Colonoscopy-ascertained prevalence of advanced neoplasia according to fecal Hb concentration in a cohort of FIT-negative screening participants

Screening could prevent a large proportion of colorectal cancer (CRC) cases and deaths. FITs for hemoglobin (Hb) are increasingly used. Time intervals after which a negative FIT should be repeated among persons at low risk are debated. Risk stratification could be done by quantifying fecal Hb concentration. A study among participants of screening colonoscopy in Germany investigated colonoscopy-ascertained prevalence of advanced neoplasia (AN: CRC or advanced adenoma) according to fecal Hb concentration in a cohort of 6661 screening participants. Forty-one percent and 81% of participants had Hb concentrations below 1.7 and less than 8 μg/g feces, respectively, while 10% were FIT-positive with Hb concentrations greater than 17.7 μg/g. Prevalence of AN increased from 6% among those with Hb concentrations less than 1.7 μg/g to 22% in the group with highest concentration but below the FIT-positivity threshold, and up to 51% among participants with FIT-positive results. The authors conclude that determining fecal Hb concentrations may allow for discriminating between lower-risk and higher risk participants after a negative FIT, and personalizing appropriate FIT intervals.