Sensitivity of Fecal Immunochemical Test (FIT) for Colorectal Cancer (CRC) Screening

Study Overview
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Brief Summary
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Fecal immunochemical test (FIT) was introduced in France late 2015, FIT has better diagnostic accuracy for colorectal cancers (CRCs) than previous screening tests. Our primary objective was to evaluate the sensitivity of FIT and the proportion of interval cancer.

Detailed Description
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Fecal immunochemical test (FIT) aims to detect pre-symptomatic lesions, i.e., early stage colorectal cancers (CRCs) or pre-cancerous lesions such as colonic adenomas in order to reduce CRC mortality. FIT was introduced in France late 2015, FIT has better diagnostic accuracy for CRCs than previous screening tests. Determining the incidence of post-test interval CRCs, diagnosed after a negative FIT and before the recommended date of the next test (2-year interval), allows assessment of the sensitivity of the test. The primary objective of this study was to evaluate the performance of FIT during the CRC screening campaign in the Finistère department (France) from January 1, 2016 to December 31, 2017. Its secondary objectives were the evaluation of diagnostic circumstances and their impact on treatment and survival, and risk factors for interval cancer (IC).

Official Title
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Sensitivity of Fecal Immunochemical Test (FIT) for Colorectal Cancer (CRC) Screening and Interval Cancer Risk : a Population Based Study

Conditions
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Colorectal Neoplasms Malignant, Colonoscopy, Early Detection of Cancer, Female, Mass Screening, Middle Aged, Occult Blood

Intervention / Treatment
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* Diagnostic Test: Positive fecal immunochemical test (FIT)
* Diagnostic Test: Negative fecal immunochemical test (FIT)
* Diagnostic Test: Fecal immunochemical test (FIT) not performed


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All subjects between 50 and 77 years diagnosed with an in situ or an invasive CRC Inhabitants of the Finistère area Subjects were included by period: from January 2016 to December 2017 for subjects with SD-CRC, non-responders and the excluded population from January 2016 to December 2019 for subjects with FIT-ICs (2-year interval) from January 2016 to December 2020 for subjects with post-colonoscopy IC from January 2018 to December 2020 for subjects with delayed diagnosis Exclusion Criteria: Subjects who refused to participate in the case of refusal of data collection Subject swith CRC other than adenocarcinoma were excluded.

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 77 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CRC in excluded population<br>CRC diagnosed in the population excluded from screening | Diagnostic Test: Fecal immunochemical test (FIT) not performed<br>* We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers.<br>|
| Screen-detected colorectal cancers (SD-CRCs)<br>CRC diagnosed after a positive fecal immunochemical test (FIT) | Diagnostic Test: Positive fecal immunochemical test (FIT)<br>* We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers.<br>|
| Colorectal cancers (CRCs) with delayed diagnosis<br>CRCs diagnosed after a positive fecal immunochemical (FIT) test, but without colonoscopy or > 2 years after a positive fecal immunochemical test | Diagnostic Test: Positive fecal immunochemical test (FIT)<br>* We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers.<br>|
| Fecal immunochemical test interval colorectal cancers (FIT IC)<br>CRCs diagnosed 2 years after a negative FIT | Diagnostic Test: Negative fecal immunochemical test (FIT)<br>* We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers.<br>|
| colorectal cancers (CRCs) in non-responders<br>CRCs diagnosed in the FIT non-responders population | Diagnostic Test: Fecal immunochemical test (FIT) not performed<br>* We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers.<br>|
| Post-colonoscopy interval cancers<br>CRCs diagnosed within 5 years after a colonoscopy performed following a positive test that did not find colorectal cancer | Diagnostic Test: Positive fecal immunochemical test (FIT)<br>* We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sensitivity of the fecal immunochemical test for the detection of colorectal cancers | Sensitivity = True positive / True positive + False negative = SD CRCs / SD CRCs + FIT IC | We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Parameters affecting the sensitivity of FIT, risk factors of interval cancer | Age, sex, stages, localizations, comparison by Chi2 or Fisher's test for categorical data and Student's test for quantitative data. Multivariate analysis using logistic regression. | We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers. | 
| FIT value | FIT value, comprised between 10 and 200 µg haemoglobin/g faeces (analytical limits of quantification), | FIT data included its value, comprised between 10 and 200 µg haemoglobin/g faeces (analytical limits of quantification), | 
| Survival | Analysis of survival according to diagnostic circumstances | We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers. | 
| Treatment | Analysis of treatment according to diagnostic circumstances | We evaluated CRCs screening campaign from January 1, 2016 to December 31, 2017, and interval cancers within two years after a negative test, and five years for post-colonoscopy interval cancers. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Screening, Fecal immunochemical test, survival, interval cancer