Table 2.
Crude and adjusted odds ratios (OR) and adjusted 95% confidence intervals for departure from multiplicative interaction between COMT genotype and risk of active exposure to tobacco
| COMT Genotype | COMT-HL vs. COMT-LL | COMT-HH vs. COMT-LL | |||
| Measures of dose, duration and timing | COMT-LL | COMT-HL | COMT-HH | aOR*§ (95% CI) | aOR*§ (95% CI) |
| Never active/never passive ‡ | 12 | 32 | 24 | 1.0 (--) | 1.0 (--) |
| Active smoker | 39 | 123 | 85 | 1.6 (0.7–3.8) | 1.2 (0.4–3.1) |
| Packs (per day) | |||||
| < 1 packs | 24 | 75 | 44 | 1.5 (0.6–3.9) | 1.1 (0.4–3.1) |
| ≥ 1 packs | 15 | 45 | 40 | 1.6 (0.6–4.5) | 1.2 (0.4–3.7) |
| Missing | 0 | 3 | 1 | † | † |
| Duration (years) | |||||
| < 40 | 29 | 83 | 60 | 1.3 (0.5–3.4) | 1.1 (0.4–3.0) |
| 40+ | 9 | 40 | 24 | 2.3 (0.8–7.0) | 1.4 (0.4–4.9) |
| Missing | 1 | 0 | 1 | † | † |
| Age started (years) | |||||
| < 22 | 30 | 95 | 66 | 1.6 (0.7–4.1) | 1.1 (0.4–3.0) |
| ≥ 22 | 8 | 28 | 18 | 1.5 (0.5–4.6) | 1.5 (0.4–5.4) |
| Missing | 1 | 0 | 1 | † | † |
| Quit smoking before diagnosis date (years) | |||||
| Current/<5 | 11 | 17 | 16 | 0.8 (0.2–2.5) | 0.7 (0.2–2.5) |
| 5 – 15 | 9 | 29 | 18 | 1.6 (0.5–5.0) | 0.8 (0.2–2.9) |
| > 15 | 17 | 57 | 39 | 1.5 (0.6–4.2) | 1.1 (0.4–3.3) |
| Missing | 2 | 20 | 12 | † | † |
* Adjusted odds ratio
§ Controlling for age, alcohol use, age at first birth, BMI, family history of breast cancer, history of benign breast disease, and geographic site of breast cancer diagnosis
‡ Reference group for all comparisons
† Estimates not provided for category of missing values