HIF-1α -1790G>A polymorphism significantly increases the risk of digestive tract cancer: A meta-analysis

Table 1 Baseline characteristics of eligible studies

Ref.	Year	Country	Ethnicity	Control	Cancer type	SNP	Cases	Controls
Alves et al[21]	2012	Brazil	Latin America	HB	Oral cancer	C1722T, G1790A	40	88
Ruiz-Tovar et al[22]	2012	Spain	Caucasian	PB	Pancreatic cancer	C1722T, G1790A	59	159
Wang et al[7]	2009	China	Asian	HB	Pancreatic cancer	C1722T, G1790A	263	271
Kang et al[15]	2011	Korea	Asian	HB	Colorectal cancer	C1722T	50	50
Shieh et al[24]	2010	China	Asian	HB	Oral cancer	C1722T, G1790A	305	96
Hsiao et al[25]	2010	China	Asian	HB	Hepatocellular carcinoma	C1722T, G1790A	102	347
Knechtel et al[17]	2010	Austria	Caucasian	HB	Colorectal cancer	C1722T, G1790A	381	1209
Chen et al[26]	2009	China	Asian	PB	Oral cancer	C1722T, G1790A	347	174
Li et al[16]	2009	China	Asian	HB	Gastric cancer	C1722T, G1790A	87	106
Muñoz-Guerra et al[27]	2009	Spain	Caucasian	PB	Oral cancer	C1722T, G1790A	155	139
Fransén et al[28]	2006	Sweden	Caucasian	HB	Colorectal cancer	C1722T, G1790A	198	258
Ling et al[29]	2005	China	Asian	PB	Esophageal cancer	C1722T	95	104
Kuwai et al[30]	2004	Japan	Asian	PB	Colorectal cancer	C1722T	100	100

HB: Hospital-based studies; PB: Population-based studies; SNP: Single nucleotide polymorphism.