O138 Diagnostic and prognostic factors associated with faecal haemoglobin concentration in a symptomatic cohort

Abstract

Abstract Introduction There is limited evidence regarding FIT and colorectal cancer (CRC) site, stage, grade and anaemia in the symptomatic cohort. Primary aim is to determine whether an association exists between FIT (analysed with OC-Sensor™ Pledia) and these diagnostic/prognostic factors. Secondary aim was to compare continuous versus categorical FIT, to determine the difference when reporting to upper limit of quantification (some centres do not report FIT >200 (μg Hb/g faeces)). Methods Symptomatic two-week wait CRC with FIT were grouped into thresholds (<10, 10-200 and >200) and analysed using Chi-squared test. Mann-Whitney U test (p≤0.05) compared median FIT in sex, stage, grade and site (right-sided (R-CRC): caecum to transverse colon/ left-sided (L-CRC): splenic flexure to rectum). Pearson's correlation compared FIT and continuous variables (haemoglobin, mean corpuscular volume and ferritin). Results 114 patients (57F:57M); 46 R-CRC (FIT=113) vs 68 L-CRC (FIT=342) (p=0.07), 69 moderately differentiated CRC (FIT=183) vs 29 poorly differentiated (FIT=866) (p=0.004). 35 early stage (T1/2) (FIT=170) vs 79 advanced (T3/4) (FIT=200) (p=0.06). Ferritin <30ug/L correlated with higher FIT (p=0.18). When grouped into FIT thresholds, each association became less significant. Conclusion Left-sided, poorly differentiated and advanced stage CRC is associated with higher FIT. There appears benefit in reporting FIT to the upper limit of quantification in symptomatic patients, as this may allow greater differentiation and earlier investigation of those with adverse CRC prognostic features. The presence of low ferritin reinforces the diagnostic value of elevated FIT. Given these findings, FIT may have a role in risk stratification for CRC beyond diagnosis alone.