Table 6.
Odds ratios (ORs) for breast cancer and smoking in relation to the CYP1A1 genotype at the M3 locus (African-American women only)
| M3 genotypesa | wt genotypeb | |||
| Cases/controls | OR (95% CI)c | Cases/controls | OR (95% CI)c | |
| Active smoking status | ||||
| Never | 24/32 | Referent | 124/134 | Reference |
| Former | 16/11 | 1.9 (0.7–4.8) | 58/42 | 1.7 (1.1–2.7) |
| Current | 7/10 | 0.9 (0.7–2.8) | 36/51 | 0.8 (0.5–1.3) |
| Number of cigarettes (pack/day) | ||||
| Never | 24/32 | Referent | 124/134 | Reference |
| ≤ 1 | 18/16 | 1.5 (0.6–3.5) | 79/82 | 1.2 (0.8–1.7) |
| > 1 | 5/5 | 1.2 (0.3–4.7) | 14/11 | 1.6 (0.7–3.8) |
| Duration of smoking | ||||
| Never | 24/32 | Referent | 124/134 | Reference |
| ≤ 20 years | 8/13 | 0.8 (0.3–2.2) | 54/55 | 1.2 (0.7–1.8) |
| > 20 years | 15/8 | 2.5 (0.9–7.1) | 39/37 | 1.3 (0.8–2.2) |
| Former smokers: time since cessation of smoking | ||||
| Never | 24/32 | Referent | 124/134 | Reference |
| < 10 years | 13/4 | 4.2 (1.2–14.6) | 32/13 | 3.1 (1.5–6.1) |
| ≥ 10 years | 3/7 | 0.5 (0.1–2.3) | 26/29 | 1.1 (0.6–2.0) |
| Age started smoking | ||||
| Never | 24/32 | Referent | 124/134 | Reference |
| < 18 years | 12/6 | 2.4 (0.8–7.5) | 33/29 | 1.3 (0.7–2.3) |
| ≥ 18 years | 11/15 | 1.0 (0.4–2.5) | 61/64 | 1.2 (0.8–1.8) |
CI, confidence interval; wt, wild type. a M3/M3 and M3/wt genotypes. b wt/wt genotype. cAdjusted for age and sampling fractions.