Effect of multiple loading FIT sample collection devices on faecal haemoglobin concentration

Area of Science:

• Clinical Chemistry
• Gastroenterology
• Cancer Screening

Background:

• Faecal immunochemical tests (FIT) are vital for colorectal cancer (CRC) screening.
• Quantitative FIT aids in triaging symptomatic patients in primary care.
• Faecal sample collection devices (SCDs) with internal collars are used for sample collection.

Purpose of the Study:

• To investigate the impact of multiple sample loading on faecal haemoglobin (f-Hb) concentration.
• To assess this impact across four different FIT systems.
• To evaluate the effect of mixing versus no mixing between sample loads.

Main Methods:

• f-Hb negative samples were spiked with blood and homogenized.
• Samples were loaded 1, 3, and 5 times into SCDs, with and without mixing between loads.
• f-Hb was measured using the respective FIT systems, comparing multiple loads to a single load.

Main Results:

• Multiple loading (1-3 and 1-5 times) significantly altered f-Hb mass and concentration (p < 0.05) for all tested systems.
• The median percentage change in f-Hb was higher in the mixed sample group compared to the unmixed group.
• Significant differences were observed between mixed and unmixed groups for both 1-3 and 1-5 load scenarios.

Conclusions:

• Multiple loading into SCDs significantly increases f-Hb measurements.
• This effect impacts the accuracy of quantitative FIT results.
• Careful consideration of sample loading procedures is necessary for reliable CRC screening.