In the first trial of its kind, scientists followed 1,608 women with higher risk ductal carcinoma in situ (DCIS) from 136 participating centres in 11 countries.
The results, published in The Lancet, showed that following surgery, 803 women who received an additional boost of radiotherapy at the site where the tumour was removed from, had a reduced chance of the cancer coming back to the same place, compared to 805 women who didn’t.
But while more women who’d received the extra treatment stayed cancer-free five years afterwards (97.1% compared with 92.7% with no boost), they were more likely to experience side effects including breast pain and skin hardening.
The research was coordinated by the Breast International Group and included UK teams based at the University of Edinburgh, Western General Hospital, Edinburgh, the University of Sheffield, Weston Park Hospital, Sheffield and Royal Surrey County Hospital, Guildford.
Breast Cancer Now has awarded Professor Ian Kunkler and his team at the University of Edinburgh a new grant of £79,000, so they can continue to monitor the UK participants in the trial.
They will track whether cancer recurrence continues to be lower in the women who’d had the additional radiotherapy boost and the side effects they may experience.
Around 7,000 people in the UK are diagnosed with DCIS every year. DCIS is an early form of breast cancer when cancer cells have developed within the ducts of the breast, but remain within them and don’t have the ability to spread into the surrounding breast tissue or other parts of the body.
However, if left untreated, it’s estimated that up to half of DCIS cases will develop into invasive breast cancer.
When DCIS is limited to a small area, clinicians usually recommend breast-conserving surgery, removing only the small area of the breast affected.
This may be followed by a course of radiotherapy to the whole breast if there's a higher chance DCIS might return.
Professor Ian Kunkler, Consultant in Clinical Oncology at the Edinburgh Cancer Centre, University of Edinburgh, said:
“Boost radiation is regularly used to treat women with invasive breast cancer. But this is the first time we’ve been able to demonstrate that it’s an effective treatment for women with higher risk DCIS.
“We’re hugely encouraged by these results and the Breast Cancer Now grant will help us to understand the longer-term impact of the additional radiotherapy so that in the future, patients and clinicians can make an informed decision about whether it's right for them.”
Dr Kotryna Temcinaite, Breast Cancer Now’s Senior Research Communications Manager, said:
“It’s vital we develop smarter, more effective treatments for people with breast cancer. So, it’s incredibly encouraging that research we helped to fund has shown that thousands of women with higher risk DCIS could benefit from an extra dose of radiotherapy.
“Breast Cancer Now’s additional funding for this work will mean we can understand the role the radiotherapy boost can play in helping to reduce the risk of cancer returning over a longer period.
"It will also help establish which women will really benefit from the extra treatment, so that those who won’t, do not unnecessarily undergo additional radiotherapy which could impact their quality of life.”
ENDS
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