Quantitative faecal immunochemical testing to guide colorectal cancer pathway referral in primary care

1 Recommendations

1.1 Quantitative faecal immunochemical testing (FIT) using HM-JACKarc or OC-Sensor is recommended to guide referral for adults with signs or symptoms suggestive of colorectal cancer (as outlined in recommendations 1.3.1 to 1.3.4 in NICE's guideline on suspected cancer, excluding those with rectal mass).

1.2 Refer adults using a suspected cancer pathway referral (for an appointment within 2 weeks) for colorectal cancer if they have a FIT result of at least 10 micrograms of haemoglobin per gram of faeces.

1.3 Referral to secondary care should not be delayed in the absence of a FIT result if there is clinical concern.

1.4 Safety netting processes should be in place for people:

1.5 Clinicians should consider if people may need additional help or support to return their sample.

1.6 Further research is recommended (see the section on further research) to:

1.7 Further research is recommended (see the section on further research) on the effectiveness of:

Why the committee made these recommendations

FIT detects small amounts of blood in faeces, which is a sign of possible colorectal cancer. Evidence shows that offering the test in primary care can identify people who are most likely to have colorectal cancer. These people can then be prioritised for referral to secondary care, while people who are less likely to have colorectal cancer can avoid unnecessary investigations. This means that colonoscopy resources can be used for people who most need them.

There is clear evidence on the diagnostic accuracy of the HM‑JACKarc and OC‑Sensor tests. So, the HM‑JACKarc and OC-Sensor tests are recommended. The evidence is less clear for other tests and the estimates of diagnostic accuracy are more uncertain, so further research is needed.

The economic model considers multiple testing strategies for referral across a range of thresholds. All testing strategies using HM‑JACKarc or OC‑Sensor are cost effective compared with the recommendations in NICE's guideline on suspected cancer and NICE's diagnostics guidance on quantitative FIT to guide referral for colorectal cancer in primary care. This is because FIT allows available colonoscopy resource to be used more effectively.

The economic model suggests that using thresholds above 10 micrograms of haemoglobin per gram of faeces for referral is more cost effective than using lower thresholds. But, this is uncertain because there is not enough evidence to support some of the assumptions about safety netting for these higher thresholds. There is also concern that using a higher threshold would reduce physician confidence in the test results (because more people with cancer may be missed) and so affect clinical decision making. Further research is needed on how using higher thresholds would affect clinical outcomes and decision making.

The economic model also considers a testing strategy using 2 faecal samples, but evidence suggests that certain groups are less likely to return any samples. So, asking for 2 samples for FIT could create inequality in access.

Social research is needed to find the best ways to improve uptake and return of FIT in groups that are less likely to return a faecal sample.

People who do not return faecal samples or have negative FIT results may still need further investigation in secondary care. It is important that GPs can refer people without a positive FIT result if they think it is necessary.