Colorectal cancer screening with the addition of flexible sigmoidoscopy to guaiac-based faecal occult blood testing: a French population-based controlled study (Wintzenheim trial)

Abstract

Objective: To assess the feasibility, participation and neoplasia yield of adding a flexible sigmoidoscopy (FS) once in a lifetime to a colorectal cancer screening programme with guaiac-based faecal occult blood test (gFOBT).

Methods: A total of 4771 average risk residents aged 50-74 of a canton of the Haut-Rhin, a French administrative area, were invited every other year to participate in an organised screening programme with gFOBT. Of them, those aged 55-64 (1824 people) were, in addition, invited once by mail to visit their general practitioner (GP) for a screening with FS performed by a gastroenterologist.

Results: In all, 2717 people (56.9%) (95% confidence interval (CI) 55.5-58.4) were screened with one or other of the two tests or with both tests. Compliance was 56.7% (55.3-58.1) with gFOBT and 20.9% (19.1-22.8) with FS. Both tests were performed by 20.2% (18.4-22.1) of people. Compliance with FS was 1.9% in people who had not complied with gFOBT and 31.9% in people who complied. The latter was 50% in patients of 26 motivated GPs. The detection rate for advanced neoplasia was 17.7 per 1000 people screened (12.7-22.6) with the combined procedure, more than three times higher than that with gFOBT alone.

Conclusion: A population-based screening programme with the addition of FS to gFOBT is feasible and safe through an organisation involving GPs. The performances of the two screening tools are complementary: high compliance - low yield for gFOBT and vice versa for FS. The addition of a single FS screening in people aged 55-64 to an organised programme with biennial gFOBT in people aged 50-74 is a colorectal cancer screening option that deserves further exploration.