Watch for interval cancers with FOBT

Interval cancers may occur in bowel cancer screening and therefore a negative FOBT test should not be taken as a sign that all is well, UK clinicians have warned.

Writing in the BMJ this week, British doctors say that up to a quarter of colorectal cancers identified in an audit occurred in patients who had a negative FOBT.

Their analysis was of data from a single area in the National Bowel Cancer Audit programme where people between the ages of 60 and 70 have FOBT screening every two years.