Table 1. Characteristics of the studies.

First author and reference	Region	Number of miRNA probes	Tumor type	Number of samples	Time
Yanaihara [10]	North America	352	SCC, AD	104 pairs	2006.3
Seike [16]	North America	389	SCC, AD	28 pairs	2009.6
Cho [17]	Asia	470	AD	10 pairs	2009.6
Raponi [18]	North America	328	SCC	61TU, 10 N	2009.7
Gao [19]	Asia	730	SCC, AD	8 pairs	2010.2
Yang [20]	Asia	711	SCC	3 pairs	2010.3
Xing [21]	North America	818	SCC	15 pairs	2010.6
Gao [22]	Asia	730	SCC	4 pairs	2010.6
Yu [23]	North America	377	AD	20 pairs	2010.12
Boeri [24]	North America	235	SCC, AD	24 pairs + 4 TU	2010.12
Ma [25]	Asia	858	SCC, AD	6 pairs	2011.1
Puissegur [26]	Europe	409	NSCLC	20 pairs	2011.3
Võsa [27]	Europe	858	SCC, AD	24 pairs + 14 TU + 3 N	2011.7
Nymark [28]	Europe	723	various	26 pairs	2011.8
Tan [29]	Asia	924	SCC	174 pairs + 13TU + 14N	2011.11
Donnem [9]	Europe	564	SCC, AD	30TU + 10N	2012.1
Jang [3]	North America	858	AD	56 pairs	2012.7
Solomides [30]	North America	817	SCC, AD	42 TU + 14N	2012.11
Ohba*	Asia	600	various	4 AD + 5 SCC + 8 N	2013.1
Markou [31]	Europe	320	SCC, AD	19 pairs	2013.5
Arima [4]	Asia	470	various	80 AD + 29 SCC + 5 N	2014.1
Vucic [15]	Europe	1372	AD	94 pairs	2014.1
Ma [8]	North America	896	SCC, AD	8 pairs	2014.1
Wu [32]	Asia	365	NSCLC	5 pairs	2014.2
Bjaanæs [33]	Europe	1205	AD	154 TU + 20 N	2014.3
Fujita [5]	Asia	1719	SCC, AD	29 pairs	2014.3
LEE [13]	Asia	1372	SCC, AD	9 pairs	2014.9
Robles [34]	North America	654	AD	32 TU + 30 N	2015.4
ZHU [35]	Asia	2006	SCC, AD	44 pairs	2015.5
Wang [14]	Asia	368	SCC	19 pairs	2015.5
Begum [36]	North America	688	SCC, AD	8 pairs	2015.8
Gasparini [7]	Europe	800	SCC, AD	67 TU + 18 N	2015.12

AD, adenocarcinoma; SCC, squamous cell carcinoma; TU, tumor samples; N, non-cancerous samples; pairs, TU and N samples from the same patient; ‘*’, without publication.