PARABLE

PARABLE investigates a new type of radiotherapy to see if it can help people with breast cancer avoid side effects of treatment.

Disease site: Breast cancer

Status: Enrolling participants

Trial documents (password protected)

What is the study about? 

PARABLE investigates a new type of radiotherapy to see if it can help people with breast cancer avoid side effects of treatment.

Traditional radiotherapy uses a beam of x-rays to target and kill cancer. Proton beam therapy uses a stream of proton particles, instead of x-rays. Protons can be targeted even more precisely than traditional radiotherapy. 

The location of some people’s breast cancer means that the heart can be exposed to higher doses of x-rays using traditional radiotherapy methods. This can lead to heart problems in later life. PARABLE is investigating whether proton beam therapy reduces the dose of radiotherapy the heart receives and whether the breast short-term side effects experienced by participants are similar to traditional radiotherapy.

Proton beam therapy is currently only available at two NHS hospitals in the UK, in Manchester and London. Results of PARABLE will be used to see if proton beam therapy would be helpful for people with breast cancer near their heart in the future.

Who is included in the study? 

One-hundred and ninety-two people diagnosed with breast cancer which has been removed by surgery will join PARABLE. Everyone who joins PARABLE will have a slightly higher risk of developing heart problems after radiotherapy, due to the position of their cancer, age and risk factors that are already present, such as pre-existing heart disease. People will be invited to join by their medical teams at around 20 NHS hospitals across the UK.

What are the study treatments? 

Everyone who joins PARABLE will already have had surgery to remove their breast cancer. After joining the trial they will be put into one of these two treatment groups:

  • Standard radiotherapy, targeted at the area the cancer was removed from
  • Proton beam therapy, targeted at the area the cancer was removed from

Both groups will have treatment every weekday for 3 weeks. People in the standard radiotherapy group will have treatment at their local hospital, however people in the proton beam therapy group will need to travel to one of the two UK proton beam centres, in London and Manchester. People travelling to the proton beam therapy centres will be provided with accommodation by the NHS during their treatment and reimbursement of travel expenses will also be available.

Participants have regular check ups during and after their treatment and we collect information about how they are getting on until the study is completed.

Further information for participants  

Patient Information Sheet (intro)

Patient Information Sheet (main)

A PARABLE Participant's Experience

A detailed summary is available on Cancer Research UK’s website

Trial documents (password protected)

Further information for healthcare professionals 

Protocol

Contact details and regulatory information 

Chief Investigator: Professor Charlotte Coles, University of Cambridge

ICR-CTSU scientific lead: Professor Judith Bliss

Technical RT and Mechanistic Lead: Dr Anna Kirby, The Royal Marsden

Methodology Lead: Jo Haviland, Queen Mary University

Trial management contact: [email protected]

Sponsor: The Institute of Cancer Research

Funding: National Institute for Health Research (NIHR) – Efficacy and Mechanism Evaluation (EME) Programme (NIHR131120)

Additional Financial Support (Patient Travel): Breast Cancer Now

Trial identifiers 

REC reference: 21/WS/0171

CPMS ID: 52070

ISRCTN: ISRCTN14220944

Publications and presentations 

A.M. Kirby, F. Holt, C.W. Taylor, J.S. Haviland, M. MacKenzie, C.E. Coles, Should patients requiring radiotherapy for breast cancer be treated with proton beam therapy? BMJ, June 2023

A.M. Kirby, J.S. Haviland, M. Mackenzie, H. Fleming, C. Anandadas, S. Wickers, E. Miles, N. Isles, J.M. Bliss, C.E. Coles, The PARABLE Trial Management Group, Proton Beam Therapy in Breast Cancer Patients: The UK PARABLE Trial is Recruiting, Clinical Oncology, June 2023