Fecal immunochemical testing in patients suspected colorectal cancer: ACPGBI and BSG guideline

FIT in primary care

• FIT should be used by primary care clinicians to prioritize patients with clinical features of CRC for referral for urgent investigation.
• A FIT threshold of fHb ≥10 µg Hb/g should be used in primary care to select patients with lower GI symptoms for an urgent referral pathway for CRC investigation.
• Patients should not be excluded from a referral from primary care for symptoms on the basis of FIT testing alone.

Advice for clinicians where patients have not returned a FIT test

• The authors suggest that clinicians should follow up with patients with no FIT result to encourage them to return a sample or, where the kit has been lost or inadequately submitted, offer a further test.
• The authors suggest that patients who decline to return a FIT test should be counseled that the evaluation of their symptoms is incomplete, and be encouraged to complete their test.
• The authors suggest that where no FIT result can be obtained, clinicians should use existing national and local guidelines to assess the risk of CRC.

Safety netting

• The authors recommend that some patients with symptoms of suspected CRC may be managed in primary care if fHb <10 µg Hb/g, and provided appropriate safety-netting is in place.
• The authors suggest that patients with an fHb <10 µg Hb/g but with persistent and unexplained symptoms for whom the GP has an ongoing clinical concern should be referred to secondary care for evaluation.
• The authors recommend that safety-netting protocols should incorporate advice and strategies for the diagnosis of CRC and extracolonic cancer, as well as other serious gastrointestinal conditions.

Diagnostic accuracy of FIT for CRC with suspected cancer signs or symptoms

• FIT is a triage tool to identify those patients with symptoms of suspected CRC who should undergo further colorectal investigation.
• The authors suggest that FIT be used for people with iron deficiency anemia within primary care to inform the urgency of referral.
• The authors suggest referral of patients with persistent/recurrent anorectal bleeding for flexible sigmoidoscopy if fHb <10 µg Hb.
• There is currently insufficient evidence to recommend variations in the fHb threshold for a referral from primary care according to patient related-factors.
• here is currently insufficient evidence to confirm whether diagnostic accuracy is impacted by the type of FIT analyzer used.
• There is currently insufficient evidence to recommend including FIT in a risk score with other clinical features to identify patients with symptoms of suspected CRC.
• The authors suggest that FIT may be used to stratify adult patients aged younger than 50 years with bowel symptoms suspicious of a diagnosis of CRC.

Investigations in secondary care

• Colonoscopy is considered the standard method of investigation, however other methods of colorectal imaging may be appropriate in some patients.
• The authors recommend that for patients with symptoms of a suspected diagnosis of CRC, CT colonography (CTC) is equivalent to colonoscopy for the detection of CRC (the choice of modality should be determined by local expertise and availability).
• There is currently insufficient evidence to support the use of a specific quantitative FIT threshold to recommend the selection of CT colonography versus colonoscopy.

Acceptability

• On the basis of limited evidence, clinicians and patients consider FIT as an acceptable test for symptomatic CRC in most circumstances.
• The authors recommend that services should consider ways of promoting a high proportion of patients to return FIT kits.

Discrimination

• The authors recommend that clinicians actively prevent discrimination at any stage of the diagnostic pathway as symptomatic FIT testing is rolled out, with a focus on equity of access and application to all patients with lower GI symptoms.

Implementation

• The authors recommend that FIT, as a diagnostic triage tool, can be implemented safely at the primary care level and that a program of education is developed to facilitate the implementation of FIT in primary care.

Reference:

Monahan KJ, Davies MM, Abulafi M, et alFaecal immunochemical testing (FIT) in patients with signs or symptoms of suspected colorectal cancer (CRC): a joint guideline from the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the British Society of Gastroenterology (BSG)Gut Published Online First: 12 July 2022. doi: 10.1136/gutjnl-2022-327985