Relationship between apurinic endonuclease 1 Asp148Glu polymorphism and gastrointestinal cancer risk: An updated meta-analysis

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

Ref.	Year	Country	Ethnicity	Cancer type	Genotyping method	Source of controls	Total sample size (cases/controls)
Zhang et al[10]	2014	China	Asian	CRC	PCR-CTPP	PB	247/300
Li et al[12]	2013	China	Asian	CRC	PCR-RFLP	HB	451/631
Canbay et al[13]	2011	Turkey	Caucasian	CRC	PCR-RFLP	PB	79/247
Gu et al[14]	2011	China	Asian	GC	PCR-RFLP	PB	572/547
Li et al[15]	2011	China	Asian	GC	PCR-RFLP	PB	126/156
Canbay et al[16]	2010	Turkey	Caucasian	GC	PCR-RFLP	PB	40/247
Brevik et al[17]	2010	United States	Caucasian	CRC	TaqMan	HB	304/359
Jelonek et al[18]	2010	Poland	Caucasian	CRC	PCR-RFLP	PB	153/273
Palli et al[19]	2010	Italy	Caucasian	GC	TaqMan	PB	314/548
Ye et al[20]	2010	China	Asian	CRC	MassARRAY	HB	123/158
Kasahara et al[21]	2008	Japan	Asian	CRC	PCR-RFLP	HB	68/121
Pardini et al[22]	2008	Czech	Caucasian	CRC	TaqMan	HB	532/532
Tse et al[23]	2008	United States	Caucasian	EC	TaqMan	HB	312/454
Berndt et al[24]	2007	United States	Caucasian	CRC	TaqMan	PB	720/725
Berndt et al[24]	2007	United States	Mixed	CRC	TaqMan	PB	47/48
Moreno et al[25]	2006	Spain	Caucasian	CRC	Arrayed primer extension	PB	359/312
Hao et al[26]	2004	China	Asian	EC	PCR-RFLP	PB	409/478

CRC: Colorectal cancer; GC: Gastric cancer; EC: Esophageal cancer; PCR-CTPP: Polymerase chain reaction with confronting two-pair primers; PCR-RFLP: Polymerase chain reaction-restriction fragment length polymorphism; PB: Population based; HB: Hospital based.

Table 2 Apurinic endonuclease 1 Asp148Glu polymorphism genotype distribution and allele frequency in cases and controls

Ref.	Genotype (n)								Allele frequency (n)				MAF
	Cases				Controls				Cases		Controls
	Total	TT	TG	GG	Total	TT	TG	GG	T	G	T	G
Zhang et al[10]	247	87	90	70	300	121	137	41	264	230	381	219	0.47
Li et al[12]	451	123	247	81	631	186	335	110	493	409	707	555	0.45
Canbay et al[13]	79	28	43	8	247	151	63	33	99	59	365	129	0.37
Gu et al[14]	338	69	185	84	362	110	183	69	323	353	403	321	0.52
Li et al[15]	126	26	64	36	156	56	70	30	116	136	182	130	0.54
Canbay et al[16]	40	14	18	8	247	151	63	33	46	34	365	129	0.42
Brevik et al[17]	304	102	137	65	359	108	167	84	341	267	383	335	0.44
Jelonek et al[18]	113	49	59	5	273	70	141	62	157	69	163	143	0.31
Palli et al[19]	298	103	147	48	546	208	243	95	353	243	659	433	0.41
Ye et al[20]	123	37	86	0	158	52	106	0	160	86	210	106	0.35
Kasahara et al[21]	68	23	45	0	121	70	51	0	91	45	191	51	0.33
Pardini et al[22]	531	140	261	130	530	157	267	106	541	521	581	479	0.49
Tse et al[23]	311	75	162	74	454	123	228	103	312	310	474	434	0.50
Berndt et al[24]	692	175	364	153	710	204	335	171	714	670	743	677	0.48
Berndt et al[24]	47	11	23	13	48	18	22	7	45	49	58	36	0.48
Moreno et al[25]	359	95	177	87	312	99	147	66	367	351	345	279	0.49
Hao et al[26]	409	126	211	72	477	149	243	95	463	355	541	433	0.43

MAF: Minor allele frequency.

Table 3 Meta-analysis results

Comparison	OR	95%CI	P value	Heterogeneity		Effects model
				I2	P value
G vs T	1.18	1.05-1.32	0.0041	71%	< 0.00001	Random
Caucasian	1.09	0.94-1.26	0.24	72%	0.0004	Random
Asian	1.27	1.07-1.51	0.0071	70%	0.003	Random
Colorectal cancer	1.15	0.99-1.33	0.06	73%	< 0.0001	Random
Gastric cancer	1.41	1.09-1.83	0.0091	70%	0.02	Random
Esophageal cancer	1.01	0.88-1.16	0.87	0%	0.40	Fixed
GG vs TT	1.25	0.98-1.59	0.07	73%	< 0.00001	Random
Caucasian	1.04	0.77-1.41	0.81	72%	0.0003	Random
Asian	1.58	1.05-2.38	0.031	76%	0.002	Random
Colorectal cancer	1.12	0.79-1.59	0.51	79%	< 0.00001	Random
Gastric cancer	1.77	1.11-2.84	0.021	63%	0.04	Random
Esophageal cancer	1.02	0.77-1.35	0.90	0%	0.34	Fixed
TG vs TT	1.28	1.08-1.52	0.0041	68%	< 0.0001	Random
Caucasian	1.26	0.98-1.63	0.07	76%	<0.0001	Random
Asian	1.30	1.01-1.67	0.041	63%	0.01	Random
Colorectal cancer	1.23	0.98-1.54	0.08	73%	< 0.0001	Random
Gastric cancer	1.66	1.20-2.31	0.0021	51%	< 0.0001	Random
Esophageal cancer	1.04	0.83-1.31	0.72	0%	0.41	Fixed
GG+TG vs TT	1.32	1.10-1.57	0.0021	73%	< 0.00001	Random
Caucasian	1.24	0.95-1.61	0.11	80%	< 0.00001	Random
Asian	1.38	1.07-1.78	0.011	66%	0.007	Random
Colorectal cancer	1.23	0.98-1.55	0.08	75%	< 0.0001	Random
Gastric cancer	1.77	1.40-2.24	< 0.00011	19%	0.29	Fixed
Esophageal cancer	1.02	0.81-1.29	0.84	9%	0.29	Fixed
GG vs TT+TG	1.10	0.90-1.34	0.33	70%	< 0.0001	Random
Caucasian	0.95	0.75-1.20	0.66	64%	0.004	Random
Asian	1.36	0.95-1.95	0.10	77%	0.002	Random
Colorectal cancer	1.05	0.77-1.43	0.76	79%	< 0.00001	Random
Gastric cancer	1.25	0.99-1.56	0.06	33%	0.21	Fixed
Esophageal cancer	0.96	0.75-1.21	0.71	0%	0.38	Fixed

¹Represent a significant association between APE1 Asp148Glu polymorphism and GI cancer risk in three genetic models in the overall population.