| Characteristics | Category | Sub-category | N = 41 pairs |
| Gender | Men |
| 17 (42%) |
|
| Women |
| 21 (51%) |
|
| Unknown |
| 3 (7%) |
| Ethnicity | African-American |
| 11 (27%) |
|
| Caucasian |
| 27 (66%) |
|
| Unknown |
| 3 (7%) |
| Age (years) | ≥55 | African American | 9 (28%) |
|
|
| Caucasian | 23 (72%) |
|
|
| Total | 32 |
|
| ≤55 | African American | 2 (33%) |
|
|
| Caucasian | 4 (67%) |
|
|
| Total | 6 |
|
| Unknown | Total | 3 |
| Differentiation | Tubular |
| 7 (12%) |
|
| Tubulovillous |
| 14 (25%) |
|
| Villous |
| 10 (17%) |
|
| Polypvillous |
| 8 (14%) |
|
| Cancer |
| 18 (32%) |