Study Finds Improved Survival for Young Patients With Brain Metastases Who Receive Stereotactic Radiosurgery Alone
Cancer patients with limited brain metastases (one to four tumors) who are 50 years old and younger should receive stereotactic radiosurgery without whole-brain radiotherapy, according to a study by Saghal et al in the International Journal of Radiation Oncology • Biology • Physics. Researchers at the University of Toronto found that for patients 50 years old and younger who received stereotactic radiosurgery alone, survival was improved by 13%, compared with patients 50 years old and younger who received both stereotactic radiosurgery and whole-brain radiotherapy.
Study Background
This study analyzed patient data from the three largest randomized clinical trials of stereotactic radiosurgery and whole-brain radiotherapy conducted to date: the Asian trial (JROSG99-1) by Aoyama et al, published in 2006; the North American trial (MDACC NCT00548756) by Chang et al, published in 2009; and the European trial (EORTC 22952-26001) by Kocher et al, published in 2011. A total of 364 patients from the three randomized controlled trials were evaluated for this meta-analysis.
Of those 364 patients, 51% (186) were treated with stereotactic radiosurgery alone, and 49% (178) received both stereotactic radiosurgery and whole-brain radiotherapy. Nineteen percent (68) of patients were 50 years of age and younger, and 61% (19) of these patients had a single brain metastasis. Twenty percent (72) of all patients had local brain failure, the occurrence of progression of previously treated brain metastases, and 43% (156) experienced distant brain failure, the occurrence of new brain metastases in areas of the brain outside the primary tumor sites.
Study Findings
The impact of age on treatment effectiveness revealed stereotactic radiosurgery alone yielded improved overall survival in patients 50 years old and younger. Patients 50 years old and younger who received stereotactic radiosurgery alone had a median survival of 13.6 months after treatment and a 65% improvement, as opposed to 8.2 months for patients 50 years old and younger who were treated with stereotactic radiosurgery plus whole-brain radiotherapy. Patients older than 50 years had a median survival of 10.1 months when treated with stereotactic radiosurgery alone and 8.6 months when treated with stereotactic radiosurgery plus whole-brain radiotherapy.
“We expected to see a survival advantage favoring combined therapy of stereotactic radiosurgery and whole-brain radiotherapy. However, these data clearly demonstrate the benefit for stereotactic radiosurgery alone to improve survival for our younger patients with limited brain metastases,” said lead author of the study Arjun Sahgal, MD, Associate Professor of Radiation Oncology and Surgery at the University of Toronto, and a radiation oncologist at the Odette Cancer Centre of the Sunnybrook Health Sciences Centre.
“Furthermore, it was previously thought that the positive effect of whole-brain radiation in reducing the risk of distant brain relapse was generalizable for all patients. However, we did not observe this effect in patients 50 years and younger with limited brain metastases. In these patients, the same rate of distant brain failure was observed, despite treatment with whole-brain radiation. This result, together with our survival result, gave rise to the hypothesis that if patients are treated with whole-brain radiation without realizing the benefits of improving distant brain control, then survival may be adversely affected. Therefore, our subgroup meta-analysis has swung the pendulum in favor of stereotactic radiosurgery alone as the standard of care,” he concluded.
Dr. Sahgal is the corresponding author of the International Journal of Radiation Oncology • Biology • Physics article.
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