High test positivity and low positive predictive value for colorectal cancer of continued faecal occult blood test screening after negative colonoscopy
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Objectives
The English Bowel Cancer Screening Programme (BCSP) offers biennial screening with a guaiac faecal occult blood test (gFOBT) to 60-74 year olds. Participants with a positive gFOBT are referred for follow-up, but many do not have significant findings. These individuals are reinvited for gFOBT screening provided they remain in the eligible age range. We evaluated the performance of repeat screening in this group.
Methods
We analysed data on BCSP participants reinvited to gFOBT screening, either after previous negative gFOBT (n=327,542), or after a 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
After a positive gFOBT and a negative diagnostic investigation, gFOBT 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%. For participants with a previous negative gFOBT, in the subsequent screening round uptake 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%.
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 exam needs to be carefully considered.
The English Bowel Cancer Screening Programme (BCSP) offers biennial screening with a guaiac faecal occult blood test (gFOBT) to 60-74 year olds. Participants with a positive gFOBT are referred for follow-up, but many do not have significant findings. These individuals are reinvited for gFOBT screening provided they remain in the eligible age range. We evaluated the performance of repeat screening in this group.
Methods
We analysed data on BCSP participants reinvited to gFOBT screening, either after previous negative gFOBT (n=327,542), or after a 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
After a positive gFOBT and a negative diagnostic investigation, gFOBT 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%. For participants with a previous negative gFOBT, in the subsequent screening round uptake 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%.
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 exam needs to be carefully considered.
Date Issued
2018-06-01
Date Acceptance
2017-02-16
Citation
Journal of Medical Screening, 2018, 25 (2), pp.70-75
ISSN
1475-5793
Publisher
SAGE Publications (UK and US)
Start Page
70
End Page
75
Journal / Book Title
Journal of Medical Screening
Volume
25
Issue
2
Copyright Statement
©The Author(s) 2017 This article is distributed under the terms of the Creative Commons Attribution 3.0 License (http://www.creativecommons.org/licenses/by/3.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
License URL
Sponsor
Cancer Research UK
Grant Number
A16894
Subjects
Colorectal cancer
colonoscopy
faecal occult blood test
gFOBT
screening programme
1117 Public Health And Health Services
Public Health
Publication Status
Published
Date Publish Online
2017-05-03