Table 1.
Baseline characteristics of cases and controls.
| Characteristics | Casesa | Controls | P valueb |
|---|---|---|---|
| n | 9,592 | 7,869 | |
| Age, mean (SD)c | 58.6 (11.5) | 60.9 (10.3) | <2.2e-16 |
| Sex (%) | |||
| Men | 4,883 (50.9) | 3,713 (47.2) | |
| Women | 4,709 (49.1) | 4,156 (52.8) | 9.9e-07 |
| Tobacco smoking (%)d | |||
| Never smoker | 3,790 (41.8) | 3,292 (46.9) | |
| Past or current smoker | 5,273 (58.2) | 3,731 (53.1) | 1.6e-10 |
| Dietary intake | |||
| Red meat, servings/day, mean (SD)e | 0.77 (0.68) | 0.73 (0.65) | 5.0e-06 |
| processed meat, servings/day, mean (SD)f | 0.29 (0.34) | 0.25 (0.29) | 1.8e-08 |
| Total energy, kcal/day, mean (SD)g | 2118.3 (851.1) | 2024.2 (768.0) | 5.4e-07 |
| Fruits, servings/day, mean (SD)h | 1.82 (1.63) | 2.09 (1.75) | <2.2e-16 |
| Vegetables, servings/day, mean (SD)i | 2.51 (1.98) | 2.95 (2.15) | <2.2e-16 |
| Fiber, g/day, mean (SD)j | 22.9 (10.7) | 23.1 (10.4) | 0.30 |
| Location of colorectal cancer (%) | |||
| Proximal | 3.670 (38.3) | - | |
| Distal | 2,975 (31.0) | - | |
| Rectum | 2,526 (26.4) | - | |
| Missing | 421 (4.4) | - | - |
| Colorectal cancer stage (%) | |||
| I | 2,038 (21.2) | - | |
| II | 1,780 (18.6) | - | |
| III | 1,847 (19.3) | - | |
| IV | 817 (8.5) | - | |
| Missing | 3,110 (32.4) | - | - |
| Microsatellite instability (%) | |||
| High | 1,417 (15.6) | - | |
| Stable/low | 7,639 (84.4) | - | - |
| CpG island methylator phenotype (%) | |||
| High | 1,298 (18.9) | - | |
| Low | 5,569 (81.1) | - | - |
| BRAF (%) | |||
| Mutated | 1,109 (12.8) | - | |
| Wildtype | 7,566 (87.2) | - | - |
| KRAS (%) | |||
| Mutated | 2,355 (32.8) | - | |
| Wildtype | 4,831 (67.2) | - | - |
a
The number of cases includes 809 colorectal cancer cases from the Mayo Clinic CCFR, which is not included controls.
b
Based on Chi-square test or Mann-Whitney t test.
c
Age is missing for 4 cases and 4 controls.
d
Tobacco smoking is missing for 529 cases and 846 controls.
e
Red meat intake is missing for 743 cases and 966 controls.
f
Processed meat intake is missing for 4,606 cases and 1,959 controls.
g
Total energy intake is missing for 4,067 cases and 1,406 controls.
h
Fruit intake is missing for 850 cases and 1,083 controls.
i
Vegetables intake is missing for 731 cases and 1,044 controls.
j
Fiber intake is missing for 4,038 cases and 1,384 controls.
Abbreviations: SD: standard deviation.