Table IV.
Risk of all polyps combined in association with cigarette smoking by carcinogen-metabolizing risk category, the TCPS, 2003–2010
| Smoking | Carcinogen-metabolizing risk score | |||||
|---|---|---|---|---|---|---|
| Low risk | Intermediate risk | High risk | ||||
| n a | OR (95% CI)b | n a | OR (95% CI)b | n a | OR (95% CI)b | |
| Smoking status | ||||||
| Never | 261/656 | 1.0 (reference) | 344/916 | 0.9 (0.8–1.1) | 67/182 | 0.9 (0.7–1.3) |
| Former | 286/405 | 1.4 (1.1–1.7) | 406/630 | 1.3 (1.1–1.6) | 88/117 | 1.6 (1.2–2.2) |
| Current | 207/156 | 2.9 (2.2–3.8) | 328/227 | 3.0 (2.4–3.9) | 69/43 | 3.4 (2.2–5.2) |
| Test of interaction, P = 0.341 | ||||||
| Pack-years | ||||||
| Never | 261/656 | 1.0 (reference) | 344/916 | 0.9 (0.8–1.1) | 67/182 | 0.9 (0.7–1.3) |
| 1–9 | 101/156 | 1.6 (1.2–2.1) | 137/277 | 1.2 (0.9–1.6) | 36/54 | 1.6 (1.0–2.5) |
| 10–29 | 149/178 | 1.8 (1.4–2.4) | 213/268 | 1.7 (1.3–2.1) | 34/65 | 1.2 (0.7–1.8) |
| ≥30 | 242/227 | 2.0 (1.5–2.5) | 380/307 | 2.3 (1.8–2.9) | 84/40 | 4.0 (2.6–6.1) |
| Test of interaction, P = 0.032 | ||||||
| Cigarettes per day | ||||||
| Never | 261/656 | 1.0 (reference) | 344/916 | 0.9 (0.8–1.1) | 67/182 | 1.0 (0.7–1.3) |
| 1–19 | 183/211 | 2.1 (1.6–2.7) | 269/345 | 1.8 (1.4–2.2) | 44/75 | 1.4 (0.9–2.1) |
| 20–29 | 151/187 | 1.5 (1.1–1.9) | 233/292 | 1.5 (1.2–1.9) | 64/54 | 2.3 (1.6–3.5) |
| ≥30 | 159/163 | 1.7 (1.3–2.2) | 230/215 | 1.8 (1.4–2.3) | 49/30 | 2.9 (1.8–4.8) |
| Test of interaction, P = 0.025 | ||||||
| Years of cigarette smoking | ||||||
| Never | 261/656 | 1.0 (reference) | 344/916 | 0.9 (0.8–1.1) | 67/182 | 1.0 (0.7–1.3) |
| 1–14 | 86/159 | 1.2 (0.9–1.6) | 110/284 | 0.9 (0.7–1.2) | 35/54 | 1.6 (1.0–2.6) |
| 15–24 | 83/122 | 1.4 (1.0–2.0) | 104/158 | 1.3 (1.0–1.8) | 21/32 | 1.5 (0.8–2.6) |
| 25–34 | 111/121 | 2.0 (1.5–2.7) | 181/185 | 2.1 (1.6–2.8) | 35/35 | 2.1 (1.3–3.6) |
| ≥35 | 212/159 | 2.4 (1.8–3.3) | 337/229 | 2.9 (2.3–3.7) | 63/39 | 3.2 (2.2–4.7) |
| Test of interaction, P = 0.294 | ||||||
an, number of cases/controls. The total number of subjects was 5380 (including 2054 cases and 3326 controls). Sixteen subjects were deleted because of missing data.
bAdjusted for age, sex, study sites, educational attainment, alcohol consumption, BMI, physical activity, regular NSAID use, red meat intake, total energy intake, year of recruitment and recruitment before or after colonoscopy.