Table 2 Subgroup meta-analyses of CYP1A2 SNPs and cancer risk according to study design, ethnicity and tumour site

rs762551

3373/4006

29,808/36,562

1.03

0.96–1.12

50.4

<0.01

Study design

 Hospital based

1048/1110

8289/8482

1.03

0.88–1.20

60.3

<0.01

 Population based

2314/2869

21,326/27,820

1.05

0.96–1.15

41.8

<0.01

Study sample size

 Large

2883/3387

27,381/32,680

1.02

0.94–1.11

55.9

<0.01

 Small

490/619

2427/3882

1.09

0.90–1.32

36.0

0.05

Ethnicity

 Asian

348/414

2539/2874

0.95

0.72–1.27

54.6

0.02

 Caucasian

2132/2600

18,305/23,388

1.03

0.94–1.13

42.4

<0.01

 Mixed

893/992

8964/10,300

1.05

0.89–1.25

62.8

<0.01

Tumour site

 Bladder

392/436

3038/2806

0.84

0.70–1.01

28.5

0.23

 Breast

1097/1280

10,285/13,269

1.17

0.94–1.45

79.2

<0.01

 Colorectum

803/934

7755/9199

1.03

0.93–1.14

0.0

0.56

 Endometrium

258/391

1095/1898

1.06

0.87–1.30

0.0

0.85

 Liver

12/26

235/330

0.63

0.30–1.32

5.0

0.31

 Lung

221/265

1536/2446

1.20

0.87–1.64

58.9

0.01

 Ovaries

27/34

349/478

1.31

0.33–5.19

80.3

0.01

 Pancreas

107/142

1296/1656

1.04

0.80–1.36

0.0

0.87

 Stomach

46/141

425/1258

0.85

0.59–1.21

0.0

0.45

 UADT

186/192

1670/1631

0.97

0.73–1.29

29.9

0.23

Exposed

Not exposed

OR

95 % CI

I² (%)

P value for heterogeneity

rs2069514

1229/1373

3333/5026

0.99

0.81–1.21

60.0

<0.01

Study design

 Hospital based

758/783

1727/2329

1.01

0.73–1.40

73.7

<0.01

 Population based

471/590

1606/2697

0.94

0.78–1.14

10.6

0.35

Study sample size

 Large

969/1085

2691/3736

0.97

0.86–1.09

0.0

0.89

 Small

260/288

642/1290

1.18

0.65–2.11

81.1

<0.01

Ethnicity

 Asian

1093/1235

1297/1388

0.96

0.86–1.07

0.0

0.86

 Caucasian

136/138

2036/3638

1.16

0.63–2.14

75.7

<0.01

Tumour site

 Bladder

236/237

352/326

0.92

0.73–1.17

0.0

0.81

 Colorectum

447/458

836/847

0.96

0.65–1.43

53.2

0.07

 Liver

315/409

324/393

0.94

0.76–1.15

0.0

0.68

 Lung

211/219

1397/1881

1.16

0.68–1.99

76.3

<0.01

Exposed

Not exposed

OR

95 % CI

I² (%)

P value for heterogeneity

rs2069526

139/202

1486/2144

0.94

0.70–1.26

20.7

0.27

Study design

 Hospital based

35/78

706/1236

0.89

0.47–1.72

53.9

0.09

 Population based

104/124

780/908

0.94

0.71–1.25

0.0

0.59

Study sample size

 Large

121/151

1137/1181

0.85

0.56–1.28

49.4

0.12

 Small

18/51

349/963

1.29

0.71–2.35

0.0

0.89

Ethnicity

 Caucasian

139/202

1486/2144

0.94

0.70–1.26

20.7

0.27

Tumour site

 Colorectum

74/93

737/788

0.91

0.66–1.26

0.0

0.40

 Lung

60/75

676/811

0.90

0.47–1.71

55.4

0.08

Exposed

Not exposed

OR

95 % CI

I² (%)

P value for heterogeneity

rs2470890

1106/1187

4559/5538

1.11

0.96–1.28

39.0

0.09

Study design

 Hospital based

429/480

2594/3069

1.10

0.95–1.27

0.0

0.46

 Population based

655/670

1783/2219

1.09

0.80–1.50

70.5

0.02

Study sample size

 Large

1077/1043

4390/4714

1.11

0.94–1.30

50.9

0.04

 Small

29/144

169/824

1.07

0.69–1.66

0.0

0.85

Ethnicity

 Asian

28/42

873/975

0.77

0.37–1.64

55.4

0.13

 Caucasian

863/957

2904/3525

1.07

0.96–1.20

0.0

0.47

 Mixed

215/188

782/1038

1.44

1.16–1.80

0.0

0.41

Tumour site

 Breast

222/189

866/1025

1.17

0.65–2.08

73.4

0.05

 Colorectum

500/509

866/929

1.10

0.94–1.28

0.0

0.51

 Lung

48/77

348/520

0.92

0.63–1.37

0.0

0.47

 UADT

294/262

1535/1528

1.20

0.83–1.74

65.7

0.09

Exposed

Not exposed

OR

95 % CI

I² (%)

P value for heterogeneity

rs2472304

127/172

975/1107

0.84

0.64–1.09

0.0

0.43

Study design

 Population based

85/120

261/395

0.82

0.51–1.30

40.4

0.20

Study sample size

 Large

112/136

878/846

0.79

0.59–1.05

0.0

0.41

Ethnicity

 Caucasian

92/121

346/383

0.72

0.52–0.99

0.0

0.61

Tumour site

 Breast

42/52

714/712

0.94

0.61–1.45

0.0

0.43

Exposed

Not exposed

OR

95 % CI

I² (%)

P value for heterogeneity

rs35694136

439/419

839/1183

1.37

0.78–2.42

89.0

<0.01

Study design

 Hospital based

290/263

373/379

1.46

0.56–3.77

92.7

<0.01

 Population based

149/156

466/804

1.28

0.77–2.13

68.4

0.08

Study sample size

 Large

290/319

632/970

1.11

0.75–1.64

69.8

0.04

 Small

149/100

207/213

1.78

0.37–8.60

94.6

<0.01

Ethnicity

 Caucasian

255/241

635/898

1.04

0.70–1.53

62.0

0.05

 Mixed

184/178

204/285

2.73

0.28–27.09

97.3

<0.01

Tumour site

 Lung

149/156

466/804

1.28

0.77–2.13

68.4

0.08