Adjuvant Radiotherapy Halves Recurrence Risk in WHO Grade 2 Atypical Meningioma
Adjuvant fractionated radiotherapy significantly improves disease-free survival and cuts the risk of tumor recurrence in half compared with observation alone following complete surgical resection of newly diagnosed WHO grade 2 atypical meningioma. These findings from a phase 3, open-label, multicenter trial were published online on September 25 in The Lancet. The study demonstrates a 5-year disease-free survival rate of 79.9% for patients receiving radiotherapy, compared with 64.3% for those in the observation group.
International Clinical Trial Design Across 58 Hospitals
Led by Michael D. Jenkinson from the Institute of Systems, Molecular and Integrative Biology at the University of Liverpool, the ROAM/EORTC-1308 trial evaluated 157 randomized patients across 58 hospitals in 11 countries. Researchers assessed 990 patients for eligibility before assigning 78 participants to the radiotherapy arm and 79 participants to the observation group. All enrolled individuals were at least 16 years old and had undergone surgeon-assessed complete resection of an atypical meningioma. Radiotherapy consisted of external-beam intensity-modulated treatment delivering 60 Gy in 30 fractions over 6 weeks, with prospective central quality-assurance review conducted before treatment commenced.
Recurrence Rates and Molecular Risk Analysis
At a median follow-up of 64 months, researchers documented tumor recurrence in 11 of 78 patients (14%) who received radiotherapy, contrasted with 24 of 79 patients (30%) kept under observation. Radiotherapy was associated with a lower hazard of recurrence or death, yielding a hazard ratio of 0.51. In post hoc analyses incorporating molecular data, adjuvant radiotherapy maintained its association with improved disease-free survival after adjusting for the DNA methylation class and the integrated molecular risk score.
Adverse Events and Quality of Life Outcomes
Serious adverse events related to radiotherapy occurred in 5 of 66 participants, which included two early events and three late events, with zero treatment-related deaths recorded. Health-related quality of life and neurocognitive function remained similar between both study arms. Writing on LinkedIn, Miguel Bronchud noted that atypical meningiomas account for 25% to 30% of all meningiomas and carry a high risk of recurrence even after complete surgical removal, highlighting the uncertainty surrounding the role of adjuvant radiotherapy.
Trial Limitations and Funding Sources
The trial faced certain constraints, including local assessment of pathology and MRI recurrence without central review, along with an inability to mask treatment assignment. A total of 41 recurrence or death events occurred during the trial, falling below the prespecified target of 46 events. Additionally, 12 participants assigned to the radiotherapy group did not undergo treatment, which potentially understated the true treatment effect. Financial support for the trial was provided by the National Health and Medical Research Council of Australia, the European Organisation for Research and Treatment of Cancer Brain Tumour Group and Radiation Oncology Group, and the National Institute for Health and Care Research Health Technology Assessment programme.
Frequently Asked Questions About Atypical Meningioma Radiotherapy
What is a WHO grade 2 atypical meningioma?
Atypical meningiomas are primary brain tumors categorized by the World Health Organization as grade 2, meaning they possess a higher risk of recurrence than benign grade 1 tumors even after complete surgical removal.
How was the radiation dose administered in the trial?
Patients in the treatment arm received external-beam intensity-modulated radiotherapy delivering a total dose of 60 Gy split into 30 fractions administered over a period of 6 weeks.
What were the primary financial and institutional backers of the study?
Financial backing for the project came from the National Health and Medical Research Council of Australia, the European Organisation for Research and Treatment of Cancer Brain Tumour Group and Radiation Oncology Group, and the National Institute for Health and Care Research Health Technology Assessment programme.
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