Alternative Treatments Cancer prevention tests should be offered to all patients meeting criteria for CRC screening. The preferred cancer prevention test is colonoscopy. Alternative cancer prevention tests include flexible sigmoidoscopy and computed tomography colonography. Patients who decline colonoscopy or a cancer prevention test should be offered a cancer detection test. The preferred cancer detection test is fecal immunochemical testing. Alternative cancer detection tests included Hemoccult Sensa fecal guaiac based testing and fecal DNA testing. No CRC screening is an alternative.(1)