Since 2020, it is estimated that tens of thousands of people in the UK have already benefited from a shorter radiotherapy course on the NHS.
One week of radiotherapy is just as effective as a traditional three-week course for many people with early-stage breast cancer, researchers say.
New 10-year results from a clinical trial show the same level of cancer control in people having radiotherapy for just five sessions, with the chances of the cancer coming back at under 4%.
The shorter schedule also reduces hospital visits and eases pressure on radiotherapy services, experts said.
The Fast-Forward trial, sponsored by the Institute of Cancer Research (ICR), London and published in the Lancet Oncology, followed more than 4,000 patients for a decade after their treatment.
Researchers 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.
All those in the study were people whose cancer had not spread and who had had surgery to remove it. It included people with different subtypes of breast cancer.
After 10 years, the risk of cancer coming back in the treated breast was very low in all three groups.
It was 3.6% for the standard three-week treatment, 2.9% with the one-week treatment with a slightly higher dose and 2.1% 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, making it an ideal option.
The findings build on previous five-year results that have already led to a change in clinical practice.
Since 2020, the ICR estimates tens of thousands of people in the UK have already benefited from a shorter radiotherapy course on the NHS.
Professor Murray Brunt, chief investigator of the 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, from the ICR, who co-led the trial, said: “These final 10-year results mark a significant milestone in breast cancer treatment and reinforce the growing shift towards more efficient radiotherapy approaches.”
Each year, around 37,000 people in the UK receive radiotherapy for breast cancer.
Karen Davis, 58, from Newcastle-under-Lyme in Staffordshire, took part in the trial.
“When the consultant told me I had cancer I thought that was it – I was 45 and thought I was going to die,” she said.
“I was so relieved when I found out it was treatable, but still very concerned.
“As well as the radiotherapy I had a lumpectomy and an oophorectomy, which is removal of the fallopian tubes and ovaries. Then I was on tamoxifen tablets for 10 years.
“I wanted to help other ladies in the future by going on the trial. I knew that in years gone past, my treatment would have been a full mastectomy – and that my treatment had improved because of trials and research.
“I was slightly nervous when I started the trial. I had the three weeks of radiotherapy in five days instead.
“I’ve been in remission ever since and the only reminder of my treatment is a bit of numbness where I had the radiation.
“Before I was diagnosed, I was a professional hairdresser wig and hair extension specialist. After my diagnosis I did advanced training in wigs, bespoke hair pieces and hair in recovery hair extensions.
“Now when I’m fitting wigs for ladies who have breast cancer, if they’re upset, I can tell them I had breast cancer and I know what they’re going through. It can give them hope.
“Sometimes they tell me they’re having five days of radiotherapy and I say, ‘Oh I did the trial for that’.
“And they can see how well I am. I’m so pleased I took part, and I’ve been able to help these ladies that I come across in my daily work.”
Dr Simon Vincent, chief scientific officer at Breast Cancer Now, said the 10-year findings “add to the strong evidence supporting a shorter course of radiotherapy, which is already recommended for many people with early-stage breast cancer and is being used across the NHS”.
He said: “Reducing the length of treatment, number of appointments and time spent in hospital has a positive impact for people affected by breast cancer, helping to make the difficult period following their diagnosis more manageable and offering a significant boost to their quality of life. It also eases pressures on an already overstretched health service.”
