Table 1. Main Characteristics of Included Studies in the Meta-Analysis.

First author	Year	Country	Cancer type	Genotyping	Source of control	-69G>A rs174538		4150G>T rs4246215
						Case AA/GA/GG	Control AA/GA/GG	Case TT/GT/GG	Control TT/GT/GG
Lv, Z.	2014	China	Breast cancer	PCR-RFLP	Community cancer-screening program for early detection of cancer	116/437/547	246/639/515	134/449/517	246/651/503
Chen, Y. D.	2013	China	Glioma	PCR-RFLP	Hospital	35/122/160	130/356/316	34/120/160	130/363/309
Liu, L.	2012	China	Hepatocellular carcinoma	PCR-RFLP	Community cancer-screening program for early detection of cancer	68/290/290	134/334/270	73/295/280	129/335/274
			Esophageal cancer			62/249/244	128/331/263	58/255/225	125/336/262
			Gastric cancer			41/182/189	76/209/169	42/177/183	76/212/166
			Colorectal cancer			28/104/104	54/144/109	27/102/100	52/145/109
Yang, M.	2009	China	Lung cancer	PCR-RFLP,TaqMan	Community nutritional survey, Community screening program for early detection of cancer and chronic noninfectious disease	253/796/791	354/880/724	271/815/754	358/883/717