Researchers have found that an extra radiotherapy boost could reduce the risk of higher risk DCIS coming back in the same breast.

Scientist looking at a sample

Researchers, part-funded by Breast Cancer Now, have found that an extra radiotherapy boost could reduce the chances of higher risk DCIS coming back in the same breast.

However, the study also found that whilst women were more likely to remain cancer-free five years after receiving the extra treatment, they were more likely to experience side effects such as breast pain and skin hardening.

Breast Cancer Now has now awarded the researchers a new grant so that the group can continue to monitor participants in the trial to understand the long-term impact of the additional treatment.

Improving treatment for DCIS

In the UK, around 7,000 people are diagnosed with ductal carcinoma in situ (DCIS) every year. It‘s an early form of breast cancer where cancer cells have developed in the ducts of the breast but have not spread to the surrounding tissue or other parts of the body. It’s estimated that, if left untreated, half of DCIS cases will develop into invasive breast cancer.

When DCIS is only in a small area, doctors usually recommend breast-conserving surgery, where only a small, affected area of the breast is removed. This can sometimes be followed by a course of radiotherapy if there is a higher chance the DCIS may return.

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. The researchers investigated whether an additional boost of radiotherapy could help to further prevent DCIS from returning in the same area.

An extra radiotherapy boost

Researchers followed 1,608 women with higher risk DCIS from 136 participant centres in 11 countries to assess how effective the extra dose was at preventing it from coming back.

They found that 803 women who received the additional boost of radiotherapy after surgery had a reduced chance of the cancer coming back to the same place, compared to 805 women who didn’t. 97.1% of women who received the extra treatment remained cancer-free five years afterwards, compared to the 92.7% who did not receive the boost.

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.’

However, the women who received the additional boost of radiotherapy were also more likely to experience side effects such as breast pain and skin hardening.

Understanding the long-term impact

Now, Breast Cancer Now has awarded Professor Ian Kunkler and his team at the University of Edinburgh a new grant of £79,000 to continue their work.

This is so they can continue to monitor the UK participants in the trial and track whether cancer recurrence continues to be lower in the women who received the extra boost as well as better understand some of the side effects that they may experience.

Dr Kotryna Temcinaite, Breast Cancer Now’s Senior Research Communications Manager, added: ‘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 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, don’t unnecessarily undergo additional radiotherapy which could impact their quality of life.’

The research was published in the The Lancet and was funded by Breast Cancer Now, the National Health and Medical Research Council of Australia, Susan G Komen for the Cure, OncoSuisse, Dutch Cancer Society, and Canadian Cancer Trials Group.