Quantitative Faecal Hb (FHb)

Purpose:
Faecal immunochemical tests (FIT) are designed to detect small amounts of blood in stool samples (faecal occult blood) using antibodies specific to human haemoglobin (Hb). These tests are recommended by NICE to guide referrals for suspected colorectal cancer in symptomatic patients. [DG 30 – quantitative faecal immunochemical tests to guide referral for colorectal cancer in primary care] and in NICE guideline [NG12: Suspected cancer: recognition and referral]. FIT is also recommended by the UK National Screening Committee and has replaced gFOBT as part of the testing strategy for the UK Bowel Cancer Screening Programmes.

NICE DG30: Recommendations (2017)
1.1 The OC Sensor, HM JACKarc and FOB Gold quantitative faecal immunochemical tests are recommended for adoption in primary care to guide referral for suspected colorectal cancer in people without rectal bleeding who have unexplained symptoms but do not meet the criteria for a suspected cancer pathway referral outlined in NICE’s guideline on suspected cancer [NG12 recommendation 1.3.4].
1.2 Results should be reported using a threshold of 10 micrograms of haemoglobin per gram of faeces. Companies should provide advice about the performance characteristics of the assays to laboratories, and ensure standardisation of results.

NICE NG12: Recommendations 1.3 Lower gastrointestinal tract cancers (updated 2021).
1.3.4 Offer testing with quantitative faecal immunochemical tests to assess for colorectal cancer in adults without rectal bleeding who:

are aged 50 and over with unexplained abdominal pain or weight loss,
or are aged under 60 with changes in their bowel habit or iron-deficiency anaemia, or
are aged 60 and over and have anaemia even in the absence of iron deficiency

UK National Screening Committee (2018) recommendation
Screening for bowel cancer should be offered every 2 years to men and women between the ages of 50 and 74 in the UK using the faecal-immunochemical test (FIT).

All 4 nations in the UK offer a population screening programme using FIT, however the screening strategies differ according to the endoscopy capacity available.

The Quantitative FIT EQA programme is designed to assess performance of laboratories undertaking FIT as part of the diagnostic investigation of colorectal cancer in symptomatic patients and in the assessment of specialist centres using FIT for the asymptomatic population screening for colorectal cancer. Weqas also offers a qualitative EQA programme for those laboratories that are still using gFOBT.

Scope:
The base material is organic material which closely mirrors the basic constituents of human faeces to which a known quantity of Hb (as human whole blood) is added. Material at a range of Hb concentrations is prepared to cover the pathological and analytical range for FIT including samples at or near the clinical cut-off of 10 ug Hb /g used for symptomatic testing pathways and the higher cut offs used in asymptomatic population screening programmes. The homogeneous material is dispensed aseptically into buffered vials specific to each instrument manufacturer.

The three samples per distribution is designed to assess laboratory and method performance, including linearity, bias, and within batch imprecision.

Key Features:

Material closely mirrors the basic constituents of human faeces.
FIT samples are pre loaded into buffered collection tubes specific to each instrument.
Covers the pathological and analytical range for quantitative FIT automated analysers.
Samples challenging clinically relevant cut-offs for symptomatic testing pathways.