Table 3.

Quality score according to the REMARK guidelines.

Study	Year	Samples	Clinical data of the cohort	Immunohisto chemistry	Prognosis	Statistics	Classical prognostic factors	Overall risk of bias
Sakata K et al. [27]	2008	A	I	A	I	I	I	2
Kim SJ et al. [28]	2007	A	A	A	A	A	A	6
Choi SW et al. [29]	2008	A	A	A	I	A	A	5
Roh JL et al. [30]	2009	A	A	A	A	A	A	6
Eckert AW et al. [31]	2010	A	A	A	N/A	I	I	3
Han MW et al. [32]	2011	A	I	A	I	A	A	4
Kondo Y et al. [33]	2011	A	A	A	A	A	A	6
Brockton NT et al. [34]	2012	A	I	A	A	A	A	5
Heo K et al. [35]	2012	I	A	A	I	A	A	4
Pérez-Sayáns M et al. [36]	2012	A	A	A	I	A	A	5
Hwa JS et al. [37]	2015	I	A	A	I	I	I	2
Yang JS et al. [38]	2015	I	A	A	I	A	A	4
Vasconcelos MG et al. [39]	2015	A	I	A	I	I	A	3
Simoes-Sousa S et al. [40]	2016	I	A	A	A	A	A	5
Brockton NT et al. [41]	2017	A	A	A	A	A	A	6
Sáenz-de-Santa-María I et al. [42]	2017	A	I	A	A	A	I	4
Peterle GT et al. [43]	2018	A	A	A	I	A	A	5
Eckert AW et al. [44]	2019	A	A	A	A	A	A	6

Items were assessed as A: Adequate; I: Inadequate; N/A: no description.