Table 1.

Characteristics of studies included in the meta-analysis.

Surname (ref)	Year	Country	Ethnicity	Cancer type	Control source	Genotype method	Case				Control				MAF	HWE	Score
							Val/Val	Val/Ala	Ala/Ala	All	Val/Val	Val/Ala	Ala/Ala	All
Ambrosone et al. [60]	1999	USA	Caucasian	Breast	PB	PCR-RFLP	16	53	45	114	25	62	23	110	0.49	0.181	12
Mitrunen et al. [10]	2001	Finland	Caucasian	Breast	PB	PCR-RFLP	124	255	100	479	153	231	98	482	0.44	0.526	13
Wang et al. [7]	2001	USA	Caucasian	Lung	HB	Pyrosequencing	305	551	245	1101	288	628	323	1239	0.49	0.609	9
Green et al. [61]	2002	UK	Caucasian	Breast	HB	PCR-RFLP	13	17	9	39	8	22	6	36	0.47	0.175	5
Hirvonen et al. [62]	2002	Finland	Caucasian	MPM	PB	PCR-RFLP	6	11	3	20	15	36	12	63	0.48	0.248	9
Levine et al. [63]	2002	USA	Mixed	CRC	PB	PCR-RFLP	139	209	108	456	140	234	121	495	0.48	0.237	12
Li et al. [64]	2002	USA	Caucasian	Pancreatic	PB	PCR-RFLP	10	11	3	24	8	10	5	23	0.43	0.580	6
Stoehlmacher et al. [13]	2002	USA	Caucasian	CRC	PB	TaqMan	25	65	35	125	21	64	37	122	0.43	0.456	5
Egan et al. [16]	2003	USA	Caucasian	Breast	PB	PCR-RFLP	102	250	118	470	130	240	127	497	0.50	0.446	10
Lin et al. [65]a	2003	China	Asian	Lung	HB	PCR-RFLP	139	59 (Val/Ala + Ala/Ala)		198	233	99 (Val/Ala + Ala/Ala)		332	NA	NA	10
Woodson et al. [66]	2003	USA	Caucasian	Prostate	PB	MALDI-TOF MS	43	98	58	199	49	102	40	191	0.48	0.330	12
Cai et al. [11]	2004	China	Asian	Breast	PB	PCR-RFLP	831	266	28	1125	884	290	23	1197	0.14	0.890	15
Hung et al. [8]	2004	Italy	Caucasian	Bladder	HB	PCR-RFLP	68	89	44	201	45	115	54	214	0.48	0.262	9
Ichimura et al. [67]	2004	Japan	Asian	Bladder	HB	PCR-RFLP	169	41	3	213	157	48	4	209	0.13	0.882	11
Knight et al. [68]	2004	Canada	Caucasian	Breast	PB	PCR-SSCP	107	187	105	399	90	195	87	372	0.50	0.350	14
Lan et al. [17]	2004	China	Asian	Lung	PB	Real-time PCR	93	23	3	119	81	30	1	112	0.14	0.321	10
Millikan et al. [69]	2004	USA	African	Breast	PB	TaqMan	259	372	129	760	196	357	124	677	0.45	0.083	13
Millikan et al. [69]	2004	USA	Caucasian	Breast	PB	TaqMan	273	681	311	1265	266	586	283	1135	0.49	0.269	13
Olson et al. [70]	2004	USA	Caucasian	Ovarian	HB	MALDI-TOF MS	27	64	27	118	51	87	39	177	0.47	0.869	9
Tamimi et al. [71]	2004	USA	Caucasian	Breast	PB	Mixedd	255	468	245	968	297	612	296	1205	0.50	0.584	15
Bergman et al. [9]	2005	Sweden	Caucasian	Breast	PB	Sequencing	33	73	12	118	43	88	43	174	0.50	0.879	11
Cheng et al. [72]	2005	China	Asian	Breast	HB	MassARRAY	343	115	11	469	545	183	11	739	0.14	0.322	11
Gaudet et al. [38]	2005	USA	Caucasian	Breast	PB	MALDI-TOF MS	253	511	270	1034	264	539	281	1084	0.49	0.862	14
Landi et al. [73]	2005	Spain	Caucasian	CRC	HB	APEX	94	164	77	335	88	151	64	303	0.46	0.958	5
Li et al. [74]	2005	USA	Caucasian	Prostate	PB	PCR-RFLP	132	288	147	567	190	379	195	764	0.50	0.829	14
Terry et al. [75]	2005	USA	Caucasian	Bladder	HB	MALDI-TOF MS	54	122	59	235	57	103	54	214	0.49	0.586	8
Ho et al. [18]c	2006	China	Asian	Lung	HB	PCR-RFLP	176	58	0	234	180	52	7	239	0.14	0.184	7
Lightfoot et al. [76]	2006	USA and UK	Caucasian	NHL	PB	TaqMan	211	463	229	903	358	713	371	1442	0.50	0.676	13
Slanger et al. [77]	2006	Germany	Caucasian	Breast	PB	TaqMan	144	318	152	614	263	528	289	1080	0.49	0.477	14
Wang et al. [78]	2006	USA	Mixed	NHL	PB	TaqMan	285	545	290	1120	240	486	211	937	0.48	0.240	13
Cengiz et al. [15]b	2007	Turkey	Caucasian	Bladder	HB	PCR-RFLP	34 (Val/Val + Val/Ala)		17	51	34 (Val/Val + Val/Ala)		19	53	NA	NA	7
Choi et al. [37]	2007	USA	Caucasian	Prostate	PB	MALDI-TOF MS	112	239	104	455	293	610	311	1214	0.49	0.857	13
Choi et al. [37]	2007	USA	African	Prostate	PB	MALDI-TOF MS	7	15	6	28	39	52	31	122	0.47	0.112	10
Ergen et al. [79]c	2007	Turkey	Caucasian	Prostate	HB	PCR-RFLP	19	25	6	50	32	18	0	50	0.18	0.121	7
Han et al. [80]	2007	USA	Caucasian	Skin	PB	TaqMan	184	402	187	773	196	425	212	833	0.49	0.549	15
Johnatty et al. [81]	2007	Australia	Caucasian	Ovarian	PB	Real-time PCR	123	273	147	543	276	546	308	1130	0.49	0.269	11
Kang et al. [82]	2007	USA	Caucasian	Prostate	PB	TaqMan	275	578	297	1150	376	686	320	1382	0.48	0.835	13
Kang et al. [82]	2007	USA	African	Prostate	PB	TaqMan	31	57	15	103	122	194	79	395	0.45	0.906	11
Landi et al. [83]	2007	Italy	Caucasian	MPM	HB	APEX	16	27	37	80	98	170	81	349	0.48	0.661	9
di Martino et al. [84]	2007	USA	Caucasian	Esophageal	HB	PCR-RFLP	32	73	35	140	20	39	34	93	0.42	0.171	8
Murphy et al. [12]	2007	Ireland	Caucasian	Esophageal	PB	SNaPshot	44	103	60	207	60	113	48	221	0.47	0.703	11
Arsova-Sarafinovska et al. [85]	2008	Turkey	Caucasian	Prostate	HB	Real-time PCR	19	46	20	85	41	73	37	151	0.49	0.690	9
Cooper et al. [86]	2008	USA	Caucasian	Prostate	PB	TaqMan	602	1352	680	2634	423	789	424	1636	0.50	0.152	15
Dalan et al. [87]	2008	Turkey	Caucasian	Ovarian	PB	PCR-RFLP	30	19	6	55	28	17	6	51	0.28	0.196	7
Justenhoven et al. [88]	2008	Germany	Caucasian	Breast	PB	MALDI-TOF MS	159	312	133	604	163	313	145	621	0.49	0.824	14
Mikhak et al. [89]	2008	USA	Caucasian	Prostate	PB	TaqMan	156	320	166	642	162	331	159	652	0.50	0.695	14
Rajaraman et al. [90]	2008	USA	Caucasian	Brain	HB	TaqMan	129	262	123	514	122	220	109	451	0.49	0.617	10
Wheatley-Price et al. [91]	2008	USA	Caucasian	Pancreatic	HB	TaqMan	33	58	31	122	61	165	105	331	0.43	0.786	11
Zienolddiny et al. [92]	2008	Norway	Caucasian	Lung	PB	APEX	74	175	70	319	119	178	78	375	0.45	0.448	12
Eras-Erdogan et al. [93]	2009	Turkey	Caucasian	Breast	PB	PCR-RFLP	107	113	30	250	150	141	39	330	0.33	0.508	8
Funke et al. [94]	2009	Germany	Caucasian	CRC	PB	Pyrosequencing	136	321	166	623	146	294	163	603	0.49	0.554	12
Iguchi et al. [95]	2009	USA	Mixed	Prostate	HB	PCR-RFLP	41	86	60	187	40	96	39	175	0.50	0.199	6
Kostrykina et al. [96]	2009	Russia	Caucasian	Breast	PB	TaqMan	123	233	119	475	103	183	90	376	0.48	0.622	12
Tong et al. [14]a	2009	Korea	Asian	Cervical	HB	SNaPshot	72	27 (Val/Ala + Ala/Ala)		99	194	69 (Val/Ala + Ala/Ala)		263	NA	NA	7
Ermolenko et al. [97]	2010	Russia	Caucasian	Breast	HB	Real-time PCR	228	454	239	921	121	235	104	460	0.48	0.620	9
Ezzikouri et al. [98]	2010	Morocco	Caucasian	HCC	PB	PCR-RFLP	21	45	30	96	81	101	40	222	0.41	0.388	11
Ibrahim et al. [99]	2010	Egypt	African	HCC	HB	PCR-RFLP	16	32	27	75	19	28	11	58	0.43	0.904	8
Kim et al. [100]	2010	Korea	Asian	Breast	HB	TaqMan	234	66	4	304	279	90	7	376	0.14	0.934	11
Méplan et al. [101]	2010	Czech	Caucasian	CRC	HB	AS-PCR	172	358	189	719	165	318	174	657	0.49	0.415	9
Tang et al. [102]	2010	USA	Mixed	Pancreatic	HB	TaqMan	143	278	137	558	167	309	162	638	0.50	0.429	11
Wu et al. [103]	2010	China	Asian	Oral	HB	Real-time PCR	91	28	2	121	88	32	2	122	0.15	0.637	9
Yi et al. [104]	2010	China	Asian	Gastric	HB	SNaPshot	85	48	7	140	119	27	1	147	0.10	0.690	9
Cerne et al. [105]	2011	Slovenia	Caucasian	Breast	HB	TaqMan	118	269	143	530	65	134	71	270	0.51	0.910	8
Cheng et al. [106]b	2011	USA	Mixed	Prostate	PB	MALDI-TOF MS	152 (Val/Val + Val/Ala)		50	202	1054 (Val/Val + Val/Ala)		374	1428	NA	NA	13
Mohelnikova-Duchonova et al. [107]	2011	Czech	Caucasian	Pancreatic	PB	Real-time PCR	66	121	48	235	73	134	58	265	0.47	0.812	10
Zhang et al. [108]b	2011	USA	Mixed	Pancreatic	PB	TaqMan	129 (Val/Val + Val/Ala)		60	189	365 (Val/Val + Val/Ala)		121	486	NA	NA	13
Atoum et al. [109]c	2012	Jordan	Caucasian	Breast	HB	PCR-RFLP	22	43	0	65	11	6	0	17	0.18	0.377	6
Farawela et al. [110]	2012	Egypt	African	NHL	PB	PCR-RFLP	10	50	40	100	12	49	39	100	0.37	0.568	9
Hemelrijck et al. [111]	2012	Germany	Caucasian	Prostate	PB	MassARRAY	50	100	53	203	80	190	90	360	0.49	0.285	13
Kucukgergin et al. [112]	2012	Turkey	Caucasian	Bladder	HB	PCR-RFLP	52	68	37	157	89	99	36	224	0.38	0.341	8
Kucukgergin et al. [113]	2012	Turkey	Caucasian	Prostate	HB	PCR-RFLP	43	65	26	134	66	69	24	159	0.37	0.398	8
Tsai et al. [114]a	2012	China	Asian	Breast	HB	Real-time PCR	192	68 (Val/Ala + Ala/Ala)		260	138	86 (Val/Ala + Ala/Ala)		224	NA	NA	8
Ye et al. [115]	2012	China	Asian	NPC	HB	PCR	88	15	2	105	110	23	3	136	0.11	0.191	8
Zhao et al. [116]	2012	China	Asian	Brain	HB	OpenArray	241	107	31	379	293	81	6	380	0.12	0.882	11
Amr et al. [117]	2013	Egypt	African	Bladder	PB	TaqMan	127	188	99	414	109	160	87	356	0.47	0.065	13
Ashour et al. [118]	2013	Egypt	African	Lung	PB	TaqMan	17	27	6	50	21	25	4	50	0.33	0.355	9
Attatippaholkun and Wikainapakul [119]	2013	Thailand	Asian	Cervical	HB	SNaPshot	64	39	4	107	84	48	3	135	0.20	0.184	7
Attatippaholkun et al. [119]	2013	Thailand	Asian	Breast	HB	SNaPshot	82	54	5	141	84	48	3	135	0.20	0.184	7
Eken et al. [120]	2013	Turkey	Caucasian	Prostate	HB	Real-time PCR	7	17	9	33	31	37	13	81	0.39	0.726	8
Han et al. [121]	2013	Korea	Asian	Pancreatic	PB	PCR-SSCP	190	85	19	294	236	59	5	300	0.12	0.558	12
Méplan et al. [122]	2013	Denmark	Caucasian	Breast	PB	TaqMan	228	485	226	939	237	494	227	958	0.49	0.331	14
Atilgan et al. [123]	2014	Turkey	Caucasian	RCC	HB	Probe	10	17	14	41	23	19	8	50	0.35	0.244	5
Liu et al [124]	2014	China	Asian	OSCC	HB	PCR-RFLP	272	83	7	362	296	61	1	358	0.09	0.243	10
Oskina et al. [125]	2014	Russia	Caucasian	Prostate	PB	TaqMan	92	194	94	380	86	152	99	337	0.48	0.076	12
Brown et al. [126]	2015	USA	Mixed	Medulloblastoma	PB	Illumina SNP chip	3	15	8	26	18	18	9	45	0.40	0.264	5
Jablonska et al. [127]	2015	Polish	Caucasian	Breast	PB	Real-time PCR	32	75	29	136	41	92	50	183	0.48	0.915	10
Parlaktas et al. [128]	2015	Turkey	Caucasian	Prostate	HB	Probe	23	23	3	49	24	20	5	49	0.31	0.784	7
Su et al. [129]	2015	China	Asian	HCC	HB	PCR-RFLP	334	78	10	422	359	107	13	479	0.14	0.150	7

MAF: minor allele frequency; HWE: Hardy-Weinberg equilibrium; HB: hospital-based; PB: population based; NA, not applicable; PCR-RFLP: polymorphism chain reaction-restriction fragment length polymorphism; MALDI-TOF MS: matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry; PCR-SSCP: polymorphism chain reaction-single strand conformation polymorphism; APEX: arrayed primer extension; AS-PCR: allele specific-polymorphism chain reaction; MPM: malignant pleural mesothelioma; CRC: colorectal cancer; NHL: non-Hodgkin's lymphoma; HCC: hepatocellular carcinoma; RCC: renal cell carcinoma; OSCC: oral squamous cell carcinoma. ^aLin et al. [65], Tong et al. [14], and Tsai et al. [114] were only calculated for the dominant model. ^bCengiz et al. [15], Cheng et al. [106], and Zhang et al. [108] were only calculated for the recessive model. ^cHo et al. [18], Ergen et al. [79], and Atoum et al. [109] were only calculated for the heterozygous model, dominant model, and allele comparison, and the number of Ala/Ala genotype was zero. ^dMixed: which included more than one genotyping methods.