1. Interval cancers in a national colorectal screening programme based on faecal immunochemical testing: Implications for faecal haemoglobin concentration threshold and sex inequality.
- Author
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Clark, Gavin RC, Godfrey, Thomas, Purdie, Calum, Strachan, Judith, Carey, Francis A, Fraser, Callum G, and Steele, Robert JC
- Subjects
FECAL analysis ,CLINICAL pathology ,IMMUNOCHEMISTRY ,HEMOGLOBINS ,COLONOSCOPY ,AGE distribution ,EARLY detection of cancer ,COLORECTAL cancer ,SEX distribution ,COMPARATIVE studies ,DESCRIPTIVE statistics ,GUAIAC ,FECAL occult blood tests ,SENSITIVITY & specificity (Statistics) ,DIAGNOSTIC errors ,LONGITUDINAL method ,EVALUATION - Abstract
Objective: To compare interval cancer proportions (ICP) in the faecal immunochemical test (FIT)-based Scottish Bowel Screening Programme (SBoSP) with the former guaiac faecal occult blood test (gFOBT)-based SBoSP and investigate associations between interval cancer (IC) and faecal haemoglobin concentration (f-Hb) threshold, sex, age, deprivation, site, and stage. Methods: The ICP data from first year of the FIT-based SBoSP and the penultimate year of the gFOBT-based SBoSP were compared in a prospective cohort design. Results: With FIT, 801 colorectal cancers (CRCs) were screen detected (SDC), 802 were in non-participants, 548 were ICs, 39 were colonoscopy missed and 72 were diagnosed after incomplete screening; with gFOBT: 540, 904, 556, 45, and 13, respectively. FIT had a significantly higher proportion of SDC compared to IC than gFOBT. For FIT and gFOBT, ICP was significantly higher in women than men. As f-Hb threshold increased, ICP increased and, for any f-Hb threshold for men, a lower threshold was required for comparable ICP in women. In Scotland, the current threshold of ≥80 µg Hb/g faeces would have to be lowered to ≥40 µg Hb/g faeces for women to achieve sex equality for ICP. In the FIT-based SBoSP, there were four times as many stage I SDC than IC. This was reversed in advanced stages, with twice as many stage IV CRC diagnosed as IC versus SDC. Conclusions: Reducing the numbers of IC requires lowering the f-Hb threshold. Using different f-Hb thresholds for women and men could eliminate the sex disparity, but with additional colonoscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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