Table 2.
The main features of the studies included in the systematic review and meta-analysis.
| Study | Population | Study Period | Gender | Sample Size | Source of Sample | Platform | Follow-up Period | miRNA Studied | WHO Histological Type | Lymph Node Metastasis/Distant Metastasis | T Stage | Endpoints | HR Value | miRNA Dysregulation |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| L Ju et al., 2018 [35] | China | 2007 and 2015 | M-83/F-27 | 110 | Tissue | qRT-PCR | 5 Year | miR-9 | NA | N0-N3 | T1, T2, T3 & T4 | OS | KM Curve alone | Upregulated |
| He H et al., 2018 [36] | China | March 2013 and November 2014 | NA | 42 | Tissue | qRT-PCR | NA | miR-494-3p | NA | NA | NA | NA | NA | Upregulated |
| Zhao L et al., 2018 [37] | China-312/Canada-246 | January 2003 and February 2006 | NA | 558 | Tissue | qRT-PCR | 62.1 Months | miR-29b, miR-29a, and miR-26a | NKUC, NKDC, KSCC |
N0-N3 | T1, T2, T3 & T4 | OS, DFS, DMFS | KM Curve alone | Downregulated |
| Lian Y et al., 2018 [38] | China | NA | NA | 45 | Tissue | qRT-PCR/ Microarray analysis | NA | miR-423-5p | NA | NA | NA | OS, RFS | KM Curve alone | Downregulated |
| Liu B et al., 2018 [39] | China | May 2011 to May 2013 | M-37/F-57 | 94 | Serum | qRT-PCR | 36 Months | miR-150 | NKUC, NKDC, KSCC |
Studied but not mentioned exact stage | T1, T2, T3 & T4 | OS | KM Curve alone | Upregulated |
| Wang YH et al., 2018 [31] | China | March 2013 to July 2015 | M-94/F-45 | 139 | Tissue | qRT-PCR | NA | miR-639 | NKUC, NKDC | NA | NA | DFS | KM Curve alone | NA |
| Liu Y et al., 2018 [40] | China | NA | M-32/F-9 | 41 | Tissue | qRT-PCR | NA | miR-141 | NKUC, NKDC | NA | NA | NA | NA | Upregulated |
| Wang T et al., 2019 [32] | China | NA | M-47/F-19 | 66 | Tissue | qRT-PCR | NA | miR-432 | NA | N0-N3 | T1, T2, T3 & T4 | NA | NA | NA |
| Tan GW et al., 2019 [41] | Chinese-68/Malay-44/Others-7 | NA | M-88/F-31 | 119 | Tissue | qRT-PCR | NA | miR-21, miR-26a, miR-29c, miR-93, miR-205, miR-375 and miR-421 |
NA | N0-N3 | T1, T2, T3 & T4 | NA | NA | miR-21, miR-93, miR-205, and miR-421—Upregulated, miR-26a, miR-29c, and miR-375—Downregulated |
| Zhuo X et al., 2019 [42] | China | NA | M-11/F-51 | 62 | Tissue | Microarray analysis | NA | miR-18a, miR-135b, miR-204, and miR-497 |
NA | Studied but not mentioned the exact stage | NA | OS | KM Curve alone | miR-18 and miR-135b—downregulated, miR-204 and miR-497—Upregulated |
| Qiang H et al., 2019 [43] | China | January 2013 to December 2015 | M-32/F-24 | 56 | Tissue | qRT-PCR | NA | miR-31 | KSCC | NA | NA | OS | KM Curve alone | Upregulated |
| Yang Y et al., 2018 [44] | China | June 2014 and August 2015 | M-17/F-13 | 30 | Tissue | qRT-PCR | NA | miR-122 | NA | NA | NA | OS | KM Curve alone | Downregulated |
| Zhang S et al., 2019 [45] | China | NA | M-126/F-30 | 156 | Tissue | Microarray analysis | NA | miR-142-3p, miR-150, miR-29b, and miR-29c | NKUC, NKDC, KSCC | N0-N3 | T1, T2, T3 & T4 | OS, DFS, DMFS, RFS | KM Curve alone | Downregulated |
| Wu L et al., 2019 [46] | China | March 2015 and November 2016 | M-41/F-22 | 63 | Saliva | Microarray analysis/ qRT-PCR | NA | miR-937-5p, miR-650, miR-3612, miR-4478, miR-4259, miR-3714, miR-4730, miR-1203, miR-30b-3p, miR-1321, miR-1202, and miR-575 |
NKDC | N0-N3 | T1, T2, T3 & T4 | NA | NA | Downregulated |
| Cui Z and Zhao Y, 2019 [47] | China | 2002 and 2008 | M-51/F-28 | 79 | Tissue | RT-PCR | NA | miR-342-3p | NA | Studied but not mentioned exact stage | NA | OS | KM Curve alone | Downregulated |
| Huang Y et al., 2018 [48] | China | NA | M-41/F-21 | 62 | Tissue | qRT-PCR | NA | miR-150 | NKUC | NA | NA | OS | KM Curve alone | Upregulated |
| Feng X et al., 2018 [33] | China | August 2012 and July 2014 | M-52/F-40 | 92 | Tissue | qRT-PCR | NA | miR-495 | KSCC | NA | NA | NA | NA | NA |
| Wan FZ et al., 2020 [49] | China | January 2013 to December 2015 | M-58/F-12 | 72 | Tissue | qRT-PCR | NA | miR-34c | NKUC, NKDC | N0-N3 | T1, T2, T3 & T4 | OS | KM Curve alone | Downregulated |
| Zhang Z et al., 2020 [50] | China | NA | M-39/F-9 | 48 | Serum | qRT-PCR | Till May 2019 | miR-29a, miR-26b, miR-29b, miR-143 and miR-125b |
NKUC, NKDC | N0-N3 | T1, T2, T3 & T4 | PFS, OS | KM Curve alone | Downregulated |
| Huang Q et al., 2020 [51] | China | January 2016 to July 2019. | M-45/F-31 | 76 | Tissue | qRT-PCR | NA | miR-192 | NKUC, NKDC | N0-N3 | T1, T2, T3 & T4 | OS | KM Curve alone | Upregulated |
| Zhang H et al., 2020 [52] | China | 2014 to 2016 | M-270/F-181 | 389 | Plasma | qRT-PCR | NA | miR-140-3p, miR-144-3p, miR-17-5p, miR-20a-5p, miR-20b-5p, and miR-205-5p |
PDSC | Studied but not mentioned exact stage | T1, T2, T3 & T4 | OS | KM Curve alone | miR-144-3p, miR-17-5p, miR-20a-5p, and miR-205-5p—Upregulated and miR-140-3p—Downregulated |
| Wang J et al., 2020 [53] | China | June 2013 and December 2016 | M-102/F-48 | 150 | Plasma | Microarray analysis/ qRT-PCR | Till December 2017 | miR-214-3p | NA | NA | NA | RFS | KM Curve alone | Upregulated |
| Yang J et al. 2020 [54] | China | NA | M-78/F-71 | 149 | Tissue | qRT-PCR | NA | miR-200c | NA | NA | NA | OS | KM Curve alone | Downregulated |
| Deng X et al. 2020 [55] | China | NA | M-75/F-35 | 110 | Tissue | qRT-PCR | NA | miR-296-3p | NA | N0-N3 | T1, T2, T3 & T4 | OS | KM Curve alone | Downregulated |
| Lu T et al. 2020 [34] | China | July 2012 to March 2015 | M-68/F-139 | 207 | Tissue | qRT-PCR | NA | miR-BART13-3p and miR-BART7-3p | KSCC, NKUC, NKDC | N0-N3 | T1, T2, T3 & T4 | DMFS | KM Curve alone | NA |
SCC—Squamous Cell Carcinoma (WHO type I); NKDC—Non-Keratinizing Differentiated Carcinoma (WHO type II); NKUC—Non-Keratinizing Undifferentiated Carcinoma (WHO type III); PDSCC—Partially differentiated Squamous Cell Carcinoma; NA: Not Available; M: Male; F: Female.