In an effort to synthesize findings from multiple guidelines on various management approaches for brain metastases, ASCO, the Society for Neuro-Oncology (SNO), and the American Society for Radiation Oncology (ASTRO) spearheaded the development of a novel publication to inform and update physician decision-making. The new guideline helps fill a knowledge gap given that previous guidelines failed to incorporate medical therapies for brain metastases.1
“Prior guideline efforts in brain metastasis care were, for the most part, produced by neurosurgeons and radiation oncologists via their respective professional organizations. But over the past decade, the treatment options for certain types of brain metastases have undergone a radical change,” said Expert Panel Co-Chair Michael Vogelbaum, MD, PhD, of Moffitt Cancer Center. “The new role for medical oncologists in treating both the extra central nervous system (CNS) disease and brain metastases indicated the need for a new set of guidelines that would evaluate the quality and extent of evidence supporting the use of systemic therapy for the primary treatment of brain metastases and place this evidence in the context of that supporting the established treatments delivered via neurosurgical and radiation oncology procedures.”
Michael Vogelbaum, MD, PhD
David Schiff, MD
The end result is what Dr. Vogelbaum and fellow Expert Panel Co-Chair David Schiff, MD, of the University of Virginia Medical Center, call the most comprehensive set of multidisciplinary guidelines for the treatment of brain metastases ever published.
Collective Findings
The effort by ASCO, SNO, and ASTRO was intended to coalesce findings from numerous guidelines published over the past 20 years by several medical professional societies representing diverse medical disciplines as well as recent findings from clinical trials on the use of medical therapies for brain metastases.
“The need for multidisciplinary participation was clear from the start, and surgical, medical, neuro-, and medical oncologists were included,” Dr. Schiff said. “Although this was [initially] conceived as a joint effort between ASCO and SNO, several panel members were radiation oncologists. And all parties readily agreed that adding a radiation oncology co-chair and obtaining ASTRO approval would avoid redundancy and add to the credibility of the guidelines.”
The guideline further updates the oncology field on rapid advances in combination therapy and systemic treatments for metastatic brain cancer care while additionally clarifying topics where previous guidelines offered ambiguous or contradictory advice, such as on the use of stereotactic radiosurgery vs whole-brain therapy vs a combination of the two.
The expert panel performed a systematic review of randomized and nonrandomized evidence from January 2008 to April 2020. They also evaluated evidence supporting almost all currently used treatments for brain metastases, regardless of whether they were supported by prospective randomized studies. Consequently, the guideline offers numerous recommendations about the availability and outcomes of surgical, systemic, and radiation therapies as well as the effects of timing of these interventions on clinical outcomes.
For example, the guideline emphasizes the importance of local therapies—surgery or stereotactic radiosurgery—and articulates when these modalities are feasible. It also highlights situations in which local therapy or whole-brain radiotherapy can be deferred in place of chemotherapy, targeted therapy, or immunotherapy depending on tumor histology and molecular features. The expert panel also delineated how, in many cases, either stereotactic radiosurgery or hippocampal-avoidant whole-brain radiotherapy with memantine can be utilized to avoid the cognitive toxicity of whole-brain radiotherapy.
“Our recommendations on the use of local therapy for patients who are symptomatic and asymptomatic highlight the multidisciplinary approach that should be taken for the management of these complex patients,” Dr. Vogelbaum said. “Treatment of brain metastases should not be seen the same as the treatment of metastases to most other organs. There are unique considerations that must be accounted for when cancer spreads to the CNS, and neuro-oncologists, neurosurgeons, and radiation oncologists—who routinely treat CNS tumors—have a specialized expertise for addressing cancer in the CNS.”
Real-World Implementation
The guideline could have significant implications for medical oncologists, who are typically familiar with the impact of targeted therapies and immunotherapies on extra CNS disease and are likely to be enthusiastic about the promise they appear to have on CNS metastases. However, Dr. Vogelbaum said that medical oncologists also need to be aware of the limitations in the evidence supporting the efficacy and durability of these therapies and recognize the local control benefits and durability associated with previously established treatments of brain metastases.
In addition, because of the multiplicity of currently available interventions—including surgery, laser interstitial thermal therapy, stereotactic radiosurgery, whole-brain radiotherapy with and without hippocampal avoidance, targeted therapies, and immunotherapy—even specialists may struggle to keep pace with the latest treatment options and their benefits. So, they too should benefit from the guideline, as it serves as a roadmap for making evidence-based treatment decisions.
“This guideline represents one of the first—if not the first—systematic efforts to assess which systemic therapies are of documented benefit in brain metastases,” Dr. Schiff said. “In this era of burgeoning new therapies and clinical trials, having this literature digested in one place will have great utility for clinicians of multiple subspecialties.
REFERENCE
Originally published in ASCO Daily News. © American Society of Clinical Oncology. ASCO Daily News, December 22, 2021. All rights reserved.
