Adding family history to faecal immunochemical testing increases the detection of advanced neoplasia in a colorectal cancer screening programme.

Abstract

Faecal immunochemical testing (FIT) for colorectal cancer (CRC) screening has suboptimal sensitivity for detecting advanced neoplasia. To increase its performance, FIT could be combined with other risk factors. To evaluate the incremental yield of a screening programme using a positive FIT or a CRC family history, to offer a diagnostic colonoscopy. For this post hoc analysis, data were collected in the colonoscopy arm of a colonoscopy or colonography for screening study. In this study, 6600 randomly selected, asymptomatic men and women (50-75 years) were invited for screening colonoscopy. 1112 Participants completed a FIT and a questionnaire prior to colonoscopy. We compared the yield of FIT-only and FIT combined with CRC family history, defined as having one or more first-degree relatives with CRC. At a 10 μg Hb/g faeces FIT-positivity threshold the combined strategy would increase the yield from 36 (3.2%; CI: 2.4-4.5%) to 53 (4.8%; CI: 3.7-6.2%) cases of advanced neoplasia, at the expense of 148 additional negative colonoscopies. Sensitivity in detecting advanced neoplasia would increase from 36% (CI: 26-46%) to 52% (CI: 42-63%), whereas specificity would decrease from 93% (CI: 92-95%) to 79% (CI: 76-81%). The strategy will be preferred if one accepts 8.8 false positives for every additional participant in whom advanced neoplasia can be detected. Offering colonoscopy to those with a positive FIT or CRC family history increases the yield of a FIT-based screening programme. Depending on the number of negative colonoscopies one accepts, this combined approach can be considered for improving CRC screening.