Repository logo
 

Diagnostic performance of a faecal immunochemical test for patients with low-risk symptoms of colorectal cancer in primary care: an evaluation in the South West of England.

Accepted version
Peer-reviewed

No Thumbnail Available

Type

Article

Change log

Authors

Abel, Gary A 
Atkins, Alex 
Byford, Rachel 
Davies, Sarah-Jane 

Abstract

BACKGROUND: The faecal immunochemical test (FIT) was introduced to triage patients with low-risk symptoms of possible colorectal cancer in English primary care in 2017, underpinned by little primary care evidence. METHODS: All healthcare providers in the South West of England (population 4 million) participated in this evaluation. 3890 patients aged ≥50 years presenting in primary care with low-risk symptoms of colorectal cancer had a FIT from 01/06/2018 to 31/12/2018. A threshold of 10 μg Hb/g faeces defined a positive test. RESULTS: Six hundred and eighteen (15.9%) patients tested positive; 458 (74.1%) had an urgent referral to specialist lower gastrointestinal (GI) services within three months. Forty-three were diagnosed with colorectal cancer within 12 months. 3272 tested negative; 324 (9.9%) had an urgent referral within three months. Eight were diagnosed with colorectal cancer within 12 months. Positive predictive value was 7.0% (95% CI 5.1-9.3%). Negative predictive value was 99.8% (CI 99.5-99.9%). Sensitivity was 84.3% (CI 71.4-93.0%), specificity 85.0% (CI 83.8-86.1%). The area under the ROC curve was 0.92 (CI 0.86-0.96). A threshold of 37 μg Hb/g faeces would identify patients with an individual 3% risk of cancer. CONCLUSIONS: FIT performs exceptionally well to triage patients with low-risk symptoms of colorectal cancer in primary care; a higher threshold may be appropriate in the wake of the COVID-19 crisis.

Description

Keywords

Anemia, Iron-Deficiency, Colorectal Neoplasms, England, Feces, Female, Hemoglobins, Humans, Male, Middle Aged, Occult Blood, Primary Health Care, Risk Factors, Sensitivity and Specificity, Weight Loss

Journal Title

Br J Cancer

Conference Name

Journal ISSN

0007-0920
1532-1827

Volume Title

124

Publisher

Springer Science and Business Media LLC

Rights

All rights reserved
Sponsorship
Cancer Research UK (23385)
Cancer Research UK