Sustained participation, colonoscopy uptake and adenoma detection rates over two rounds of the Tallaght-Trinity College colorectal cancer screening programme with the faecal immunological test.

BACKGROUND: Studies to date support the use of the faecal immunological test (FIT) in colorectal cancer screening programmes, and it has been widely adopted across Europe, Canada, Australia, and the USA. Successive screening rounds are necessary to detect and prevent colorectal cancer. The overall success of FIT screening will depend on several factors, the most important probably being the acceptability of repeated screening rounds. Being a newer form of occult blood testing, there is little data available on its overall efficacy over time.

AIMS: The aim of this study was to assess key performance indices during a second round of FIT screening in an Irish cohort and to compare results between successive rounds.

METHODS: A biennial, two tests, two-step design with postal invites and colonoscopy offered to anyone with a single FIT greater than 100 ngHb/ml was used. Recommended key performance measures were assessed and compared, including participation, positivity, colonoscopy uptake and adenoma and cancer detection rates.

RESULTS: In round two, 9863 individuals (98.6%) of the round one cohort were contacted. The round two participation rate was 47.5% (n=4685), only slightly lower than the 51% registered in round one. Male sex and younger age were associated with lower uptake. Overall positivity decreased from 10 to 8% over time (P<0.0001). Although the number of cancers detected during round two decreased significantly, overall neoplasia detection rates remained stable; positive predictive values for cancer and adenoma were 4 versus 1% and 37 versus 35%, respectively.

CONCLUSION: Repeated rounds of FIT screening in the Tallaght-Trinity College cohort achieved stable participation and neoplasia detection rates, suggesting that this mode of screening is both effective and acceptable to patients in the long term.