PARABLE

  • Research type

    Research Study

  • Full title

    PARABLE: Proton beam therapy in patients with breast cancer: evaluating early and late effects

  • IRAS ID

    302709

  • Contact name

    Charlotte Coles

  • Contact email

    cec50@medschl.cam.ac.uk

  • Sponsor organisation

    The Institute of Cancer Research

  • ISRCTN Number

    ISRCTN14220944

  • Duration of Study in the UK

    8 years, 0 months, 1 days

  • Research summary

    Around 33,000 breast cancer patients/year need radiotherapy (RT) as part of their treatment. A small proportion (around 500/year) are not well served by current RT due to the position of their lymph nodes near the breast bone and/or body-shape. This can result in less RT dose where needed and/or unwanted dose to healthy tissue such as the heart, reducing chance of cure and increase risk of serious heart damage many years later. Proton Beam Therapy (PBT) is different from RT as it delivers dose to a defined depth thereby giving better dose coverage where needed with less dose to the heart. Increased skin and rib side effects around 2 years after treatment have however been reported, although this is mostly with older PBT techniques. The NHS now has 2 PBT centres, providing a unique opportunity to compare PBT with RT for this relatively small but important patient group with unmet need.

    192 patients with breast cancer who have at least a 2 in 100 predicted lifetime risk of serious heart side effects from their planned RT will receive either PBT or RT. The choice of PBT or RT will be decided randomly by computer to minimise bias. We will assess the average heart dose received with PBT compared with RT as a validated early measure predicting late heart RT damage. Patient-reported side effects in the treated breast will be compared between PBT and RT at 2 years. Outcomes and side effects will be collected up to 5 years and we will use NHS databases for longer term effects. We will assess acceptability of randomisation to PBT v RT and any inequality of access.

    Results will be presented at international conferences and published in peer reviewed medical journals; with PPI partners we will produce lay summaries

  • REC name

    West of Scotland REC 3

  • REC reference

    21/WS/0171

  • Date of REC Opinion

    25 Jan 2022

  • REC opinion

    Further Information Favourable Opinion