Table 1 Basic characteristics of the samples in the two-stage case-control study
| Â | Discovery stage | Replication stage | Combined | |||
|---|---|---|---|---|---|---|
Cases (n, %) | Controls (n, %) | Cases (n, %) | Controls (n, %) | Cases (n, %) | Controls (n, %) | |
Gender | ||||||
 Female | 432 (45.4) | 418 (47.8) | 232 (44.9) | 224 (40.7) | 664 (45.2) | 642 (45.1) |
 Male | 520 (54.6) | 457 (52.2) | 285 (55.1) | 326 (59.3) | 805 (54.8) | 783 (54.9) |
Age | ||||||
 Mean ± SD (years) | 62.8 ± 12.3 | 55.3 ± 11.8 | 55.1 ± 10.7 | 45.2 ± 11.7 | 60.1 ± 12.3 | 51.4 ± 12.7 |
Tumor location | ||||||
 Colon | 453 (47.9) |  | 232 (44.9) |  | 685 (46.6) |  |
 Rectum | 471 (49.5) |  | 223 (43.1) |  | 694 (47.2) |  |
 Missing | 28 (2.6) |  | 62 (12.0) |  | 90 (6.1) |  |