A study presented last Sunday at an oncology conference in Barcelona opens the way to “reducing the treatment burden” for breast cancer patients, as it discusses the possibility of shortening the duration of radiation therapy from 5 weeks to only 3.
Organizers of the annual conference of the European Society for Medical Oncology, which continued until Tuesday in the Spanish city, expect the results of this study to soon lead to a change in the way breast cancer is treated.
In this phase III study, researchers evaluated 1,265 patients over 5 years, comparing the effects of standard 5-week radiation therapy with a new, shorter, 3-week treatment.
All of the women in the study had breast cancer that had spread to the lymph nodes, meaning their tumor was no longer localized.
Some patients received slightly higher doses per session, but overall they were scheduled for fewer sessions.
“Previous studies had shown that shorter radiotherapy was as effective for localised tumours, but for women whose tumours had spread to the lymph nodes, there was no evidence that shorter sessions could be effective,” explained Sophia Rivera, an oncologist and radiotherapist at the Gustave Roussy Institute in France, who presented the research results.
To shorten the sessions to 3 weeks, the radiation dose was increased slightly each time.
“When treating the breast and lymph nodes as well, you are targeting much larger volumes, including healthy tissues like the lung, heart or esophagus,” Sofia Rivera told AFP. So when the dose was higher, it was feared that it would lead to more side effects associated with the treatment.
Gain in quality of life
However, the results of the study dispelled this fear, as the treatment with the smallest number of fractions led to an increase in “the overall survival rate, survival without the recurrence of the tumor, and survival without tumor expansion.”
In light of these data, it is very likely that brief radiation therapy will soon be available to women with breast cancer that has spread to the lymph nodes, which represents 30% of breast cancers overall.
“This means less burdensome treatments, and progress toward reducing the treatment burden,” said Sofia Rivera.
Reducing the number of sessions actually reduces the number of visits patients make to their treatment centers, which is a “gain in terms of quality of life,” Rivera says. It also reduces waiting lists, as more patients become available for radiation therapy.
Oncologist and Cambridge University professor Charlotte Coles described the study as “very important” last Sunday, expecting it to reduce “the burden on patients” and “reduce costs for healthcare systems.”
This study is part of a group of studies in the same direction.
Among these studies is an analysis published last week in the British Medical Journal that combined experiences of more than 20,000 patients and concluded that giving higher doses per fraction of radiotherapy over a shorter period significantly reduces the risk of side effects and improves quality of life.
For breast cancer alone, studies initially showed that 3 weeks of radiation therapy (15 sessions) was as effective as 5 weeks (25 sessions). Other studies have shown that 5 sessions is as effective as 25 or 15 sessions.
The next step will be to test 5 sessions over a week for breast cancer that has spread to the lymph nodes. Studies are underway in this regard, but it will take at least 5 years for the first results to appear.