Phase I/II enzyme gene polymorphisms and esophageal cancer risk: A meta-analysis of the literature

Table 2 Summary of the meta-analysis of CYP1A1, CYP2E1, GSTP1 and esophageal cancer risk.

Study	Country	Cases	Control	Cases wt/wt	Cases hetero1	Cases homo1	Control wt/wt1	Control hetero1	Control homo1	OR1 (95%CI)23	OR2 (95%CI)23	OR3 (95%CI)23
CYP1A1 Ile-Val:
Hori H	Japan	91	428	52	37	2	275	133	20	1.47 (0.89-2.41)	0.53 (0.06-2.29)	1.35 (0.83-2.19)
Nimura Y	China	89	137	50	26	13	92	38	7	1.26 (0.65-2.41)	3.42 (1.17-10.72)	1.59 (0.89-2.87)
Morita S	Japan	53	132	32	20	1	80	49	3	1.02 (0.49-2.08)	0.83 (0.02-10.84)	1.0 (0.5-1.9)
van Lieshout EM	Netherlands	34	247	26	8	0	207	37	3	1.72 (0.62-4.30)	0 (0-10.62)	1.59 (0.58-3.95)
Shao G	China	107	111	43	56	8	55	51	5	1.40 (0.78-2.53)	2.05 (0.54-8.49)	1.46 (0.83-2.59)
Wu M-T	Taiwan	146	324	68	62	16	179	127	18	1.34 (0.86-2.07)4	2.48 (1.15-5.34)4	1.42 (0.94-2.14)
Wang LD	China	62	38	30	28	4	20	16	2	1.17 (0.47-2.93)	1.33 (0.17-15.97)	1.19 (0.49-2.88)
Casson AG	Canada	45	45	45	0	0	45	0	0	NA6	NA6	NA6
Wang AH	China	127	101	21	56	50	31	48	22	1.72 (0.83-3.58)	3.35 (1.49-7.61)	2.24 (1.14-4.43)
Meta-analysis results		754	1563	367	293	94	984	499	80	1.37 (1.09-1.71)	2.52 (1.62-3.91)	1.44 (1.17-1.78)
CYP1A1 MspI:
Hori H	Japan	94	242	33	50	11	106	97	39	1.66 (0.96-2.88)	0.91 (0.38-2.06)	1.44 (0.86-2.44)
van Lieshout EM	Netherlands	34	247	22	12	0	207	37	3	3.05 (1.26-7.08)	0 (0-12.63)	2.82 (1.17-6.51)
Wu M-T	Taiwan	146	324	60	65	21	136	146	42	0.98 (0.63-1.53)4	1.24 (0.65-2.36)4	1.04 (0.68-1.57)
Casson AG	Canada	45	45	38	NA	NA	33	NA	NA	NA	NA	0.6 (0.2-1.8)4
Wang LD	China	62	38	33	25	4	12	22	4	0.41 (0.16-1.08)	0.36 (0.06-2.33)	0.41 (0.16-1.02)
Meta-analysis results		381	896	186	152	36	494	302	88	1.21 (0.64-2.32)	1.02 (0.62-1.68)	1.07 (0.64-1.80)
CYP2E1:
Hori H	Japan	79	633	49	24	6	412	202	19	1.00 (0.57-1.72)	2.66 (0.83-7.33)	1.14 (0.68-1.89)
Morita S	Japan	53	132	34	18	1	85	42	5	1.07 (0.51-2.22)	0.50 (0.01-4.72)	1.0 (0.5-2.0)
Lin DX	China	45	45	36	6	3	20	22	3	0.15 (0.04-0.48)	0.56 (0.07-4.59)	0.21 (0.08-0.56)4,5
Tan W	China	150	150	107	31	12	66	77	7	0.25 (0.14-0.43)	1.06 (0.36-3.34)	0.31 (0.24-0.40)4,5
Gao CM	China	93	196	55	31	7	121	62	13	1.13 (0.60-2.13)4	1.23 (0.40-3.77)4	1.15 (0.64-2.07)4
Meta-analysis results		420	1156	281	110	29	704	405	47	0.59 (0.28-1.23)	1.33 (0.72-2.44)	0.63 (0.30-1.30)
GSTP1:
Morita S	Japan	66	164	61	5	0	113	48	3	0.19 (0.07-0.52)	0 (0-4.6)	0.13 (0.04-0.45)5
Lin DX	China	42	36	29	12	1	22	11	3	0.83 (0.28-2.51)	0.25 (0.005-3.48)	0.7 (0.3-1.8)
van Lieshout EM	Netherlands	34	247	10	21	3	146	89	12	3.44 (1.47-8.55)	3.65 (0.56-16.82)	3.47 (1.51-8.46)
Lee JM	Taiwan	90	254	65	NA	NA	160	NA	NA	NA6	NA6	0.65 (0.39-1.11)4,5
Tan W	China	150	150	93	48	9	91	53	6	0.89 (0.53-1.48)	0.95 (0.58-1.55)	1.0 (0.8-1.3)
Wang LD	China	62	38	29	30	3	24	13	1	1.91 (0.76-4.89)	2.48 (0.18-135.66)	1.95 (0.79-4.87)4
Casson AG	Canada	45	45	19	22	4	26	12	7	2.5 (1.0-6.3)	0.8 (0.2-3.1)	1.8 (0.8-4.3)4
Meta-analysis results		489	934	306	138	20	582	226	32	1.17 (0.55-2.49)	1.02 (0.65-1.58)	1.01 (0.60-1.70)

¹“wt” allele was defined for each polymorphism as follows: the IIe allele for CYP1A1 IIe-Val and GSTP1 Ile-Val, the *1 allele for CYP1A1 MspI, and c1 for CYP2E1. Non-“wt” allele was defined as follows: the Val allele for CYP1A1 IIe-Val and GSTP1 Ile-Val, the *2 allele for CYP1A1 MspI and c2 for CYP2E1. “wt/wt”, “hetero”, and “homo” indicate homozygous for “wt” allele, heterozygous, and homozygous for non-“wt” allele, respectively.

²“wt/wt” was defined as the reference group and OR1, OR2, and OR3 for heterozygous, non-“wt” homozygous and the combination of heterozygous and non-“wt” homozygous groups.

³All the ORs were crude values calculated from the genotype distribution except in places denoted by^4,5.

⁴indicates cases where adjusted OR in the report was used and 5indicates where the OR value was inverted.

⁶NA: not available.