RecruitingObservational

IBIS-II-O: Observational long-term follow up study of participants from the IBIS-II DCIS and Prevention clinical trials of drugs for breast cancer prevention

The IBIS-II-O study is an observational follow-up project looking at the long-term health of over 3,000 UK women. These women previously joined the IBIS-II clinical trials, which tested whether a medicine called anastrozole could help prevent breast cancer in women at higher risk. Those earlier studies showed that anastrozole significantly reduces breast cancer risk, with protection continuing for years after stopping treatment. Now, researchers at Queen Mary University of London are studying how these women are doing over a much longer period, running up to 2031. Because this study only reviews existing electronic health records through NHS England, participants do not need to take any new medicines, visit hospitals, or undergo extra tests. The study simply tracks records to see if cancer returns, whether new conditions develop, and to monitor any lasting effects. No new volunteers can join, as it only follows women from the original trials.

At a glance

Status

Recruiting

Sponsor

Queen Mary University of London

Enrolment target

3,000

Start

01 Jun 2021

Estimated completion

01 Jun 2031

Breast cancer prevention

What is this study about?

Breast cancer is the most common cancer in the UK, but treatments and prevention methods have improved greatly over the years. Between 2004 and 2021, thousands of women at an increased risk of breast cancer took part in the groundbreaking IBIS-II clinical trials. In these studies, women took a daily medicine called anastrozole, comparing it either to another drug named tamoxifen or to a dummy pill (placebo) for five years. The results brought encouraging news: anastrozole significantly lowered the chances of breast cancer developing, and this protective effect lasted long after the women stopped taking the medicine.

The IBIS-II-O study is the next chapter in this vital research. Scientists want to understand how long this protective shield lasts and what happens to women's health decades down the road. To do this, researchers at Queen Mary University of London are tracking the medical journeys of more than 3,000 UK women who completed the earlier IBIS-II trials.

Instead of asking women to travel to hospitals or fill out questionnaires, this study works quietly in the background. It uses secure, routine NHS health records to look for any new cancer diagnoses, other medical conditions, or long-term side effects. By learning from these real-world health records up until 2031, researchers hope to discover how best to protect future generations of women from breast cancer.

Key takeaways

Follows the long-term health of over 3,000 UK women from previous IBIS-II trials.
Investigates the long-lasting protective effects of the drug anastrozole against breast cancer.
Uses secure NHS electronic records with no extra hospital visits, tests, or treatments needed.
The study runs until June 2031 to collect over a decade of valuable safety and health data.
Closed to new volunteers, as it only tracks women from the original research group.

Who may be eligible?

This study is only open to women who were already enrolled and received treatment in the original IBIS-II Prevention or IBIS-II DCIS trials. Because this is a long-term follow-up of an existing group of patients, it is not accepting any new volunteers. If you did not take part in those specific earlier trials, you cannot join.

To be included in this follow-up, a woman must have been alive when the original study closed and have agreed to let researchers access her health records. Her original local hospital trial site must also have completed its work on the earlier trial protocols.

Women are not included in this tracking if they have sadly passed away, have moved abroad, or have chosen to withdraw their consent for their NHS records to be shared with the research team.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

You were randomly assigned to a treatment group in the original IBIS-II Prevention or IBIS-II DCIS trials.
You gave consent for your NHS health records to be followed over time.
You have not previously withdrawn your consent from the IBIS-II research project.
You currently reside in the UK and are registered with the NHS.

Answer every question to see your result.

What does participation involve?

Taking part in this study is completely passive, meaning participants do not need to do anything new. There are no clinic appointments to attend, no travel requirements, no blood tests or scans, and no study medicines to take. Instead, researchers securely link participants' trial details to NHS electronic health databases in England. The study team simply monitors these records for any new cancer diagnoses, hospital visits, or long-term health outcomes. This tracking began in July 2018 and is planned to continue until June 2031, giving researchers around 13 years of valuable long-term data.

Potential risks and benefits

Because this study only reviews existing electronic health records, there are no physical side effects, medical risks, or lifestyle burdens for participants. There is no direct personal medical benefit, such as receiving a new drug, but the information gathered will help doctors better understand cancer prevention for future generations. All personal health data is handled with strict confidentiality under UK data protection laws. Any participant has the right to withdraw their consent at any time, meaning their NHS records will no longer be checked, and doing so will not affect their regular healthcare in any way.

Locations (1)

Queen Mary University of London
Approximate
London, England

Common questions

Can I volunteer to join this study?

No. The study is only open to women who previously took part in the original IBIS-II Prevention or IBIS-II DCIS trials. It is not recruiting any new participants.

Do I need to take any medication or visit a clinic?

No. Taking part does not involve any pills, appointments, or medical tests. Researchers only review routine NHS health data in the background.

How long will the study run for?

The study began tracking health records in July 2018 and is expected to continue until June 2031.

How is my personal medical information kept safe?

All health records are handled securely following strict NHS and UK data protection rules. Your information is kept confidential and is only used for approved health research.

What if I took part in IBIS-II but no longer want my records tracked?

You are completely free to change your mind at any point. You can withdraw your consent by contacting the study team, and your records will stop being reviewed without affecting your ordinary NHS care.

How to find out more

Barts Clinical Trials Unit

bartsctu@qmul.ac.uk +44 (0)2078823517 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.