CYP2E1 PstI/RsaI polymorphism and colorectal cancer risk: A meta-analysis

Table 1 Main characteristics of studies included in this meta-analysis

Author, yr	Ethnicity (country)	Source of controls	Matching criteria	Sample size (case/control)	Genotype (case/controls)			HWE
					c1c1	c2c2	c1c2 + c2c2
Butler et al[9], 2001	Caucasian (Australian)	Population-based	Age, sex	219/200	147/194	NA/NA	2/6	NA
Le Marchand et al[10], 2002	Mixed (Japanese, Caucasian, Hawaiian)	Population-based	Age, sex, ethnicity	521/639	384/449	21/26	137/190	No1
Yu et al[11], 2004	Asian (Chinese )	Population-based	Cancer-free	126/343	69/209	3/8	57/129	Yes
Landi et al[12], 2005	Caucasian (Spanish)	Hospital-based	Cancer-free	377/326	323/283	1/1	18/16	Yes
van der Logt et al[13], 2006	Caucasian (Netherlander)	Population-based	Age > 18-yr, without (family) history of CRC	371/415	333/389	1/2	24/23	Yes
Kiss et al[14], 2007	Caucasian (Hungarian)	Both	Age, sex, red meat intake, smoking	500/500	428/456	7/2	72/44	Yes
Küry et al[15], 2007	Caucasian (French)	Population-based	Age, sex	1023/1121	940/1027	6/1	73/91	Yes
Gao et al[16], 2007	Asian (Chinese )	Population-based	Age, sex, ethnicity	315/439	185/266	22/13	128/167	Yes
Cotterchio et al[17], 2008	Caucasian (Canadian )	Population-based	Age, sex	842/1251	784/1162	0/0	48/85	Yes
Morita et al[18], 2009	Asian (Japanese )	Population-based	Sex, smoking, red meat intake, residence area	685/778	412/455	36/44	273/323	Yes

¹The deviation from HWE was allowed in mixed control populations. HWE: Hardy-Weinberg equilibrium; NA: Not available.