Table 1.
Characteristics of study participants. Values are numbers (percentages) unless stated otherwise
| Characteristics | Cases (n=68 060) | Controls (n=333 753) |
|---|---|---|
| Women | 31 464 (46.2) | 154 526 (46.3) |
| Mean (SD) age (years) | 63.4 (10.5) | 63.3 (10.5) |
| Age groups (years): | ||
| <50 | 7372 (10.8) | 36 668 (11.0) |
| 50-59 | 15 143 (22.3) | 75 151 (22.5) |
| 60-69 | 25 937 (38.1) | 127 781 (38.3) |
| ≥70 | 19 608 (28.8) | 94 153 (28.2) |
| Mean (SD) year of birth | 1943.3 (9.2) | 1943.4 (9.2) |
| Mean (SD) No of FDRs | 4.2 (2.6) | 4.6 (3.0) |
| No of FDRs with polyps: | ||
| 0 | 62 318 (91.6) | 314 893 (94.4) |
| 1 | 5220 (7.7) | 17 627 (5.3) |
| ≥2 | 522 (0.8) | 1233 (0.4) |
| No of FDRs with CRC: | ||
| 0 | 60 472 (88.9) | 311 400 (93.3) |
| 1 | 7059 (10.4) | 21 446 (6.4) |
| ≥2 | 529 (0.8) | 907 (0.3) |
| Mean (SD) youngest age at polyp diagnosis in FDRs (years)* | 66.7 (11.6) | 67.5 (11.3) |
| Youngest age at polyp diagnosis in FDRs (years): | ||
| <50 | 438 (0.1) | 1170 (0.1) |
| 50-59 | 1085 (0.2) | 3464 (0.2) |
| 60-69 | 1753 (0.3) | 5724 (0.3) |
| ≥70 | 2466 (0.4) | 8502 (0.5) |
| Types of lesions in at least one FDR: | ||
| Hyperplastic polyps | 1667 (2.5) | 6114 (1.8) |
| Sessile serrated polyps | 123 (0.2) | 437 (0.1) |
| Tubular adenomas | 2458 (3.6) | 7783 (2.3) |
| Tubulovillous adenomas | 1856 (2.7) | 5437 (1.6) |
| Villous adenomas | 252 (0.4) | 697 (0.2) |
| Advanced polyps | 2194 (3.2) | 6477 (1.9) |
| Mean (SD) total No of past clinic visits | 10.4 (12.1) | 7.4 (10.2) |
| Mean (SD) Charlson comorbidity index score | 0.5 (0.9) | 0.4 (0.8) |
| Comorbidities: | ||
| Myocardial infarction | 3178 (4.7) | 13 694 (4.1) |
| Congestive heart failure | 1926 (2.8) | 6660 (2.0) |
| Peripheral vascular disease | 1462 (2.2) | 5371 (1.6) |
| Cerebrovascular disease | 3952 (5.8) | 16 936 (5.1) |
| Dementia | 347 (0.5) | 2283 (0.7) |
| Chronic pulmonary disease | 4127 (6.1) | 15 750 (4.7) |
| Connective tissue disease-rheumatic disease | 1339 (2.0) | 5842 (1.8) |
| Peptic ulcer disease | 1872 (2.8) | 3121 (0.9) |
| Mild liver disease | 808 (1.2) | 1798 (0.5) |
| Diabetes without complications | 4663 (6.9) | 14 414 (4.3) |
| Diabetes with complications | 1654 (2.4) | 5367 (1.6) |
| Paraplegia and hemiplegia | 328 (0.5) | 1262 (0.4) |
| Renal disease | 629 (0.9) | 2027 (0.6) |
| Cancer, excluding CRC | 7422 (10.9) | 25 802 (7.7) |
| Moderate or severe liver disease | 213 (0.3) | 534 (0.2) |
| Metastatic carcinoma of unspecified sites | 1864 (2.7) | 2098 (0.6) |
| AIDS/HIV | 36 (0.1) | 138 (0.0) |
CRC=colorectal cancer; FDR=first degree relative (parents and full siblings).
All variables were assessed at time of CRC diagnosis for cases and their matched controls.
*
Among FDRs with a history of polyps.