Author Year Country Inclusion period Study Design Clinical Stage Histotype N total N upstaged (overall)
Young et al. 1983 USA 1976 – Not mentioned Prospective I-II Not mentioned 100 a 31
Onda et al. 1996 JPN 1987 - 1995 Prospective I-II SMEC 59a 13
Cass et al. 2000 USA 1986 - 1998 Retrospective I SMEC 96 a 37
Le et al. 2001 CAN 1975- 1999 Retrospective I SMEC 94 a 34
Faught et al. 2003 CAN 1985 - 2000 Retrospective I SMEC 128 43
Negishi et al. 2004 JPN 1987 - 2002 Prospective I-III SMEC 150 19
Ayhan et al. 2005 TUR 1981 - 2001 Retrospective I-II SME 102 a 7
Ayhan et al. 2007 TUR 1984 - 2001 Retrospective I SME 169 53
Powless et al. 2009 USA 1994 - 2003 Retrospective I-II SMEC 211 9
Mujezinović et al. 2010 SVN 1994 - 2008 Retrospective I-II SMEC 48 3
Ditto et al. 2012 ITA 2003 - 2011 Prospective I-II SMEC 111 16
Garcia-Soto et al. 2012 USA 1993 - 2009 Retrospective I SMEC 86 25
Mahdi et al. 2013 USA 1988 - 2007 Retrospective I C 1359 a 61
Bachmann et al. 2014 DEU Not mentioned Retrospective I-II SMEC 75 6
Lee et al. 2014 KOR 1991 - 2010 Retrospective I-II SMEC 324 45
Mueller et al. 2016 USA 1994 - 2011 Retrospective I C 145 a 32
Gouy et al. 2017 FRA 1976 - 2016 Retrospective I M 68 7
Naru et al. 2017 IND 2014 - 2015 Prospective I-II SME 38 a 8
Minig et al. 2017 ESP 2000 - 2006 Retrospective I SME 163 a 25
Bogani et al. 2017 USA 1975 - 2016 Retrospective I-II SEC 290 42
Babayeva et al. 2018 DEU 2000 - 2014 Retrospective I-II SMEC 59 a 18
Padhy et al. 2018 USA 1998 - 2016 Retrospective I EC 85 4
Hengeveld et al. 2019 NLD/ DNK 2005 - 2017 Retrospective I SMEC 1234 393