Impact case study database

Colorectal cancer is the second commonest cause of cancer death in both sexes, killing ~1,600 people in Scotland each year. The Scottish Bowel Screening Programme, of which Steele has been Clinical Director since its implementation, started in 2007; between 2008 and 2018 colorectal cancer mortality in Scotland fell by 8%. By October 2018 ~6,000 colorectal cancers had been diagnosed through screening [E1].

Steele is the Independent Chair of the UK National Screening Committee (UKNSC), which advises UK  ministers and the NHS on population screening. In this role “he has been particularly helpful in navigating the policy positions in bowel screening… and facilitated an excellent and evidence-based outcome.” [E2].

The Scottish Bowel Screening Programme has been exemplary for similar programmes in other countries. The European Guidelines for Quality Assurance in Colorectal Cancer Screening and the International Agency for Research on Cancer (IARC) Handbook of Colorectal Cancer Screening [E3], to both of which Steele made major contributions, drew heavily on experience gained in Scotland and the rest of the UK. Steele’s evidence contributed to the IARC conclusion “There is sufficient evidence that biennial screening with the faecal immunochemical test (FIT) reduces colorectal cancer mortality. …[and]… that the benefits of biennial screening with FIT outweigh the harms when the screening programme can be delivered with high quality.” [E3, p298]. This evidence has been used to support use of the FIT in colorectal cancer screening programmes across the world.

Introduction of the FIT in Scotland and the UK

From 2007-2017 the FIT was used to follow up weak positive faecal occult blood test results in Scotland, Wales and Northern Ireland. In January 2016 the UKNSC recommended quantitative FIT as the primary method for colorectal cancer screening nationwide. The Scottish Bowel Screening Programme made this change in November 2017 [E4]; by the end of 2020 England, Wales and Northern Ireland had also adopted the FIT for their national bowel cancer screening programmes [E5].

Uptake of screening invitations increased by ~10% in the year following introduction of quantitative FIT screening in Scotland. This was associated with a 64.8% increase in the detection rate for adenomas (1.02% vs 0.62% of the screening population with an adenoma) and a small increase in the detection rate for carcinomas (0.12% vs 0.11% of the screening population with a carcinoma) [E1].

Contribution of the FIT to diagnosis in symptomatic patients

The presenting symptoms of colorectal cancer resemble those of numerous benign, self-limiting conditions. The challenge, therefore, is to achieve early diagnosis of neoplasia against this background of non-cancerous disease, thus avoiding unnecessary investigation which can cause trauma and discomfort to patients, is a drain on resources and puts pressure on service providers.

Demand on colonoscopy services has recently increased enormously, driven by increasing awareness of these symptoms and waiting time targets. This has not, however, translated into improved early detection. Non-endoscopic methods which can identify all, but only, those patients who require full investigation are therefore essential. Steele’s group has demonstrated that quantitative FIT can be used to rule out colorectal neoplasia in symptomatic patients. This concept was incorporated into NICE guidelines in 2017 [E6].

Research on this use of quantitative FIT demonstrated, over the first year of its implementation in NHS Tayside, a 20% reduction in colonoscopy referrals without appreciable failure to detect neoplasia. The quantitative FIT was added to the diagnostic process for symptomatic individuals across Scotland in July 2020 [E7]; this has been particularly valuable in reducing the need for face-to-face appointments during the COVID-19 pandemic.

Moving away from flexible sigmoidoscopy for colorectal cancer screening

Flexible sigmoidoscopy is an effective screening method for colorectal neoplasia. In England it used to be offered at age 55 before the faecal occult blood test (now replaced by the FIT) was offered at 60; however, significant uptake, delivery and quality issues were experienced. The benefits of population-based endoscopic screening were therefore questioned, especially given that the UKNSC now recommends FIT screening from age 50 (i.e. including the age at which endoscopy is offered) [E8]. A randomized trial by Steele’s group demonstrated that the benefits of flexible sigmoidoscopy as an adjunct to faecal occult blood test screening did not justify its introduction into the Scottish Bowel Screening Programme [E9]. Flexible sigmoidoscopy was not, therefore, adopted for screening in Scotland and in July 2020 the UKNSC recommended the permanent discontinuation of endoscopic screening in England [E10].

In summary, Steele and his team have driven improvements in colorectal cancer screening in Scotland and across the UK. They championed the FIT, which is easier to use and more sensitive than the faecal occult blood test, enabling signs of colorectal cancer to be detected earlier, saving more lives. They have also provided evidence against the need for endoscopy in screening and early diagnosis; as well as avoiding the need for an intrusive and often uninformative procedure, this could ”save the NHS millions, as each colonoscopy costs the NHS £372 compared to about £5 for the FIT test” (2017 figures) [E11].