Colonoscopic screening of individuals with two first degree relatives with colorectal cancer or a relative affected under the age of 50 years (1:6–1:10 risk)
| Age (y) | No screened (%) | No with adenoma (%) | No with adenoma >1cm or severe dysplasia (%) |
| <20 | 4 (5) | 1 (25) | 1 (25) |
| 20–29 | 12 (14) | 1 (8) | 0 |
| 30–39 | 15 (18) | 0 | 0 |
| 40–49 | 20 (24) | 0 | 0 |
| 50–59 | 15 (18) | 2 (13) | 2 (13) |
| 60–69 | 17 (20) | 5 (29) | 4 (24) |
| Total | 83 (100) | 9 (11) | 7 (8) |