The first national evaluation of the English bowel cancer screening programme’s effect on stage of colorectal cancer has shown that the programme significantly reduced the risk of advanced stage colorectal cancer, and is therefore likely to achieve its aim of reducing mortality from the disease. Results suggest that people who are screened are 32% less likely to be diagnosed with advanced stage colorectal cancer than those who are invited to screening but do not attend.
Around 35,500 colorectal cases are diagnosed and 13,500 colorectal cancer deaths occur each year in England. The English screening programme began in 2006, offering biennial guaiac faecal occult blood testing to those aged 60-69. The age range was extended to include those aged 60-74 from 2010. This population-based randomised case-control study of screening participants included 14,636 individuals diagnosed with primary colorectal cancer in 2012-13, and 29,036 unaffected individuals (two controls per case, matched on geographic region, sex, date of birth and year of first screening invitation).
Those who were screened had lower odds of advanced (Dukes’ stage D) colorectal cancer (cOR 0.68, 95%CI: 0.50-0.93). The authors estimate that in 100,000 people screened biennially between ages 60-74, 435 fewer advanced colorectal cancer cases occur by age 80 than in a similar unscreened group. Corresponding author Professor Stephen Duffy said: “This study shows that the NHS bowel screening programme is likely to achieve its aim of reducing mortality from the disease. We now use faecal immunochemical testing, which is more sensitive to both cancer and pre-cancer, so the benefits of the programme in future are likely to be even greater than those we observed.”
Castanon A, Parmar D, Massat N, Sasieni P, Duffy SW. Benefit of biennial faecal occult blood screening on colorectal cancer in England: A population-based case-control study. JNCI: Journal of the National Cancer Institute. 2022