Journals Club - Colorectal cancer screening

By Dr Louise Newson on the 18 November 2010

Dr Louise Newson brings us up to date with the latest research and guidance on colorectal cancer screening.

Curriculum statement 5 - Healthy People: promoting health and preventing disease.

Key trials

The incidence of colorectal cancer (CRC) has increased in recent decades. Screening for CRC is important because it is a disease with high prevalence, has recognised precursors and early treatment is beneficial (Best Pract Res Clin Gastroenterol 2010; 24: 417-25).
One study showed that screening could save up to 2,400 lives every year in the UK by 2025. This means home testing kits could reduce deaths by about 16 per cent (J Med Screen 2008; 15: 163-74).
Testing for faecal occult blood and measurement of serum tumour markers, such as carcinoembryonic antigen, are not useful in the investigation of suspected colorectal cancer (BMJ 2007; 335: 715-8).
There have been technical advances in stool DNA testing so this may be used for screening in the future (J Clin Gastroenterol 2010 Sep 17. Epub ahead of print).
However, the new technologies of stool DNA testing (CT colonography and capsule endoscopy) are not yet cost-effective compared with the established screening (Best Pract Res Clin Gastroenterol 2010; 24: 439-49).

Evidence base

National guidelines for patients with IBD recommend that colonoscopic surveillance should begin after eight to 10 years for pancolitis and 15 to 20 years for left-sided disease. (Gut 2002; 51(Suppl V): v10-v12).
However, a Cochrane review did not find conclusive evidence that surveillance colonoscopy prolongs survival in patients with colitis (Cochrane Database Syst Rev 2006; (2): CD000279).
Following a colonoscopy after screening, about five in 10 people who have a colonoscopy will have a normal result, about four in 10 will be found to have a polyp, which if removed may prevent cancer developing, and about one in 10 people will be found to have cancer (NHS bowel cancer screening programme www.cancerscreening.nhs.uk).

Guidelines

British Society of Gastroenterology guidelines for colorectal cancer screening in high risk groups. http://gut.bmj.com/content/51/suppl_5/v1.full

Useful websites

Key Points
Colorectal cancer is common. If bowel cancer is detected at the earliest stage there is more than a 90 per cent chance of survival. Patients with IBD have an increased risk of bowel cancer. Newer tests, for example stool DNA testing, may be introduced in the future. Colorectal cancer screening is effective in the UK.