1 Recommendations
1.1
Quantitative faecal immunochemical testing (FIT) using HM‑JACKarc or OC‑Sensor is recommended to guide referral for suspected colorectal cancer in adults:
-
with an abdominal mass, or
-
with a change in bowel habit, or
-
with iron-deficiency anaemia, or
-
aged 40 and over with unexplained weight loss and abdominal pain, or
-
aged under 50 with rectal bleeding and either of the following unexplained symptoms:
-
abdominal pain
-
weight loss, or
-
aged 50 and over with any of the following unexplained symptoms:
-
rectal bleeding
-
abdominal pain
-
weight loss, or
-
aged 60 and over with anaemia even in the absence of iron deficiency.
FIT should be offered even if the person has previously had a negative FIT result through the NHS bowel cancer screening programme. People with a rectal mass, an unexplained anal mass or unexplained anal ulceration do not need to be offered FIT before referral is considered.
1.2
Refer adults using a suspected cancer pathway referral (as outlined in NICE's guideline on suspected cancer) for colorectal cancer if they have a FIT result of at least 10 micrograms of haemoglobin per gram of faeces.
1.3
For people who have not returned a faecal sample or who have a FIT result below 10 micrograms of haemoglobin per gram of faeces:
-
safety netting processes should be in place
-
referral to an appropriate secondary care pathway should not be delayed if there is strong clinical concern of cancer because of ongoing unexplained symptoms (for example, abdominal mass).
1.4
Clinicians should consider if people need additional help, information or support to return their sample.
1.5
Further research is recommended (see the section on further research) to:
-
determine the clinical impact of using:
-
evaluate methods for improving access, uptake and return of FIT, especially in groups in which engagement is less likely
-
determine how conditions or medicines that increase the risk of gastrointestinal bleeding affect the diagnostic accuracy of FIT.
1.6
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 previous recommendations on testing and referral in NICE's guideline on suspected cancer (see section 2.3). 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.
There is a lack of evidence on using dual FIT in primary care, using FIT in people aged under 40, and using FIT in people who have conditions or medicines that increase the risk of gastrointestinal bleeding. So, further research is needed. Social research is also needed to find the best ways to improve access, uptake and return of FIT in groups that are less likely to return a faecal sample.
People with certain symptoms of colorectal or anal cancer (rectal mass, unexplained anal mass, or unexplained anal ulceration) do not need to be offered FIT before referral (see the recommendations on lower gastrointestinal tract cancers in NICE's guideline on suspected cancer). People who do not return faecal samples or who have a negative FIT result and ongoing unexplained symptoms may still need further investigation in secondary care. This may be through alternative referral pathways such as a non-specific symptoms pathway. It is important that GPs can refer people without a positive FIT result if they think it is necessary.