Table 3.
Smoker distribution in tested population.
| Smoking Status | Population N (%) | χ2 | p | |
|---|---|---|---|---|
| Cancer Groups | Control Groups | |||
| A. Lung Cancer | 200 (100.00) | 352 (100.00) | ||
| Non-smoking | 118 (59.00) | 256 (72.73) | ||
| Smoking | 82 (41.00) | 96 (27.27) | 11.00 | <0.01 * |
| Mild | 16 (8.00) | 69 (19.60) | ||
| Heavy | 66 (33.00) | 27 (7.67) | 48.00 | <0.01 * |
| B. Colorectal Cancer | 335 (100.00) | 352 (100.00) | ||
| Non-smoking | 262 (78.21) | 256 (72.73) | ||
| Smoking | 73 (21.79) | 96 (27.27) | 2.78 | 0.10 |
| Mild | 25 (7.46) | 52 (14.77) | ||
| Heavy | 48 (14.33) | 44 (12.50) | 6.63 | 0.01 * |
| C. Colon Cancer | 130 (100.00) | 352 (100.00) | ||
| Non-smoking | 100 (76.92) | 256 (72.73) | ||
| Smoking | 30 (23.08) | 96 (27.27) | 0.87 | 0.35 |
| Mild | 10 (7.69) | 52 (14.77) | ||
| Heavy | 20 (15.38) | 44 (12.50) | 3.97 | 0.04 * |
| D. Rectum Cancer | 205 (100.00) | 352 (100.00) | ||
| Non-smoking | 162 (79.02) | 256 (72.73) | ||
| Smoking | 43 (20.98) | 96 (27.27) | 2.74 | 0.10 |
| Mild | 15 (7.32) | 52 (14.77) | ||
| Heavy | 28 (13.66) | 44 (12.50) | 4.42 | 0.04 * |
Smoker distribution analysis performed by the χ2 test. Mild smoker, a person who used cigarettes <average ASV, i.e., 30 pack-years in the lung cancer group and 20 pack-years in the colorectal cancer groups; heavy smoker, a person who used cigarettes ≥average ASV. * indicates significance statistically. Those p values lower than 0.01 such as 0.008, 0.005, 0.003, etc. all were expressed as <0.01, other p values equal or larger than 0.01 are shown by the exact numbers in this or following Tables.