Guidelines update: use of FIT in colorectal cancer referrals

The guideline

In July, the British Society of Gastroenterology issued new guidance on the use of faecal immunochemical testing (FIT) to optimise referral pathways for patients with signs and symptoms of colorectal cancer (CRC).

Published in the BMJ and produced jointly with the Association of Coloproctology of Great Britain and Ireland, the guidance is aimed at helping GPs to prioritise the highest-risk patients for urgent referral.

It may also reduce unnecessary referrals that otherwise could divert resources and processes away from patients with the most significant risk of CRC, the authors said.

According to the guidance, FIT should be a triage tool to help determine whether to refer patients under a ‘fast-track’ CRC cancer pathway. If patients have symptoms but do not meet the criteria for urgent referral, they can potentially be managed in primary care.

Key points for GPs

Using FIT in primary care

• GPs should use FIT as a triage tool to help determine whether to refer patients under a ‘fast-track’ cancer pathway, with a threshold of fHb ≥10 µg Hb/g.
• Patients who have fHb ≥10 µg Hb/g and lower gastrointestinal tract symptoms should be selected for an urgent referral pathway for CRC investigation.
• Those with fHb <10 µg Hb/g can potentially be managed in primary care assuming adequate safety-netting is in place.
• Patients who do not meet the FIT result threshold may still be eligible for referral to secondary care – either routinely or on another urgent pathway – in cases where ‘referral is appropriate for other reasons’.
• Patients with persistent or recurrent anorectal bleeding and fHb <10 µg Hb/g should be referred for flexible sigmoidoscopy.
• GPs can use FIT to determine how urgently to refer patients with iron-deficiency anaemia.

Where patients have not returned a FIT sample

• GPs should follow up patients who haven’t returned a sample, or who decline FIT, to encourage them to submit a sample in order to complete the evaluation of their symptoms.
• They should follow existing national and local guidelines to assess CRC risk in patients for whom no FIT can be obtained.

Managing below-threshold patients

• Safety-netting should be in place to ensure patients with lower gastrointestinal symptoms suggestive of CRC, but whose FIT does not meet the urgent referral threshold, can be managed appropriately in primary care.
• If GPs are concerned about a patient with an fHb <10 µg Hb/g but who continues to have unexplained symptoms, they should refer the patient to secondary care – either on a routine or urgent referral.

The BSG has published a simplified flow-chart outlining their recommendations on use of FIT in referrals for suspected CRC, available here.

Practical issues

The guidelines follow advice from NHS England, issued in January, that GPs ought to accompany all urgent referrals for suspected lower gastrointestinal cancer with a FIT result.

However, that and the BSG’s recommendations contradict the NICE NG12 guideline on recognition of and referral for suspected cancer, which sets out several scenarios in which patients should be referred for urgent investigation without requiring FIT.

The likelihood is that GPs will still urgently refer the highest-risk patients who meet the top-line NICE criteria, regardless of the FIT result.

But the BSG guidance could prove confusing here: If GPs wait for a FIT result before making the referral, the referral will inevitably be held up. If they order a FIT in parallel with making the referral, problems may follow if the patient doesn’t complete the test or if the test is lost.

It’s unclear whether, in this case, it would fall to secondary care to chase up, or whether that would land back on the GP referrer’s desk. Both scenarios ultimately increase workload.

Of note, Pulse is aware that in some areas GPs are currently being asked to arrange FIT at the point of referral. This does not affect the urgency of their initial referral, but secondary care use the FIT result as a triage tool to stratify the urgency of investigation. For example, a FIT negative patient on an urgent, two-week wait referral will be contacted within two weeks by the hospital, but will wait longer to be seen for their investigation than a FIT positive patient referred under a two-week wait.

The BSG recommends that an education programme be developed to facilitate implementation of FIT as a diagnostic triage tool in primary care. But detail is lacking on what that education might look like, and who would be tasked with developing it.

Expert comment

Watford GP and committee member (formerly chair) of the Primary Care Society for Gastroenterology (PCSG), Dr Kevin Bartlett, says: ‘Overall, I think the new guidance is a positive thing and I suspect it will result in those patients who are at higher risk of cancer being investigated more rapidly.

‘There will always be a very small number of patients who have a negative FIT test but do have cancer, so there must be appropriate safety-netting for those patients.

‘The problem is that call and recall systems in primary care are inadequate. So, it’s tricky for GPs to follow up patients without robust processes for doing so. Routine gastroenterology appointments can take many months and it’s very hard for us to access care for those patients, and no consistent pathway.

‘The PCSG has done some work with Crohn’s and Colitis UK and the RCGP around diagnosis of IBD, and there is now an opportunity to build on that and the latest BSG guidance to develop a more comprehensive pathway to investigate lower gastrointestinal symptoms.’

Guideline reference:

Monahan KJ, Davies MM, Abulafi M, et al. Faecal 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