One‑week radiotherapy course safe and effective in the long term for early‑stage breast cancer

Research led by a Keele University oncologist has found that a one-week course of post-surgery radiotherapy is just as safe and effective as the traditional three-week course for people with early-stage breast cancer. 

The FAST-Forward trial, led by Keele’s Professor Murray Brunt and sponsored by The Institute of Cancer Research, London, followed more than 4,000 patients for a decade after their treatment.  

The 10-year results of this phase III randomised trial, funded by the National Institute for Health and Care Research (NIHR) and published in the Lancet Oncology, show that a shorter, five-day radiotherapy schedule provides the same level of cancer control as the traditional three-week treatment.  

These findings build on previous five-year results that have already driven a shift in clinical practice. Since 2020, it is estimated that tens of thousands of people in the UK have already benefited from the shorter course on the NHS. Researchers expect this approach will also reduce the burden on people undergoing treatment for breast cancer worldwide and expand access to life-saving radiotherapy.  

Breast cancer is one of the most common cancers globally, and radiotherapy plays a critical role in reducing the risk of recurrence after surgery. Each year, around 37,000 people in the UK receive radiotherapy for breast cancer.  

A shorter treatment course is not only more convenient for patients—it also reduces hospital visits and eases pressure on radiotherapy services, making treatment more accessible.  

The research team compared the traditional schedule of 15 treatments over three weeks with two shorter schedules that used five treatments over one week. The two shorter courses gave slightly different amounts of radiation to allow the research team to work out the best dose.   

After 10 years, cancer coming back in the treated breast was very low in all three groups: 3.6 per cent for the standard three-week treatment, 2.9 per cent with the one-week treatment with a slightly higher dose, 2.1 per cent with the one-week treatment with a slightly lower dose.   

The lower dose one-week treatment had side effects that were very similar to the standard approach, with no increase in long-term breast or chest wall changes. Because of this, this dose and schedule are now the recommended option.  

Professor Murray Brunt, chief investigator of the FAST-Forward study and Professor of Clinical Oncology at Keele University, said: “These 10-year results provide definitive long-term evidence that one-week radiotherapy given at an appropriate dose to the breast is a safe, effective, and more practical option for people with breast cancer. 

“By reducing treatment from 15 sessions to just five, we can offer patients the same excellent cancer control with fewer hospital visits, less disruption to their daily life, and reduced pressure on healthcare services. This approach has already transformed practice in the UK and has the potential to improve access to life-saving treatment for people with cancer worldwide. 

“Hearing patients talk about how much it helps to only need one week of radiotherapy has been really encouraging for everyone involved.”  

Professor Judith Bliss, Professor of Clinical Trials at The Institute of Cancer Research, London, who co-led the trial, said: “The FAST-Forward trial is transforming cancer treatment by reducing standard breast radiotherapy from 3 weeks to just one week, without compromising effectiveness.  

“The streamlined schedule has made radiotherapy more accessible, particularly for people who find it difficult to attend hospital and those in lower-income countries.”  

“The FAST-Forward trial is part of a long-term programme of research into improving breast cancer radiotherapy at The Institute of Cancer Research (ICR).  

“These final 10-year results mark a significant milestone in breast cancer treatment and reinforce the growing shift toward more efficient radiotherapy approaches. The success of FAST-Forward has led to the ongoing NIHR-funded FAST-Forward Boost trial, which is investigating whether more extensive radiotherapy—including an additional “boost” dose for some patients—can also safely be delivered in five days.  

Professor Anthony Gordon, Director for NIHR's Health Technology Assessment (HTA) Programme, added: “The legacy of the FAST-Forward trial is clear to see, with thousands of women benefiting from shorter courses of radiotherapy and fewer hospital visits, helping the health and care sector to achieve more effective and efficient use of resources. The new 10-year results show the benefit of investing in high-quality, long-term research to improve the health and wealth of the nation.  

“NIHR's research aims to tackle the most urgent health and social care challenges, targeting the areas of greatest need and where the most significant impact can be made. The findings from the FAST-Forward trial have already made a considerable difference to the treatment regimens that breast cancer patients undergo, making them more efficient, while at the same time, easing pressure on NHS services."

Patient story

Karen Davis, Newcastle-under-Lyme

Karen Davis lives with her husband David and Jack Russell Nathanial in Newcastle-under-Lyme in Staffordshire.

“My oncologist, Professor Murray Brunt, told me about the FAST-Forward trial before I’d had any treatment. I’d just been diagnosed with stage two hormone receptor positive breast cancer.

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