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

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).

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.