Reducing the number of surveillance colonoscopies with faecal immunochemical tests

The results indicate that replacing 3 yearly colonoscopy with annual FIT (with a positivity threshold of 40 µg Hb/g faeces) would result in cost savings over the screening cycle of £4.7 million reflecting an 87% reduction in colonoscopies. However, such an approach would miss up to 41% of interval cancers and 67% of advanced adenomas. Modelling a lower FIT positivity threshold (10 µg Hb/g faeces) suggests that the strategy would reduce colonoscopies by 71% but would still miss 28% of cancers and 43% of advanced adenomas. Regardless of the financial savings, such a clinical outcome is likely to be deemed unacceptable. In addition to the medical consequence of missed lesions, patient acceptability of such a change to surveillance is also an important factor. Our initial results in a survey of intermediate risk patients undergoing colonoscopy and FIT within our long-term colonoscopy surveillance programme (SCOOP2 3) found that 79% were uncomfortable with the concept of FIT replacing colonoscopy.