Table 2 Summary ORs for various contrasts of CYP1A1 MspI and exon7 gene polymorphisms in this meta-analysis

Total

Type C vs Type A

(TypeB+TypeC) vs Type A

49

1.26(1.12-1.42) 0.003

1.20(1.13-1.28) 0.000

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

40

1.24(1.09-1.42) 0.004

1.15(1.07-1.24) 0.000

Ethnicity

Asian

Type C vs Type A

(TypeB+TypeC) vs Type A

26

1.24(1.12-1.43) 0.004

1.30(1.17-1.44) 0.002

Val/Val vs Ile/Ile

(Ile/Val +Val/Val)vs Ile/Ile

22

1.22(1.16-1.59) 0.016

1.21(1.09-1.34) 0.000

Caucasian

Type C vs Type A

(TypeB+TypeC) vs Type A

11

1.25(1.09-1.36) 0.053

1.35(1.18-1.54) 0.046

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

10

1.24(1.17-1.43) 0.090

1.28(1.12-1.45) 0.000

Mixed population

Type C vs Type A

(TypeB+TypeC) vs Type A

12

1.05(0.89-1.28) 0.140

1.02(0.92-1.14) 0.330

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

8

0.84(0.77-1.03) 0.090

0.92(0.79-1.06) 0.001

Histological type

SCC

Type C vs Type A

(TypeB+TypeC) vs Type A

13

1.87(1.58-2.14)0.005

1.93(1.62-2.30) 0.000

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

11

1.38(1.12-1.66) 0.004

1.42(1.18-1.70) 0.007

AC

Type C vs Type A

(TypeB+TypeC) vs Type A

12

1.34(1.14-1.56)0.014

1.20(1.01-1.43) 0.000

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

10

0.90(0.72-1.08) 0.005

0.95(0.79-1.15) 0.001

SCLC

Type C vs Type A

(TypeB+TypeC) vs Type A

8

0.96(0.70-1.26)0.864

1.06(0.77-1.45) 0.976

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

7

0.84(0.68-1.08)0.068

0.78(0.53-1.14) 0.039

Gender

Male

Type C vs Type A

(TypeB+TypeC) vs Type A

3

1.39(1.23-1.79) 0.210

1.46(1.07-1.98) 0.380

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

7

1.18(0.92-1.35) 0.360

1.15(0.96-1.39) 0.298

Female

Type C vs Type A

(TypeB+TypeC) vs Type A

7

0.92(0.84-1.16) 0.003

0.85(0.71-1.02) 0.000

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

3

1.29(1.08-1.51) 0.000

1.24(1.05-1.47) 0.002

Smoking status

13

10

Smokers

Type C vs Type A

(TypeB+TypeC) vs Type A

1.62(1.33-1.96) 0.000

1.75(1.44-2.13) 0.003

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

1.84(1.36-2.08) 0.003

1.62(1.24-2.11) 0.004

Non-smokers

Type C vs Type A

(TypeB+TypeC) vs Type A

1.18(0.96-1.48) 0.086

1.09(0.90-1.33) 0.114

Val/Val vs Ile/Ile

(Ile/Val +Val/Val) vs Ile/Ile

1.18(0.96-1.38) 0.080

1.07(0.88-1.31) 0.002