR^a	M-128/F-62	190	Tissue	qRT-PCR	4 to 126 months	miR184	NR^a	NR^a	NR^a	OS^h	Provided	Down regulated
22	Zheng et al., 2013	China	Between 2000 and 2009 and were followed up until 2012	M-1182 / F-483	1665	Tissue	microarray analysis/qRT-PCR	every three months by telephone for the first three years, every six months in years 4 and 5, and annually after that.	miR608	Differentiated and undifferentiated carcinoma	NR^a	NR^a	TTR^j, OS^h	Provided	Not provided

^aNot Reported

^bNon-keratinizing carcinoma.

^cUndifferentiated carcinoma of Nasopharyngeal Type.

^dKSCC-Keratinizing Squamous cell Carcinoma.

^eSC-Squamous cell carcinoma.

^fNKUC- Nonkeratinizing undifferentiated carcinomas.

^gNKDC-Non keratinising differentiated carcinoma.

^hOS-Overall Survival.

ⁱDFS-Disease-free survival.

^jTTR-Time to recurrence.

^kPFS-progression free survival.

^lRFS-Recurrence free survival.

^mDMFS-Distant metastasis-free survival.

ⁿKaplan Meier