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

The Intermediate Adenoma (IA) study was started by the Cancer Screening and Prevention Research Group (CSPRG) in 2006 and funded by the National Institute for Health Research Health Technology Assessment Programme (NIHR-HTA) until 2013. The CSPRG was additionally supported by the Bobby Moore Fund for Cancer Research UK. The study was initiated to answer research questions that were identified by the Department of Health and Social Care as a priority area; namely, to assess the recommendations in the 2002 national post-polypectomy surveillance guidelines about how people with adenomas, or bowel polyps, should be monitored to protect them from bowel cancer in the future, focusing on those classified as being at intermediate risk, who accounted for the majority of surveillance colonoscopies.

In 2017, the CSPRG received additional funding from the NIHR-HTA to answer research questions in the same study population but on people classified as low- and high-risk as per the 2002 national surveillance guidelines, in addition to the intermediate-risk group previously investigated; this became known as the All Adenomas (AA) study. The results from the IA and AA studies played a key role in the development of the new 2020 UK post-polypectomy surveillance guidelines.

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

Our Data Protection and Privacy Notice

Privacy notice

This privacy notice explains your rights to your personal information, what you can expect us (the Cancer Screening and Prevention Research Group) to do with your personal data and our lawful basis for doing so. This notice also explains who you should contact if you have any queries or complaints about how we are processing your personal data.

Under the 2018 General Data Protection Regulation (GDPR) and accompanying Data Protection Act (2018) ‘personal data’ is any data that can be linked to an identifiable individual (for a full definition see: Information Commissioner’s Office (ICO) website: What is Personal Data?). Some types of personal data, such as health data, are additionally classified as ‘special category personal data’. The law considers special category personal data to be more sensitive and gives it more legal protection (for more information see: ICO website: Special Category Data). As the Cancer Screening and Prevention Research Group processes (processing is the term used to refer to collecting, analysing and storing data) health data, much of the personal data we hold is considered to be special category personal data.

Who is responsible for the lawful processing of your personal data?

The GDPR and Data Protection Act define roles and responsibilities for those involved in processing personal data.

The Cancer Screening and Prevention Research Group (hereafter; CSPRG) are a research group at Imperial College London. The CSPRG can be contacted via the ‘Contact Us’ page on this website. The data controller determines the purpose for which and the manner in which personal data is to be processed (see: ICO website: Controllers and Processors). For the personal data held by the CSPRG, the data controller is Imperial College London. The data controller’s representative for our data is the Director of Information Governance for Academic Health Sciences. All queries relating to the handling of personal data should be directed to the Imperial College London Data Protection Officer via email at dpo@imperial.ac.uk. Contact details can also be found at the end of this privacy notice.

Why are we processing personal data?

The research focus of the CSPRG is gastrointestinal cancers which includes bowel cancer, also known as colorectal cancer. In the UK, every year over 41,000 people are diagnosed with bowel cancer alone and 16,000 people die from this disease. Through our research we hope to reduce the number of people being diagnosed with gastrointestinal cancer and dying from this disease. Much of our work focuses on how to help make bowel cancer screening and surveillance programmes more effective and acceptable for patients, and more efficient for the NHS, and other health services internationally. To understand the effectiveness of bowel cancer screening and surveillance programmes, we conduct large scale studies on procedures conducted and the benefits to patients. Identifiable patient data are usually necessary to track long-term health outcomes for participants enrolled in our studies. The CSPRG therefore needs to collect and hold personal data – often special category personal data. Our more specific purposes for processing data for each of our studies are detailed on the ‘Studies’ pages of our website.

What personal data do we have?

The personal data we hold is special category personal data relating to individual health. For example, for several of our studies we analyse procedure and treatment information, information about cancers occurring, whether they progress and the patients’ long-term health outcomes. In addition, we also often require some basic information about patients such as age and gender to inform our analysis. The full details of the personal data processed for each of our studies can be found on the ‘Studies’ pages of our website.

To fulfil our research aims we obtain personal data from a variety of sources. Much of our data is either obtained directly from NHS Trusts, or via third parties such as NHS England, the Office for National Statistics, the Bowel Cancer Screening Programme, National Cancer Registries (including the Welsh Cancer Intelligence and Surveillance Unit) and Information Services Division Scotland, part of NHS National Services Scotland. More detailed explanations of our sources of data can be found on the ‘Patient Data’ page and ‘Studies’ pages of our website.

Where data has been obtained from third party data providers under section 251 approval, national data opt-outs have been applied by the provider since 2016.

How do we process personal data?

All personal data we hold are processed in secure systems. For each active study we have completed a Data Protection Impact Assessment that has been approved by the Head of the CSPRG (as the Information Asset Owner) and the Imperial College London Data Protection Officer. No processing performed by the CSPRG involves automated decision-making or profiling. Unless stated otherwise on the ‘Studies’ pages of our website, all personal data are processed by the CSPRG and certain third parties (see ‘Third-party processing’ below). None of our studies process or transfer personal data outside the UK.

The Imperial College Data retention schedule mandates that data is retained for ten years after the end of a study (see the College Retention Schedule here). The expected end of these ten year retention periods for each of our studies are listed under the ‘Studies’ pages of our website under the ‘How long will we retain the data?’ sections.

Third-party processing

For the purposes referred to in this privacy notice and relying on the bases for processing as set out above, we may share your personal data with certain third parties:

Other College employees, agents, contractors and service providers (for example, suppliers of printing and mailing services, email communication services or web services, or suppliers who help us carry out any of the activities described above). Our third-party service providers are required to enter into data processing agreements with us. We only permit them to process your personal data for specified purposes and in accordance with our policies.

What is our lawful basis for processing personal data?

Processing personal data requires justification under two legal frameworks: the GDPR/Data Protection Act 2018 and under the common law duty of confidentiality.

Article 6 of the GDPR lays out six valid bases under which personal data can be processed lawfully. We process personal data under lawful basis 6(1)(e) ‘Public task’ as: processing is necessary for the performance of a task carried out in the public interest. We are also required to have a separate lawful basis for processing the more sensitive special category personal data. Our legal basis for processing special category personal data is Article 9(2)(j) ‘processing is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes […]’

In addition, health data (such as that the CSPRG hold) require a separate lawful basis under the common law duty of confidentiality. In some of our studies, patients consented to be part of the study and for the CSPRG to process their data. In other studies, consent could not be sought due to practical considerations or the nature of the study. In these studies, we have obtained lawful permission to obtain and process personal data under section 251 of the National Health Act 2006. The common law legal bases for data processing in each study are explained in the ‘Studies’ pages of our website under the ‘What approvals has the study received?’ sections.

What are your rights concerning your personal data?

The GDPR grants individuals several rights concerning their personal data:

The right to object (to processing of the data)
The right to correct (inaccurate or incomplete data)
The right to erasure (also known as “the right to be forgotten”)
The right to restrict processing (e.g. while the accuracy of the data is contested)
The right to portability (to have a copy of any data you have provided to us)
The right to access (to have a copy of data we hold about you)
The right to withdraw consent (if you have previously consented to take part)

If you think that we might be processing your data and you wish to exercise any of the rights listed above, please get in touch using the details on the Contact Us page or by contacting the Imperial College London Data Protection Officer via email at dpo@imperial.ac.uk. Though it may not always be possible for us to fulfil your request, we will respond to your query within one month. For more information on your GDPR rights, please see guidance provided by the Information Commissioner’s Office.

Where can you direct queries or complaints?

Please be aware that individuals also have a right to complain to a supervisory authority- in this case the Information Commissioner’s Office (ICO) – if they feel their data is being used unlawfully. The ICO does recommend that you seek to resolve matters with the data controller – for our data that is Imperial College London – before contacting the Commissioner’s Office. If you wish to raise a complaint on how we have handled your personal data or if you want to find out more about how we use your data, please contact Imperial College London’s Data Protection Officer via email at dpo@imperial.ac.uk, via telephone on 020 7594 3502 or via post at Data Protection Officer, Faculty Building Level 4, Imperial College London, London SW7 2AZ.

If you are not satisfied with our response or believe we are processing your personal data in a way that is not lawful you can raise your complaint with the Information Commissioner’s Office. The ICO’s address is: Information Commissioner’s Office, Wycliffe House, Water Lane, Wilmslow, Cheshire SK9 5AF; Helpline number: 0303 123 1113; ICO website: https://www.ico.org.uk.

Privacy and data protection information relating specifically to the Intermediate Adenomas and All Adenomas studies

The CSPRG at Imperial College London processes special category personal data for the IA and AA studies. The purpose of these studies is to examine the UK surveillance guidelines. To do this, we are monitoring the long-term outcomes of patients classified at low-, intermediate- and high-risk of bowel cancer after removal of adenomas. A patient’s surveillance regime is based on their risk classification. Long-term special category personal data are needed to assess the clinical efficacy and cost-effectiveness in the different risk categories. This information was used to generate evidence to support an update of the UK surveillance guidelines and to investigate the potential cost implications of the updated guidelines for the NHS (see ‘What are the aims of the IA and AA studies?’ below). The special category personal data used in this study is crucial to the success of this project and thereby the beneficial impact on patients and the NHS.

Imperial College London (the data controller for data processed by the CSPRG, see above) are the recipient of data for the IA and AA studies. The special category personal data for the IA and AA studies is received by the CSPRG from several sources, given below.

1. Hospital trusts in England and Scotland

The CSPRG received clinical data – such as the results of endoscopies – from 17 participating hospitals in England and Scotland. The 17 participating hospitals were:

2. NHS Digital

NHS Digital collect and process data from across the health and social care system in England. For patients in England, we received cancer incidence and mortality data from NHS Digital. NHS Digital also received cause of death data for patients in England from the Office for National Statistics which were passed on to the CSPRG.

3. The Office for National Statistics

The Office for National Statistics provided cause of death data for patients in England to the CSPRG via NHS Digital.

4. Public Health England

Cancer staging data for patients in England were provided to the CSPRG by Public Health England.

5. NHS National Services Scotland

For patients in Scotland, cancer incidence and mortality data, cause of death data and cancer staging data were provided to the CSPRG by NHS National Services Scotland.

6. NHS Central Register

For patients from England who moved to Scotland during the course of the study, cancer staging data were provided to the CSPRG by the NHS Central Register.

All data we receive from these data providers is pseudonymised. Pseudonymised data (see also GDPR Article 4.3) are personal data that can no longer be attributed to a specific individual without additional information because easily identifiable identifiers – such as names and NHS numbers – have been removed from the data before it is received by the CSPRG. This means that we cannot link the data we receive to other personal or special category personal data.

A subset of the AA study data was sent to our collaborators at the Health Economics Research Centre at the University of Oxford, so that they could conduct a health economics analysis. Imperial College London remains the data owner of this data subset and the University of Oxford acted as a Data Processor. The University of Oxford have completed the health economics analysis and deleted their copies of the data. This data processing was covered by a data sharing agreement between Imperial College London and the University of Oxford.

What are the aims of the IA and AA studies?

The 2002 UK guidelines for the surveillance of people found to have bowel polyps classified people into those at low-, intermediate- or high- risk of developing bowel cancer in the future. The guidelines were developed in 2002 by Professor Atkin (former head of the 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, and world leader in colonoscopy. In 2011, these guidelines were adopted by NICE (the National Institute of Clinical Excellence).

The guidelines needed to be re-examined as they had not been updated since development in 2002. We initially focussed on people classified as intermediate risk on the basis of their bowel polyps, who were recommended to have three yearly surveillance colonoscopy. We hypothesised that this was likely an appropriate regime for some people in the intermediate-risk group, but that it may not be the best option for others. For example, there might be a group of people within the intermediate-risk group for whom surveillance colonoscopy is unnecessary or could be performed at an interval greater than three years. Therefore, the aim of the IA study was to provide robust evidence to underpin revisions of the 2002 national surveillance guidelines in order to improve how we monitor people in the intermediate-risk group. We also aimed to examine the psychological impact of having surveillance on patients and costs of surveillance to the NHS.

The AA study extended these analyses, including an examination of the appropriateness of the 2002 national surveillance guideline recommendations for people in the low-risk and high-risk groups, to provide further evidence to support an update of these guidelines. We also aimed to investigate the cost-effectiveness of surveillance for each risk group.

What type of studies are the IA and AA studies?

The IA and AA studies are observational, retrospective cohort studies utilising routinely collected data on health examinations performed in the past.

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

The majority of cancers in the bowel develop from adenomas or polyps, which are growths on the inner surface of the bowel. Bowel polyps are common, especially in older people, and usually do not develop into cancer; however, as they have the potential to become cancerous, they are usually 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 test in a bowel cancer screening programme that has indicated the presence of blood in the stool. A colonoscopy examination involves a flexible tube with a camera attached to one end being inserted into the rectum to examine the inside of the bowel.

Surveillance guidelines classify people into risk groups based on the characteristics of polyps found during colonoscopy. In the 2002 UK surveillance guidelines, people with 1 or 2 small (<10mm) polyps were classified into the low-risk group and this group were generally deemed to not require a follow-up or ‘surveillance’ colonoscopy.

People with 3 to 4 small polyps or 1 to 2 polyps, of which at least one is large (≥10mm), were classified into the intermediate-risk group and recommended a surveillance colonoscopy after three years. People with 5 or more small polyps or 3 or more polyps, of which at least one is large, were classified as high-risk and recommended a surveillance colonoscopy after one year and then again every three years.

Surveillance colonoscopy carries a small but real risk of serious complications for patients and is demanding on NHS resources. It is therefore essential that surveillance colonoscopies are directed towards people who need and benefit from surveillance the most.

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

We have collected information from hospitals and national databases in the UK for the purposes of the IA and AA studies.

We collected endoscopy and pathology data from 17 hospitals in the UK (details listed below) on approximately 250,000 men and women who underwent bowel examinations between 1972 and 2010, of whom approximately 30,000 were found to have bowel polyps. We obtained follow-up data on cancers and deaths from the National Health Service (NHS) Central Register, NHS Digital, and the NHS National Services Scotland.

The hospital data are 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 CSPRG, except for dates of birth for the purpose of ensuring data integrity so that we can validate or query discrepancies in the follow-up data that we receive for these patients from the national 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. 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 period for which we collected data on patients procedures from the hospitals. Therefore, we obtained an update on the procedures that occurred during the time period not covered by the original data collection.

The 17 UK hospitals where data were collected from are listed below, together with an approximate range for the dates of data collection:

Royal Sussex County Hospital, Brighton and Sussex University Hospitals NHS Trust, May 2001 to April 2008
St Mark’s Hospital, London North West Healthcare NHS Trust, January 1972 to July 2007
Glasgow Royal Infirmary, Greater Glasgow and Clyde NHS Trust, April 1996 to August 2009
Charing Cross Hospital and Hammersmith Hospital, Imperial College Healthcare NHS Trust, October 1997 to November 2007
St Mary’s Hospital, Imperial College Healthcare NHS Trust, January 1985 to July 2010
Cumberland Infirmary, North Cumbria Acute Hospitals Trust, October 1998 to September 2009
Queen Elizabeth Hospital, Queen Elizabeth Hospital NHS Trust, October 1999 to May 2006
Queen Mary’s Hospital, Queen Mary’s Sidcup NHS Trust, October 1988 to July 2009
Royal Liverpool University Hospital, Royal Liverpool and Broadgreen University Hospitals Trust, January 2000 to September 2009
Royal Surrey County Hospital, Royal Surrey County Hospital NHS Trust, September 1997 to May 2010
New Cross Hospital, Royal Wolverhampton Hospitals NHS Trust, January 1993 to November 2007
Royal Shrewsbury Hospital, Shrewsbury and Telford Hospitals NHS Trust, December 2001 to September 2009
Torbay District General Hospital, South Devon Healthcare NHS Foundation Trust, October 2000 to August 2007
St George’s Hospital, St George’s Healthcare NHS Trust, February 1992 to July 2009
University Hospital of North Tees, University Hospital of North Tees Trust, June 1986 to December 2006
Leicester General Hospital, University Hospitals of Leicester NHS Trust, April 1998 to March 2008
Yeovil District Hospital, Yeovil District Hospital Foundation Trust, February 1997 to May 2008

In addition, we collected information on the stage at diagnosis of the bowel cancers from Public Health England for the health economics analysis performed by our collaborators at the University of Oxford.

What approvals has this study received?

The IA and AA studies use historical data collected for a very large group of patients (over 250,000) 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, as listed below:

Royal Free Research Ethics Committee (REC) approval
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 received approval from:

London – Hampstead Research Ethics Committee (previously Royal Free REC)
NHS Health Research Authority, including section 251 approval
In 2018, we received further approval from NHS Digital and NHS Scotland.

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

How long will we retain the data?

We have funding to continue data analysis until 2028. 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 2038.

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

The IA study showed that most intermediate-risk patients derive benefit from having a surveillance colonoscopy. However, approximately 25% of the intermediate-risk group were already at low risk of developing bowel cancer after their polyps had been removed, before any surveillance, indicating that surveillance might not be warranted for this ‘lower-risk’ subgroup.

These findings were published in The Lancet Oncology and the NIHR-HTA Journal in 2017. Professor Atkin also presented the findings to an audience of clinicians, gastroenterologists and research scientists at the Digestive Disease Week conference in Chicago, USA, in 2017.

The AA study demonstrated that patients classified into the low-risk group are very unlikely to develop bowel cancer after their polyps have been removed and so do not need any surveillance. Our updated analyses of the intermediate-risk group corroborated our finding from the IA study that a ‘lower-risk’ subgroup of intermediate-risk patients exists that could be withdrawn from surveillance. Finally, we showed that surveillance is necessary for high-risk patients who remained at increased risk of bowel cancer after polyp removal. These findings were published in the journal Gut in 2020 and in the NIHR-Health Technology Assessment (HTA) Journals Library.

Together, our findings demonstrated that many patients with polyps do not require the level of surveillance recommended in the 2002 UK surveillance guidelines. The findings were fed into the development process of the new 2020 UK post-polypectomy surveillance guidelines, also published in Gut in 2020 and endorsed by the British Society of Gastroenterology, the Association of Coloproctology of Great Britain and Ireland, and Public Health England. We were also able to examine whether the three-year interval for surveillance was appropriate for those needing surveillance.

The updated post-polypectomy surveillance guidelines are helping to optimise the use of NHS resources, ensuring patients at high risk of bowel cancer receive surveillance and are protected, while minimising exposure of low-risk patients to unnecessary invasive procedures. In this way, our research is and will continue to bring great benefit to both patients and the NHS.