Table I.

Characteristics of the eligible studies included in the meta-analysis.

First author	Year	Country/Region	Ethnicity	Cancer type	Source of controls	Genotyping method	Cases	Controls	HWE
Goessl	1997	Germany	Caucasian	Colorectal cancer	PB	FLUPD	106	125	0.540
Paz-y-mino	2002	Ecuador	Mixed	Non-Hodgkin's lymphomas	HB	PCR-SSCP	22	50	0.009
Paz-y-mino	2003	Ecuador	Mixed	Lymphoma and leukemia	HB	PCR-SSCP	181	50	0.009
Hishida	2003	Japan	Asian	Non-Hodgkin's lymphomas	HB	PCR-RFLP	103	487	0.942
Kim	2004	Korea	Asian	Colorectal cancer	PB	TaqMan	107	330	0.091
Jung	2006	Korea	Asian	Lung cancer	PB	PCR-RFLP	432	432	0.613
Beiner	2006	Canada	Caucasian	Endometrial cancer	PB	MALDI-TOF	665	654	0.000
Song	2006	UK, Denmark, USA	Caucasian	Ovarian cancer	PB	TaqMan	1325	2044	0.411
Hsu	2007	Taiwan	Asian	Lung cancer	PB	PCR-RFLP	156	235	0.493
Raptisa	2007	Canada	Caucasian	Colorectal cancer	PB	TaqMan	929	1098	0.444
Raptisa	2007	Canada	Caucasian	Colorectal cancer	PB	TaqMan	430	275	0.195
Koessler	2008	UK	Caucasian	Colorectal cancer	PB	TaqMan	2294	2279	0.752
Tulupova	2008	Czech	Caucasian	Colorectal cancer	HB	TaqMan	611	608	0.689
Demokan	2010	Turkey	Mixed	Head and neck cancer	HB	PCR-RFLP	166	95	0.054

^aDifferent populations existed in one study. HWE, Hardy-Weinberg equilibrium. PB, population-based; HB, hospital-based. FLUPD, fluorescent-labeled universal primer; PCR, polymerase chain reaction; SSCP, single-strand conformation polymorphism; RFLP, restriction fragment length polymorphism; MALDI-TOF, matrix assisted laser desorption/ionization time-of-flight.