Maastro Study of 800 Patients Reveals Personalized Radiotherapy Safely Minimizes Treatment Without Increasing Breast Cancer Recurrence

A 10-year study from Maastro shows that tailoring radiotherapy to a patient's individual risk after chemotherapy results in very low breast cancer recurrence.

By: AXL Media

Published: Mar 25, 2026, 6:32 AM EDT

Source: Information for this report was sourced from European Organisation for Research and Treatment of Cancer

Stratifying Risk Through Chemotherapeutic Response

The clinical management of breast cancer is shifting toward a more nuanced, personalized model that prioritizes the reduction of unnecessary side effects. A decade-long study led by Dr. Fleur Mauritz of the Maastro Radiation Oncology Institute has confirmed that the intensity of radiotherapy can be safely adjusted based on how effectively a patient's cancer responds to initial chemotherapy. By assessing the presence of cancer cells in the lymph nodes following surgery, clinicians can categorize patients into specific risk groups, ensuring that those with a high response receive less radiation while those at higher risk continue to receive comprehensive treatment.

Criteria for Low, Intermediate, and High-Risk Classification

The study followed 848 patients with small tumors (under five centimeters) who initially showed limited spread to one, two, or three lymph nodes. Following chemotherapy and surgery, the cohort was divided into three tiers. Low-risk patients, who showed no remaining cancer in the lymph nodes, received minimal radiotherapy or none at all if they had undergone a mastectomy. Intermediate-risk patients, with one to three affected nodes, received breast irradiation only. High-risk patients, with four or more affected nodes, received full radiotherapy to both the breast and surrounding node areas.

Consistent Long-Term Recurrence Rates Across Groups

Data collected over a ten-year follow-up period revealed a remarkably low overall recurrence rate of only 2.9%. Specifically, the low-risk group experienced a recurrence rate of 2.4%, the intermediate-risk group saw 3.2%, and the high-risk group recorded 2.8%. These figures suggest that scaling back treatment for patients who respond well to chemotherapy does not compromise their long-term safety. Dr. Mauritz emphasized that these reassuring rates demonstrate the viability of omitting radiotherapy completely in selected groups, provided they are categorized accurately through pathological assessment.