Twenty studies were included in the review (12 prospective, 5 retrospective and 3 combined) with 6,865 participants. Six of the reports included a control group.
The percentage of relatives found to have neoplasms (adenomas or carcinomas) ranged from 1.4 to 63%, for adenomas from 1.4 to 59%, and for carcinomas, 0 to 7.5%.
Using FOBT (3,206 participants), the percentage of neoplasms was 1.7%, the percentage of adenoma was 1.0%, and the percentage of carcinoma was 0.7%.
Using FS (1,199 participants), the percentage of neoplasms was 12.3%, the percentage of adenoma was 10.4%, and the percentage of carcinoma was 0.08%.
Using colonoscopy (2,562 participants), the percentage of neoplasms was 25.4%, the percentage of adenoma was 21.3%, and the percentage of carcinoma was 3.5%.