The Intermediate Adenoma (IA) study and the All Adenomas (AA) study

The Intermediate Adenoma (IA) study started in 2006 and was funded by the NHS National Institute for Health Research Health Technology Assessment Programme (NIHR-HTA) until 2013. The CSPRG were additionally supported by the Bobby Moore fund / Cancer Research UK. This study was initiated to answer research questions that were identified by the Department of Health as a priority area. We anticipated that the results would inform the national and international guidelines that make recommendations for how people with adenomas, or bowel polyps, are monitored to protect them from bowel cancer in the future.

In 2017, the CSPRG received additional funding from the NIHR-HTA to answer research questions on people with low- and high- risk adenomas, in addition to the intermediate-risk group previously investigated, the All Adenomas (AA) study.

The trial is registered with the ISRCTN registry. Its unique number is 15213649.

Our Data Protection and Privacy Notice

Imperial College London is the sponsor for the studies run by the Cancer Screening and Prevention Research Group (CSPRG). We will be using special category, personal information from health care records, either directly from NHS Trusts or via third parties such as NHS Digital, the Office for National Statistics, National cancer registries, including the Welsh Cancer Intelligence and Surveillance Unit, and Information Services Division (Scotland), in order to undertake these studies where we will act as the data controller. This means that we are responsible for looking after your information and using it properly. CSPRG / Imperial College London will keep special category, personal data about you for 10 years after the study has finished.

As a University we use personal data and special categories of personal data to conduct research to improve health, care and services. As a publicly-funded organisation, we have to ensure that it is in the public interest when we use personal data and special categories of personal data from people who have agreed to take part in research or where we have section 251 approval to obtain, process and hold such data.

Your rights to access, change or move your information are limited, as we need to manage your information in specific ways in order for the research to be reliable and accurate. If you withdraw from the study, we will keep the information about you that we have already obtained. To safeguard your rights, we will use the minimum personally-identifiable information possible.

Health and care research should be in the public interest, which means that we have to demonstrate that our research serves the interests of society as a whole. We do this by following the UK Policy Framework for Health and Social Care Research.

When you agree to take part in a research study, the information about your health and care may be provided to researchers running other research studies in this organisation and in other organisations. These organisations may be universities involved in health and care research in this country or abroad. Your information will only be used by organisations and researchers to conduct research in accordance with the UK Policy Framework for Health and Social Care Research.

This information will not identify you and will not be combined with other information in a way that could identify you. The information will only be used for the purpose of health and care research, and cannot be used to contact you or to affect your care. It will not be used to make decisions about future services available to you, such as insurance.

You can find out more about how we use your information by contacting us directly – our contact details are available here, or by contacting the Data Protection Officer for Imperial College London at: dpo@imperial.ac.uk .

Further information can be found via the Imperial College London webpages:





What are the aims of the IA and AA studies?

Current UK guidelines for the surveillance of people found to have bowel polyps classify people into those who are at low-, intermediate- or high- risk of developing bowel cancer in the future. The guideline was developed in 2002 by Professor Atkin (head of CSPRG) and Professor Brian Saunders, a consultant gastroenterologist at St Mark’s Hospital in Harrow, the only hospital in the UK focusing on diseases of the bowel. Professor Saunders is a world expert on colonoscopy examination. In 2011 our guideline was adopted by NICE (the National Institute of Clinical Excellence).

This guideline was developed in 2002 and now needs to be re-examined. People with intermediate-risk bowel polyps are currently recommended to have 3-yearly surveillance colonoscopy. This is likely a good option for some people in the intermediate-risk group, but it may not be the best option for others. For example, there might be a group of people for whom the 3-yearly surveillance colonoscopy is unnecessary. For others, the 3-year interval might be too long and a shorter interval could reduce the risk of a missed polyp developing into more serious disease. Perhaps an interval greater than 3 years might be perfectly safe and effective for others in this group? With many questions unanswered, there is a need for ongoing research into this area to provide the evidence to inform the guidelines used by doctors and screening programmes.

The overarching aim of the IA study is to provide robust evidence to underpin the guidelines for how we monitor people in the intermediate-risk group, and make improvements if necessary. We also want to provide insights into the psychological impact of having surveillance on patients and costs to the NHS.

The AA study will provide further evidence to support an update of the guidelines for monitoring people with any type of bowel polyp, and investigate the potential cost implications to the NHS.

We hope that our research will be used to help ensure patients get the best possible care and to enable NHS resources to be used in the most sustainable way.

What type of studies are the IA and AA studies?

The IA and AA studies are observational, retrospective cohort studies. They make use of data from actual/real health examinations, rather than setting up a trial in which people are randomly assigned to a particular procedure or protocol. Observational studies can evaluate risk factors for disease which are then statistically analysed to answer a pre-specified research question. Because the IA and AA studies collect information on procedures that have already happened, they are called ‘retrospective’ studies.

What is an adenoma and what happens if adenomas are found?

The majority of cancers in the large bowel (bowel or colorectal cancers) originate from growths called adenomas or polyps on the inner surface of the bowel. Bowel polyps are common, especially as people get older, and are usually not cancerous; however, a proportion do develop into cancer so they are generally removed when found. Bowel polyps are often found during a colonoscopy examination, which someone might have because they have symptoms that their doctor thinks should be investigated or because they have had a positive test result in a bowel cancer screening programme.

A colonoscopy involves a flexible tube with a camera attached being inserted into the rectum and through the bowel to examine the inside of the bowel. Sometimes, large (1cm or larger) or multiple polyps are found in the same individual. We know from previous research that people with large or multiple polyps are at higher risk of developing more polyps or bowel cancer in the future.

Risk groups based on findings during a colonoscopy examination:

  • For people with 1 or 2 small polyps, their risk is classed as ‘low’. Current guidelines recommend that most people in the low risk group do not require a follow-up colonoscopy. A small number of people may require a follow-up colonoscopy after five years based on other factors such as their age, family history or other illnesses – this is called a surveillance colonoscopy.
  • For people with 3 to 4 small polyps or 1 to 2 large polyps, their risk is classed as ‘intermediate’. Current guidelines recommend that everyone in the intermediate risk group is offered a follow-up colonoscopy after three years.
  • For people with 5 or more small polyps or more than 3 polyps of which at least 1 is large, their risk is classed as ‘high’. Current guidelines recommend that everyone in the high risk group is offered a follow-up colonoscopy after one year.

Surveillance colonoscopy is currently the standard way to monitor people at higher risk of bowel cancer. However, we know that significant disease will only be found in a small proportion of surveillance colonoscopies, which is important because colonoscopy also carries a small risk of complications for patients and is demanding on NHS resources.

What type of information does the CSPRG hold for the purposes of the IA and AA studies?

We have collected information on about 260,000 men and women from sources in the UK and abroad for the purposes of this study. We have used information from people who were investigated by colonoscopy because they had a positive test in a bowel cancer screening initiative, or because they had been referred by their doctor for investigation of their bowel symptoms.
The list below details from where and for which periods of time we have collected this information, or provides links to where this information can be found:

  • 17 hospitals in the UK (see table below) for colonoscopy procedures performed between 1972 and 2010. These hospitals were the source of most of the information we have used for the IA study. From these hospitals we have data on approximately 250,000 men and women. The hospital data collected for the IA study is de-identified, and a file that links our unique study number to the patient identifiers is held at the individual hospital where the data was collected from. No identifiers are held by the research group at CSPRG. The only personal information that we hold is full date of birth for the purpose of ensuring data integrity so that we can validate or query discrepancies in any follow-up data that we receive for these patients from other data sources. We do not hold the names or addresses for anyone whose information was used for this study and it will not be possible to identify individuals from the published results of this study. The clinical data collected consists of endoscopy reports, pathology reports, bowel cancers and deaths data. During analysis of our results we realised that, as the coding and analysis of data for this study took significantly longer than we anticipated, there is a gap in time between the period for which we collected data on bowel cancers and deaths from NHS Digital and the study period for which we collected data on patients procedures from the hospitals involved in the study. Therefore we need to obtain an update on the procedures that occurred during the more recent missing time period not covered by the original data collection. Hospital dataset: 17 UK hospitals where data was collected from:
    Trust Hospital Approximate date range of data collected
    Brighton & Sussex University Hospitals NHS Trust Royal Sussex County Hospital May 2001-
    Apr 2008
    London North West Healthcare NHS Trust St Mark’s Hospital Jan 1972-
    Jul 2007
    Greater Glasgow and Clyde NHS Trust Glasgow Royal Infirmary Apr 1996-
    Aug 2009
    Imperial College Healthcare NHS Trust Charing Cross Hospital/ Hammersmith Hospital Oct 1997-
    Nov 2007
    Imperial College Healthcare NHS Trust St Mary’s Hospital Jan 1985-
    Jul 2010
    North Cumbria Acute Hospitals Trust Cumberland Infirmary Oct 1998-
    Sep 2009
    Queen Elizabeth Hospital NHS Trust Queen Elizabeth Hospital Oct 1999-
    May 2006
    Queen Mary’s Sidcup NHS Trust Queen Mary’s Hospital Oct 1988-
    Jul 2009
    Royal Liverpool and Broadgreen University Hospitals Trust Royal Liverpool University Hospital Jan 2000-
    Sep 2009
    Royal Surrey County Hospital NHS Trust Royal Surrey County Hospital Sep 1997-
    May 2010
    Royal Wolverhampton Hospitals NHS Trust New Cross Hospital Jan 1993-
    Nov 2007
    Shrewsbury and Telford Hospitals NHS Trust Royal Shrewsbury Hospital Dec 2001-
    Sep 2009
    South Devon Healthcare NHS Foundation Trust Torbay District General Hospital Oct 2000-
    Aug 2007
    St George’s Healthcare NHS Trust St George’s Hospital Feb 1992-
    Jul 2009
    University Hospital of North Tees Trust University Hospital of North Tees Jun 1986-
    Dec 2006
    University Hospitals of Leicester NHS Trust Leicester General Hospital Apr 1998-
    Mar 2008
    Yeovil District Hospital Foundation Trust Yeovil District Hospital Feb 1997-
    May 2008

    The AA study will re-use the data from the IA study ‘Hospital dataset’ and update the follow-up period to the end of December 2016, where possible, to give 10 years of follow-up data. To help us understand the cost implications, we will also ask for information on the type of bowel cancers that have occurred in this group of patients. This new information will be requested from Public Health England and the NHS National Services Scotland.

  • The UKFSST screening trial includes data on 2,051 people who were randomised, attended their screening appointment and had a colonoscopy at baseline. We used clinical data (including endoscopy, pathology, cancers and deaths) on these people.
  • The English Bowel Cancer Screening Programme pilot dataset includes 943 men and women who were aged 50 to 69 years old between 2000 and 2002 and who were referred for follow-up following colonoscopy for a positive Faecal Occult Blood Test (FOBt). We used the data from 3 pilot centres that collected data from follow-up colonoscopies. We obtained cancer and mortality data for these individuals with the help of NHS Digital. The only personal data we now hold is full date of birth.
  • The Kaiser Permanente Colorectal Cancer Prevention Program provided data on 2,203 men and women in the United States who attended bowel cancer screening from 1994 and were entered into a surveillance programme. This data is fully anonymised and we hold only clinical data and cancer and mortality data.
  • What approvals has this study received?

    The IA study uses historical data collected for a very large group of patients (over 260,000) so it was not possible to ask for consent from each individual. We received permission to conduct this research study from the independent ethical review committees and organisations responsible for the data of NHS patients and research involving NHS patients listed below:

    • Royal Free Research Ethics Committee (REC)
    • Section 251 approval from the Patient Information Advisory Group (PIAG – a predecessor of both the National Information Governance Board/NIGB and the Confidentiality Advisory Group) in England, and equivalent panels in Scotland, the Community Health Index Advisory Group (CHIAG) and the Privacy Advisory Committee (PAC) of National Services Scotland (NSS)
    • Research and Development approval from the NHS Trusts managing all hospitals involved in the study
    • Approval from the Caldicott Guardian of the North West London NHS Trust
    • Approval from the UK Association of Cancer Registries

    In 2017, we submitted an amendment to the IA study to include the AA study objectives and have received approval from:

    • London – Hampstead Research Ethics Committee (previously Royal Free REC)
    • NHS Health Research Authority, including section 251 approval
    • Other amendment / applications are in progress for the AA study

    Our Patient Data page provides details on some of these bodies.

    How long will we retain the data?

    As the IA study has recently been amended to include the AA study objectives, the study duration has been extended. We will complete the collection of data for these studies in 2018. It is a requirement of Imperial College London, which is the organisation responsible for this study, that we hold data from all clinical research for 10 years after the study end date. We therefore plan to hold the data for this study until 2028.

    What are the results of the study and what impact have they had?

    The results of the IA study have recently been published in The Lancet Oncology and the NIHR-HTA Journal.

    In summary, follow-up with at least one colonoscopy examination is of benefit to most patients who have intermediate-risk bowel polyps detected. However, some people (about a third) are already at a low risk of developing more bowel polyps or bowel cancer after their first colonoscopy examination and the value of additional colonoscopy follow-up examinations is unclear – to both the patient and the NHS services doing the colonoscopy examinations.

    Prof. Wendy Atkin also presented the results of the study to an audience of clinicians, gastroenterologists and research scientists at the Digestive Disease Week conference in Chicago, USA in May 2017.

    The results of the AA study will be analysed in 2018 and then published on the NIHR-HTA journal website and in peer reviewed medical journals.

    We anticipate that findings from this study will be used to inform current national and international guidelines, to make monitoring patients at risk of bowel cancer as safe and effective as possible and to make the best use of health service resources.