Table 1

Summary of case–control studies on GSTM1, GSTT1, GSTP1 (ILE105VAL), and CYP1A1 (ILE462VAL) genotypes and head and neck cancers

Ref.	First author	Year of publication	Country	Control source	Matching	Site
Ref.	First author	Year of publication	Country	Control source	Matching				Oral	Pharynx	Larynx
(13)	Buch	2002	India	Hospital-healthy	Individual	X
(14)	Cheng	1999	United States	Hospital	Individual	Head & neck; site NS
(15)	Coutelle	1997	France	Alcoholism clinic	None		X	X
(16)	Deakin	1996	United Kingdom	Hospital	None	X
(17)	Gonzalez	1998	Spain	Hospital-healthy	None	X	X	X
(18)	Gronau	2003	Germany	Hospital-healthy	Individual	X	X	X
(19)	Hahn	2002	Germany	Hospital-healthy	Individual	X
(20)	Hamel	2000	Canada	Mixed	Individual	X	X	X
(21)	Hanna	2001	United States	Hospital	Individual			X
(22)	Hong	2000	Korea	Hospital	None			X
(23)	Hung	1997	Taiwan	Population based	Frequency	X
(24)	Jaskula-Sztul	1998	Poland	NS, healthy	None			X
(25 , 26)	Jourenkova	1999	France	Hospital	Frequency	X	X	X
(26 , 27)	Jourenkova	1999	France	Hospital	Frequency	X	X	X
(28)	Kao	2002	Taiwan	Hospital	None	X
(29)	Katoh	1999	Japan	Hospital-healthy	None	X
(30)	Katoh	1999	Japan	Hospital-healthy	None	X
(31)	Kietthubthew	2001	Thailand	Population based	Individual	X
(32)	Kihara	1997	Japan	Hospital-healthy	None	X	X	X
(33)	Ko	2001	Germany	Hospital-healthy	None	Head & neck; site NS
(34)	Matthias	1998	Germany	Hospital	None	X	X	X
(35)	Matthias	1999	Germany	Hospital	None	X	X	X
(36)	McWilliams	2000	United States	Hospital	None	X	X	X
(37)	Morita	1999	Japan	Hospital-healthy	None	X	X	X
(38)	Nomura	2000	Japan	Hospital	None	X	X
(39)	Olshan	2000	United States	Hospital	Frequency	X	X	X
(40)	Oude Ophuis	1998	Netherlands	Hospital-healthy	None	X	X	X
(41)	Oude Ophuis	2003	Netherlands	Hospital-healthy	None	X	X	X
(42)	Park	1997	United States	Hospital	Frequency	X	X	X
(43)	Park	1999	United States	Hospital	Frequency	X	X	X
(44)	Park	2000	United States	Hospital	Frequency	X	X	X
(45)	Risch	2003	Germany	Population based	Frequency			X
(46)	Sato	2000	Japan	Hospital-healthy	None	X
(47)	Sreelekha	2001	India	Hospital-healthy	Individual	X
(48)	Tanimoto	1999	Japan	Hospital	Individual	X
(49)	To-Figueras	2002	Spain	Hospital-healthy	None			X
(50)	Trizna	1995	United States	Hospital-healthy	None	X	X	X
No. of studies in meta-analysis
Cases
Controls
Summary OR (95% CI)
Test for heterogeneity
Publication bias (Egger’s test)