Benefit of biennial faecal occult blood screening on colorectal cancer in England: A population-based case-control study
Menée en Angleterre à partir de données portant sur 29 036 témoins et 14 636 personnes atteintes d'un cancer colorectal diagnostiqué entre 2012 et 2013, cette étude évalue le bénéfice, en terme de réduction de l'incidence de la maladie, d'un programme de dépistage biennal comportant un test au gaïac
Background : The English national bowel cancer screening programme(NHSBCSP) offering a guaiac faecal occult blood test (gFOBT) began in July 2006. In randomised controlled trials of gFOBT screening, reductions in mortality were accompanied by reductions in advanced stage colorectal cancer (CRC). We aimed to evaluate the effect of participation in the NHSBCSP on stage-specific CRC incidence, as a likely precursor of a mortality effect.
Methods : Population based case-control study. Cases were individuals diagnosed with CRC aged 60–79 between 1 January 2012 and 31 December 2013. Two controls per case were matched on geographic region, sex, date of birth and year of first screening invitation. Screening histories were extracted from the screening database. Conditional logistic regression with correction for self-selection bias was used to estimate odds ratios (cOR) and 95% confidence intervals by Dukes’ stage, sex and age.
Results : 14,636 individuals with CRC and 29,036 without were eligible for analysis. The odds of CRC (any stage) were increased within 30 days of a screening test and decreased thereafter. No reduction in CRC (any stage) among screened individuals compared to those not screened was observed (cOR 1.00, 95%CI: 0.89–1.15). However, screened individuals had lower odds of Dukes’ stage D CRC (cOR 0.68, 95%CI: 0.50–0.93). We estimate 435 fewer Dukes’ D CRC by age 80 in 100,000 people screened biennially between ages 60–74 compared with an unscreened cohort.
Conclusion : The impact of colorectal screening on advanced CRC incidence suggests that the programme will meet its aim of reducing mortality.
Journal of the National Cancer Institute , article en libre accès, 2021