Recommendations for research
We have made the following recommendations for research, based on our review of the evidence, to improve NICE guidance and patient care in the future.
1 Surveillance programmes for people at increased risk of colorectal cancer
How effective are colonoscopic surveillance programmes in improving overall survival and cancer-related survival for people at increased risk of colorectal cancer?
Why this is important
There is no evidence from randomised controlled trials (RCTs) on the effectiveness of colonoscopic surveillance programmes in improving survival for people at increased risk of colorectal cancer. Although there is some observational evidence in people with inflammatory bowel disease (IBD), there is no evidence for people after adenoma removal. RCTs should be done to determine the comparative effect of different surveillance programmes on survival (preferably with a follow-up of 5 years and longer) and quality of life for people at increased risk of colorectal cancer because of IBD or adenomas. Trials should also assess any differential effects associated with risk category (as defined in this guideline).
2 Natural history of progression to colorectal cancer for people at increased risk
What is the natural history of progression to colorectal cancer for people with IBD or adenomas?
Why this is important
There is very limited evidence on the natural history of progression to colorectal cancer, and how factors such as extent of disease, grade of dysplasia and adenoma-related factors affect progression. Long-term studies (ideally with a follow up of 20 years or longer) should be done to determine the natural history of colorectal cancer for people with IBD or adenomas.
3 Effectiveness of biomarkers for determining level of risk of colorectal cancer
Which biomarkers, including epigenic and genetic markers, are predictors of colorectal cancer? How should these be used to improve risk stratification?
Why this is important
There is no high-quality evidence on the predictive value of biomarkers, including epigenic and genetic markers, for colorectal cancer for people with IBD or adenomas. Research should be done to identify the biomarkers that are predictive of colorectal cancer, if any can improve levels of early detection, and how they can be used to improve risk stratification.
4 Adenoma types and risk of colorectal cancer
Does the risk of colorectal cancer depend on the type of adenoma?
Why this is important
There is no high-quality evidence on the association between risk of colorectal cancer and some adenoma types (sessile, hyperplastic non-adenomatous). Research should be done to determine if the level of risk of colorectal cancer depends on the adenoma type.