Table 1 Risk of colorectal cancer according to cigarette smoking
| Â | Number (%) | Â | Â | |
|---|---|---|---|---|
Cigarette-years | Cases | Controls | OR (95% CI)* | OR (95% CI)†|
Both sexes | Â | Â | Â | Â |
   0 | 299 (43.6) | 326 (41.9) | 1.00 (referent) | 1.00 (referent) |
   1-399 | 117 (17.1) | 201 (25.8) | 0.68 (0.50-0.94) | 0.65 (0.47-0.89) |
   400-799 | 195 (28.5) | 180 (23.1) | 1.21 (0.88-1.68) | 1.16 (0.83-1.62) |
   ≥800 | 74 (10.8) | 71 (9.1) | 1.21 (0.79-1.86) | 1.14 (0.73-1.77) |
Men | Â | Â | Â | Â |
   0 | 80 (18.8) | 92 (18.8) | 1.00 (referent) | 1.00 (referent) |
   1-399 | 94 (22.1) | 158 (32.2) | 0.73 (0.49-1.09) | 0.69 (0.46-1.04) |
   400-799 | 182 (42.7) | 171 (34.9) | 1.24 (0.85-1.81) | 1.15 (0.78-1.71) |
   ≥800 | 70 (16.4) | 69 (14.1) | 1.16 (0.72-1.87) | 1.05 (0.64-1.71) |
Women | Â | Â | Â | Â |
   0 | 219 (84.6) | 234 (81.3) | 1.00 (referent) | 1.00 (referent) |
   1-399 | 23 (8.9) | 43 (14.9) | 0.55 (0.32-0.95) | 0.48 (0.27-0.86) |
   ≥400 | 17 (6.6) | 11 (3.8) | 1.59 (0.72-3.51) | 1.54 (0.67-3.55) |