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.