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

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 bowel cancer, also known as colorectal cancer. In the UK, every year over 41,000 people are diagnosed with bowel cancer and 16,000 people die from this disease. Through our research we hope to reduce the number of people being diagnosed with bowel 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 from 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 Digital, 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 exclusively by the CSPRG.  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.

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(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(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.

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 adenoma surveillance guidelines. To do this, we are monitoring the long-term outcomes of patients classified at low-, intermediate- and high-risk of colorectal cancer after endoscopy. A patient’s surveillance regime is based on their risk classification. Long-term special category personal data are needed to assess the efficacy, cost-effectiveness and outcomes of surveillance regimes in the different risk categories. This information will be used to generate evidence to support an update of the adenoma surveillance guidelines and to investigate the potential cost implications to 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 the public good generally.

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

1. Hospital trusts in England and Scotland

The CSPRG receive 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 receive cancer incidence and mortality data from NHS Digital. NHS Digital also receive cause of death data for patients in England from the Office for National Statistics which is passed on to the CSPRG.

3. The Office for National Statistics

The Office for National Statistics provide 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 are 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 are provided to the CSPRG by NHS National Services Scotland.

6. NHS Central Register

For patients from England who move to Scotland during the course of the study, cancer staging data are 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 the CSPRG cannot link the data we have received to other personal or special category personal data.

A subset of the AA study data has been sent to our collaborators at the Health Economics Research Centre at the University of Oxford, so that they can conduct a health economics analysis. Imperial College remain the data owners of this data subset and the University of Oxford act as Data Processors. At the end of their part in the study, the University of Oxford will delete their copies of the data. This data processing is covered by Data Sharing Agreements between Imperial College London and the University of Oxford.

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. Below are details of where and for which periods of time we have collected this information, or links to where this information can be found.

UK hospitals

17 hospitals in the UK (see 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.

The 17 UK hospitals where data was collected from and approximate date range of data collected:

  • 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

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.

NHS Bowel Cancer Screening Programme

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.

Kaiser Permanente

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
  • 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?

As the IA study has recently been amended to include the AA study objectives, the study duration has been extended. We have funding to continue data analysis until 2022. 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 2032.

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 are currently being analysed. After the analysis is complete the results will be 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.