In bowel cancer screening using a faecal immunochemical test (FIT), what is the recommended interval?

• A. Every 6 months
• B. Every 1 year
• C. Every 2 years
• D. Every 5 years

Answer: (C)

FIT screens for hidden blood in stool to detect potential colorectal neoplasia. Because it is not diagnostic, the screening schedule must balance how often bleeding from a lesion might occur with the resources required to follow up positive results. Cancers and advanced adenomas often bleed intermittently, and progression from adenoma to cancer takes years, so testing every two years provides a good chance of catching a lesion during a bleed while avoiding excessive testing and follow-up. If you screened every 6 months or annually, you’d increase costs and possible false alarms without substantial gain in detection; screening every 5 years could miss cancers developing between tests. So the recommended interval is every two years.