High test positivity and low positive predictive value for colorectal cancer of continued faecal occult blood test screening after negative colonoscopy. (June 2018)

• Record Type: Journal Article
• Authors: Brown, Jeremy P; Wooldrage, Kate; Wright, Suzanne; Nickerson, Claire; Cross, Amanda J; Atkin, Wendy S
• Is Part Of: Journal of medical screening. Volume 25:Number 2(2018)
• Page Start: 70
• Page End: 75
• Publication Date: 2018-06
• Subjects: Colorectal cancer -- gFOBT -- colonoscopy -- screening programme -- faecal occult blood test; Medical screening -- Periodicals; 362.177
• DOI: 10.1177/0969141317698501
• Languages: English
• ISSNs: 0969-1413

Abstract

Objectives: The English Bowel Cancer Screening Programme offers biennial guaiac faecal occult blood test (gFOBT) screening to 60–74-year-olds. Participants with positive results are referred for follow-up, but many do not have significant findings. If they remain age eligible, these individuals are reinvited for gFOBT screening. We evaluated the performance of repeat screening in this group. Methods: We analysed data on programme participants reinvited to gFOBT screening after either previous negative gFOBT ( n = 327, 542), or positive gFOBT followed by a diagnostic investigation negative for colorectal cancer (CRC) or adenomas requiring surveillance ( n = 42, 280). Outcomes calculated were uptake, test positivity, yield of CRC, and positive predictive value (PPV) of gFOBT for CRC. Results: For participants with a previous negative gFOBT, uptake in the subsequent screening round was 87.5%, positivity was 1.3%, yield of CRC was 0.112% of those adequately screened, and the PPV of gFOBT for CRC was 9.1%. After a positive gFOBT and a negative diagnostic investigation, uptake in the repeat screening round was 82.6%, positivity was 11.3%, CRC yield was 0.172% of participants adequately screened, and the PPV of gFOBT for CRC was 1.7%. Conclusion: With high positivity and low PPV for CRC, the suitability of routine repeat gFOBT screening in two years among individuals with a previous positive test and a negative diagnostic examination needs to be carefully considered.