Table 8

Odds ratios (ORs) for breast cancer according to cigarette smoking and the CYP1A1 genotype at the M1 locus, according to menopausal status (African-American and white women combined), additive scale and interaction contrast ratios

Genotype

Overall

Premenopausal

Postmenopausal

Cases/controls

OR (95% CI)^a

ICR (95% CI)

Cases/controls

OR (95% CI)^a

ICR (95% CI)

Cases/controls

OR (95% CI)^a

ICR (95% CI)

Active smoking status

Never

wt/wt^b

252/256

Reference

132/120

Reference

120/136

Reference

Never

M1 variant^c

96/115

0.8 (0.6–1.2)

46/47

0.9 (0.5–1.4)

50/68

0.8 (0.5–1.3)

Former

wt/wt

143/129

1.2 (0.9–1.6)

62/53

1.0 (0.7–1.6)

81/76

1.3 (0.9–1.9)

Former

M1 variant

65/47

1.4 (0.9–2.2)

+0.4 (-0.2, 1.1)

37/26

1.3 (0.7–2.2)

+0.4 (-0.5, 1.2)

28/21

1.5 (0.8–2.9)

+0.5 (-0.5, 1.5)

Current

wt/wt

87/105

0.8 (0.6–1.2)

48/48

0.9 (0.5–1.4)

39/57

0.8 (0.5–1.3)

Current

M1 variant

35/43

0.9 (0.5–1.4)

20/25

0.7 (0.4–1.4)

15/18

1.0 (0.5–2.1)

Number of cigarettes (pack/day)

Never

wt/wt^b

252/256

Reference

132/120

Reference

120/136

Reference

Never

M1 variant^c

96/115

0.8 (0.6–1.2)

46/47

0.9 (0.5–1.4)

50/68

0.8 (0.5–1.3)

≤ 1

wt/wt

159/159

1.0 (0.8–1.4)

76/70

1.0 (0.6–1.4)

83/89

1.1 (0.7–1.6)

≤ 1

M1 variant

71/64

1.2 (0.8–1.7)

43/38

1.0 (0.6–1.7)

28/26

1.3 (0.7–2.3)

> 1

wt/wt

68/74

1.0 (0.7–1.4)

32/30

0.9 (0.5–1.6)

36/44

1.0 (0.6–1.7)

> 1

M1 variant

29/26

1.2 (0.7–2.1)

+0.4 (-0.4, 1.1)

14/13

1.0 (0.4–2.2)

+0.1 (-0.9, 1.1)

15/13

1.4 (0.6–3.0)

+0.6 (-0.6, 1.7)

Duration of smoking

Never

wt/wt^b

252/256

Reference

132/120

Reference

120/136

Reference

Never

M1 variant^c

96/115

0.8 (0.6–1.2)

46/47

0.9 (0.5–1.4)

50/68

0.8 (0.5–1.3)

≤ 20 years

wt/wt

119/127

0.9 (0.7–1.2)

80/77

0.9 (0.6–1.3)

39/50

0.9 (0.6–1.5)

≤ 20 years

M1 variant

51/57

0.9 (0.6–1.3)

37/39

0.8 (0.5–1.4)

14/18

0.9 (0.4–1.7)

> 20 years

wt/wt

110/106

1.2 (0.9–1.6)

30/23

1.2 (0.7–2.2)

80/83

1.2 (0.8–1.7)

> 20 years

M1 variant

49/33

1.7 (1.1–2.8)

+0.7 (-0.2, 1.6)

20/12

1.5 (0.7–3.3)

+0.5 (-0.7, 3.8)

29/21

1.7 (0.9–3.1)

+0.7 (-1.4, 5.3)

Time since cessation

Never

wt/wt^b

252/256

Reference

132/120

Reference

120/136

Reference

Never

M1 variant^c

96/115

0.8 (0.6–1.2)

46/47

0.9 (0.5–1.4)

50/68

0.8 (0.5–1.3)

< 10 years

wt/wt

76/53

1.5 (1.0–2.2)

33/24

1.1 (0.6–2.0)

43/29

1.8 (1.0–3.0)

< 10 years

M1 variant

41/14

3.0 (1.6–5.7)

+1.7 (-0.7, 3.8)

23/8

2.4 (1.0–5.7)

+1.6 (-0.7, 3.8)

18/6

3.6 (1.4–9.4)

+2.0 (-1.4, 5.3)

≥ 10 years

wt/wt

67/76

1.0 (0.7–1.5)

29/29

0.9 (0.5–1.7)

38/47

1.0 (0.6–1.6)

≥ 10 years

M1 variant

24/33

0.8 (0.4–1.3)

14/18

0.7(0.3–1.5)

10/15

0.7 (0.3–1.7)

Age started smoking

Never

wt/wt^b

252/256

Reference

132/120

Reference

120/136

Reference

Never

M1 variant^c

96/115

0.8 (0.6–1.2)

46/47

0.9 (0.5–1.4)

50/68

0.8 (0.5–1.3)

< 18 years

wt/wt

87/84

1.0 (0.7–1.5)

45/44

0.8 (0.5–1.4)

42/40

1.3 (0.8–2.1)

< 18 years

M1 variant

35/25

1.4 (0.8–2.4)

+0.5 (-0.3, 1.4)

24/12

1.6 (0.8–3.4)

+0.9 (-0.4, 2.2)

11/13

1.0 (0.4–2.4)

-0.1 (-1.1, 1.0)

≥ 18 years

wt/wt

143/150

1.0 (0.8–14)

65/57

1.0 (0.7–1.6)

78/93

1.0 (0.7–1.5)

≥ 18 years

M1 variant

65/65

1.1 (0.7–1.6)

33/39

0.8 (0.5–1.4)

32/26

1.4 (0.8–2.6)

CI, confidence interval. ^a Adjusted for age, race, and sampling fractions. ^b wt = wild-type homozygote genotype. ^c M1 variant = M1/M1 or M1/wt genotypes.

Li et al. Breast Cancer Res 2004 6:R460   doi:10.1186/bcr814