Predicting the impact of the screening programme for colorectal cancer in the UK

Abstract

Screening for colorectal cancer by biennial testing for faecal occult blood is being introduced in the UK from 2007. We examine the likely impact of the programme, in terms of reduced mortality, lives saved and changes in incidence, over the next 20 years. Projections of incidence and mortality of colorectal cancer in England, and the policy that has been adopted for screening in England (biennial at ages 60-69 from 2007, then 60-74 in 2010). The results are based on the output of a simulation model that has been used to examine cost-effectiveness of screening policy options, with two scenarios regarding compliance with screening; both assume that 20% of the population will never attend for screening, but attendance of those who do is modelled either as a random 60% or 80%, at each screening round. The decrease in mortality rates expected 20 years after introducing screening is 13-17% in men and 12-15% in women (depending on the attendance levels). The model predicts an initial rise in incidence, followed (after six to seven years) by a fall, so that there is little net change in the number of cases detected over a 20-year period. Percentage changes in mortality seem modest, but the projected saving in terms of numbers of lives is not negligible--1800-2400 per year by 2025 in England (equivalent numbers are 2200-2700 in all over the UK). Newer screening modalities may improve on these projected results.