Table 4.
Odds ratios (ORs) for breast cancer and smoking in relation to the CYP1A1 genotype at the M1 locus, according to menopausal status (White and African-American women combined)
| All participants | Premenopausal | Postmenopausal | ||||||||||
| M1 genotypea | wt genotypeb | M1 genotype | wt genotype | M1 genotype | wt genotype | |||||||
| Cases/controls | OR (95% CI)c | Cases/controls | OR (95% CI)c | Cases/controls | OR (95% CI)c | Cases/controls | OR (95% CI)c | Cases/controls | OR (95% CI)c | Cases/controls | OR (95% CI)c | |
| Active smoking status | ||||||||||||
| Never | 96/115 | Reference | 252/256 | Reference | 46/47 | Reference | 132/120 | Reference | 50/68 | Reference | 120/136 | Reference |
| Former | 65/47 | 1.7 (1.1–2.8) | 143/129 | 1.2 (0.9–1.6) | 37/26 | 1.5 (0.8–2.9) | 62/53 | 1.0 (0.7–1.6) | 28/21 | 1.9 (1.0–3.8) | 81/76 | 1.3 (0.9–1.9) |
| Current | 35/43 | 1.1 (0.6–1.8) | 87/105 | 0.8 (0.6–1.2) | 20/25 | 0.8 (0.4–1.7) | 48/48 | 0.9 (0.6–1.4) | 15/18 | 1.2 (0.6–2.7) | 39/57 | 0.8 (0.5–1.3) |
| Number of cigarettes smoked (pack/day) | ||||||||||||
| Never | 96/115 | Reference | 252/256 | Reference | 46/47 | Reference | 132/120 | Reference | 50/58 | Reference | 120/136 | Reference |
| ≤ 1 | 71/64 | 1.4 (0.9–2.2) | 159/159 | 1.0 (0.8–1.4) | 43/38 | 1.2 (0.6–2.2) | 76/70 | 1.0 (0.6–1.5) | 28/26 | 1.6 (0.8–3.0) | 83/89 | 1.1 (0.7–1.6) |
| >1 | 29/26 | 1.4 (0.8–2.7) | 68/74 | 1.0 (0.7–1.4) | 14/13 | 1.1 (0.5–2.7) | 32/30 | 0.9 (0.5–1.7) | 15/13 | 1.7 (0.7–4.0) | 36/44 | 1.0 (0.6–1.6) |
| Duration of smoking | ||||||||||||
| Never | 96/115 | Reference | 252/256 | Reference | 46/47 | Reference | 132/120 | Reference | 50/58 | Reference | 120/136 | Reference |
| ≤ 20 years | 51/57 | 1.0 (0.6–1.7) | 119/127 | 0.9 (0.7–1.3) | 37/39 | 1.0 (0.5–1.8) | 80/77 | 0.9 (0.6–1.4) | 14/18 | 1.1 (0.5–2.4) | 39/50 | 0.9 (0.6–1.5) |
| > 20 years | 49/33 | 2.1 (1.2–3.5) | 110/106 | 1.2 (0.9–1.6) | 20/12 | 1.9 (0.8–4.4) | 30/23 | 1.2 (0.7–2.2) | 29/21 | 2.1 (1.0–4.1) | 80/83 | 1.2 (0.8–1.7) |
| Former smokers: time since cessation of smoking | ||||||||||||
| Never | 96/115 | Reference | 252/256 | Reference | 46/47 | Reference | 132/120 | Reference | 50/58 | Reference | 120/136 | Reference |
| < 10 years | 41/14 | 3.7 (1.9–7.3) | 76/53 | 1.5 (1.0–2.2) | 23/8 | 2.9 (1.2–7.3) | 33/24 | 1.1 (0.6–2.1) | 18/6 | 4.6 (1.7–12.5) | 43/29 | 1.8 (1.0–3.0) |
| ≥ 10 years | 24/33 | 1.0 (0.5–1.7) | 67/76 | 1.0 (0.7–1.4) | 14/18 | 0.8 (0.4–2.0) | 29/29 | 0.9 (0.5–1.7) | 10/15 | 0.9 (0.4–2.3) | 38/47 | 1.0 (0.6–1.6) |
| Age started of smoking | ||||||||||||
| Never | 96/115 | Reference | 252/256 | Reference | 46/47 | Reference | 132/120 | Reference | 50/58 | Reference | 120/136 | Reference |
| <18 years | 35/25 | 1.7 (0.9–3.0) | 87/84 | 1.0 (0.7–1.5) | 24/12 | 1.9 (0.8–4.3) | 45/44 | 0.9 (0.5–1.4) | 11/13 | 1.2 (0.5–3.0) | 42/40 | 1.2 (0.8–2.1) |
| ≥ 18 years | 65/65 | 1.3 (0.9–2.1) | 143/150 | 1.0 (0.8–1.4) | 33/39 | 0.9 (0.5–1.7) | 65/57 | 1.1 (0.7–1.7) | 32/26 | 1.8 (0.9–3.4) | 78/93 | 1.0 (0.7–1.5) |
| Exposure to ETS | ||||||||||||
| Unexposed to active smoking or ETS after age 18 | 36/48 | Reference | 95/84 | Reference | 20/29 | Reference | 56/51 | Reference | 16/19 | Reference | 39/33 | Reference |
| ETS after age 18 | 60/67 | 1.4 (0.8–2.5) | 156/172 | 0.9 (0.7–1.4) | 26/18 | 2.5 (1.0–6.1) | 76/69 | 1.2 (0.7–2.0) | 34/49 | 0.7 (0.3–1.7) | 80/103 | 0.7 (0.4–1.2) |
CI, confidence interval; wt, wild type; ETS, environmental tobacco smoke. a M1/M1 and M1/wt genotypes. b wt/wt genotype. cAdjusted for age, race, and sampling fractions.