At this year’s CRUK Early Diagnosis Conference in Birmingham, Judith Strachan presented her poster entitled: GP Referral Rate and Clinical Outcome of Patients According to FIT Result.
Introduction
Faecal Immunochemical Tests (FIT) use specific antibodies against intact human haemoglobin and early breakdown
products to quantify the amount of blood in faecal samples (f-Hb).
There is increasing and compelling evidence for the use of FIT to measure f-Hb in the triaging of patients with new
bowel symptoms.
All of the published studies generally show that FIT with a low cut-off has a high clinical sensitivity for colorectal cancer (CRC). Thus a high result should trigger a rapid referral for colonoscopy or similar investigations. Conversely, a low or undetectable FIT result alone has been shown to have a very high negative predictive value for CRC and other significant bowel disease.
In the NHS Tayside Board area, FIT-KITS, supplied by Alpha Laboratories, along with patient instruction leaflets, have
been available to GP practices since 2015. Patients are provided with a pictorial instruction leaflet and requested to
return the completed FIT specimen collection device as soon as possible to the GP facility and, from there, the
devices are delivered to Blood Sciences, Ninewells Hospital and Medical School, Dundee, at ambient temperature, by the routine sample collection service and, if required, stored at 4oC prior to analysis on an HM-JACKarc analyser.
GPs are recommended by local and national referral guidelines to request f-Hb to guide referral of patients with any new lower GI symptoms and to use 10 µgHb/g faeces as the cut-off decision point. A FIT ≥400 µgHb/g warrants an urgent referral.
