Bowel cancer screening — KFP-style written assessment

KFP 1 (10 marks)

A 64-year-old man's National Bowel Cancer Screening Program kit returns positive. His wife phones, alarmed. When he attends, he says he feels completely well and asks whether "the test might have got it wrong". He has no bowel symptoms, no family history, takes ibuprofen occasionally for knees. ^[15]

1. What does the positive result mean numerically, and what single action follows? (3) ^[15]
2. How do you answer "might it have got it wrong"? (4) ^[15]
3. He asks what happens if the colonoscopy finds nothing. (3) ^[10]

Model answers

1. A positive immunochemical FOBT means blood in the stool that he cannot see, detected at the programme threshold. The numbers: in 2024, 73,745 Australians returned positive kits (5.8% positivity), and among those with a recorded diagnostic assessment, 1 in 29 had confirmed or suspected cancer and 1 in 3 had an adenoma. One action follows — colonoscopy, arranged through the appropriate referral pathway without delay; median programme time from positive result to assessment is 62 days and his practice should beat that. ^[15]
2. Yes, false positives occur — that is inherent to any screening test chosen to catch many cancers. But the response to uncertainty is not repetition: repeating the kit delays diagnosis of exactly the lesions being hunted, and a negative repeat would not exclude them. The trade has been made deliberately: accept roughly one colonoscopy per three adenomas and one per 29 cancers found. Ibuprofen can cause occult bleeding — mention it to the endoscopist, but it neither cancels nor downgrades the investigation. ^[15]
3. Then the positive has been explained or outgrown, and he returns to two-yearly population screening — a normal colonoscopy after a positive FIT carries no special surveillance. The episode closes with a documented plan and a date for the next kit, not with discharge into silence. ^[10]