A ten-year study presented at the 15th European Breast Cancer Conference (EBCC15) in Barcelona on Mar. 24 found that personalized radiotherapy based on individual patient risk after chemotherapy and surgery keeps breast cancer recurrence rates very low.
The findings are significant because they suggest that scaling back radiotherapy for certain patients could reduce side effects without increasing the risk of cancer returning. The approach tailors treatment depending on whether there are signs of remaining cancer cells in the lymph nodes after initial therapies.
Dr Fleur Mauritz, a radiation oncologist in training at Maastro, Maastricht Radiation Oncology Institute in The Netherlands, presented the research. "For many patients with breast cancer, the first treatment is chemotherapy. This can shrink the tumor and kill off any cancer cells that are starting to spread into the body, before surgery," Mauritz said. She added: "We know that radiotherapy reduces the risk of breast cancer recurrence... This study examined whether it's possible to scale back radiotherapy in patients whose cancer shows a good response when chemotherapy is given prior to surgery."
The study involved 848 patients treated at 17 centers across The Netherlands between 2011 and 2015. After chemotherapy and surgery, patients were grouped by their level of remaining risk: those with no signs of lymph node involvement received minimal or no further radiotherapy; intermediate-risk patients received targeted treatment; high-risk groups had more extensive irradiation.
Over ten years, only 2.9% (24 out of 838) experienced a local recurrence. In low-, intermediate-, and high-risk groups, recurrence rates were similar—ranging from about 2.4% to 3.2%. "The results of our study show that tailoring the extent of radiotherapy according to how well the chemotherapy has worked... leads to very low and reassuring recurrence rates," Mauritz said.
Mauritz noted this was the first long-term demonstration for this group but cautioned most participants underwent axillary lymph node dissection—a practice less common today—and that randomized trial results from the USA will be needed for final conclusions.
Professor Isabel Rubio from Clínica Universidad de Navarra commented: "Reducing radiotherapy after chemotherapy appears safe in terms of the risk of recurrence... Overall, this study reinforces that stratifying patients by risk... helps to ensure the most appropriate approach while avoiding both overtreatment and undertreatment."
