Meta-analysis of immunohistochemical expression of hypoxia inducible factor-1α as a prognostic role in gastric cancer

Table 1 Characteristics of the included studies

Ref.	Country of origin	Sample size (M/F, n)	Mean/median age (yr)	Study quality (points)	5-yr OS rate analysis	Expression rate
Zhan et al[9]	China	60 (38/22)	56.5	6/9	Reported	58.3%
Lu et al[10]	China	68 (43/25)	49.86	5/9	NR	52.9%
Isobe et al[11]	Japan	128 (91/37)	67.3	6/9	Reported	65.6%
Qiu et al[12]	China	188 (127/61)	57	6/9	Reported	54.6%
Oh et al[13]	South Korea	114 (67/47)	59	5/9	NR	15.8%
Kolev et al[14]	Japan	152 (110/42)	59.5	6/9	Reported	62.5%
Cabuk et al[15]	Turkey	51 (30/21)	63	4/9	NR	71%
Sumiyoshi et al[16]	Japan	216 (148/68)	65.2	5/9	NR	39.4%/85
Mizokami et al[17]	Japan	126 (83/41)	65.3	6/9	Reported	38.9%

Study quality was listed using the results of the Newcastle -Ottawa questionnaire. M: Male; F: Female; NR: Not reported; OS: Overall survival.