Interval colorectal cancer risk by haemoglobin concentration in Australia's National Bowel Cancer Screening Program

In Australia’s NBCSP, interval colorectal cancer risk after negative FIT rises sharply with higher negative-range faecal haemoglobin, reaching an adjusted HR of 14.93 for >15–<20 ug/g.

• Why it matters: Interval CRCs are a key indicator of screening performance, yet risk heterogeneity after negative FIT—and how it relates to faecal haemoglobin—remains unclear for NBCSP participants.
• What they did: A retrospective cohort linked Queensland NBCSP screening and cancer registries for ages 50–74 screened in 2018–2022, analyzing 1,083,149 negative episodes with f-Hb <20 ug/g in both samples.
• The result: Across 2,056,405 person-years, 586 interval CRCs occurred (incidence 28.5 per 100,000 person-years; 24-month cumulative incidence 57.6 per 100,000 episodes), and >15–<20 ug/g corresponded to 504.5 per 100,000 episodes.