Table 1. Characteristics of studies included in the meta-analysis.

No.	Study	Year	Ethnicity	Cancer type	Source of controll†	Genotyping method	HWE control		Case				Control
									TT	CT	CC		TT	CT	CC
1	Min KT [24]	2011	Asian	colorectral	PB	PCR-RFLP	0.633		125	201	120		148	254	100
2	Zhang M [25]	2011	Asian	breast	PB	PCR-RFLP	0.904		148	89	11		133	93	17
3	Zhan JF [26]	2011	Asian	colorectral	HB	PCR-RFLP	0.849		56	128	68		163	267	113
4	Zhou B [27]	2011	Asian	squamous cell cancer	HB	PCR-RFLP	0.077		57	123	46		82	169	58
5	Hong YS [14]	2011	Asian	lung	HB	TaqMan	0.163		96	224	86		134	198	96
6	Zhang XW [28]	2011	Asian	hepatocellular	PB	PIRA-PCR	0.52		277	449	208		477	817	328
7	Zhu LJ [29]	2011	Asian	colorectral	NC	TaqMan	0.79		130	303	140		172	295	121
8	Chen H [30]	2011	Asian	colorectral	HB	PCR-LDR	0.788		35	64	27		107	206	94
9	Okubo M [31]	2010	Asian	gastric	HB	PCR-RFLP	0.51		166	281	105		223	350	124
10	Dou T [17]	2010	Asian	glioma	HB	PCR-LDR	0.119		189	343	111		208	305	143
11	Wang K [32]	2010	Asian	esophageal	NC	SNaPshot	0.6		48	262	148		111	250	128
12	Peng S [18]	2010	Asian	gastric	HB	PCR-RFLP	0.936		43	94	76		50	107	56
13	Qi P [33]	2010	Asian	hepatocellcular	NC	PCR-LDR	0.793		159	286	115		102	197	92
14	Tian T [15]	2009	Asian	lung	PB	PCR-RFLP	0.7		293	512	253		307	519	209
15	Hu Z [34]	2009	Asian	breast	PB	PCR-RFLP	0.207		287	483	239		358	517	218
16	Li XD [22]	2010	Asian	hepatocellcular	HB	PCR-RFLP	0.402		82	150	78		78	102	42
17	Kim JM [35]	2010	Asian	lung	PB	PCR-MCS	0.6		162	305	187		185	300	155
18	Jedlinski DJ [36]	2011	Caucasion	breast	PB	PCR-RFLP	0.83		33	86	68		31	82	58
19	Akkiz H [23]	2011	Caucasion	hepatocellular	HB	PCR-RFLP	0.492		22	86	77		40	87	58
20	Mittal RD [37]	2011	Caucasion	bladder	HB	PCR-RFLP	0.003		5	131	76		14	127	109
21	George GP [38]	2011	Caucasion	prostate	PB	PCR-RFLP	0.002		3	101	55		10	114	106
22	Liu Z [20]	2010	Caucasion	head and neck	HB	PCR-RFLP	0.737		194	565	350		202	545	383
23	Srivastava K [19]	2010	Caucasion	gallbladder	PB	PCR-RFLP	0.068		16	95	119		19	75	136
24	Catucci I [39]	2010	Caucasion	breast	NC	TaqMan	0.708		244	842	766		377	1246	1116
25	Hoffman AE [16]	2009	Caucasion	breast	NC	Sequenom MassARRAY	0.583		36	209	181		71	229	166
26	Ye Y [21]	2008	Caucasion	esophageal	HB	SNPlex assay	0.477		83	141	83		59	172	107
27	Vinci S [40]	2011	Caucasion	lung	NC	HRMA	0.267		12	54	35		10	61	58

†, HB:hospital-based; PB:population-based; NC:not clear.