SNO ANNUAL MEETING
Sunday, November 16, 8:15am - 10:30am
Location: Loews Hotel, Americana 3
Ken Aldape, Daniel Brat, Arie Perry, Keith Ligon, David Louis, Andreas von Deimling Susan Chang, Mark Gilbert, Warren Mason, Stefan Pfister, Martin van den Bent, Michael Weller, Patrick Wen, Wolfgang Wick, Guido Reifenberger, Mitch Berger, Michael Taylor, Michael Vogelbaum, Gelareh Zadeh, Sofie Salama, Monika Hegi, Roel Verhaak, David Reardon
At the 2014 annual scientific meeting of the Society for Neuro-Oncology (SNO), a session will be dedicated towards the integration of key molecular alterations on the classification of central nervous system tumors. This session is intended to thematically coordinate with and build upon information coinciding with the planned update of the World Health Organization (WHO) classification in 2015. The session aims to invite discussion of the broader audience for SNO and integrate all interested subspecialties within the field of neuro-oncology.
Over the past two decades, we have witnessed a rapid accumulation of molecular discoveries, leading to a more detailed understanding of the molecular subclassification of various brain tumor subtypes. Neuropathologists have taken the first step to recognize the importance of incorporating molecular information into the next WHO classification of central nervous system tumors. A seminal meeting of the neuropathologists with expertise in molecular diagnosis was recently held and results summarized in a consensus report (Brain Pathology, Louis et al July 2014). Key issues included 1) a priority to define diagnostic entities clearly in order to maximize interobserver reproducibility in classification and allow uniform treatment planning; 2) a goal to provide an integrated diagnosis to include both histology and relevant molecular markers, where clinically applicable; 3) an expectation that molecular information be reported for specific diagnostic entities; 4) a recognition that histologically similar entities in the adult and pediatric populations can represent distinct neoplasms with divergent molecular pathogenesis; and finally 5) an input be solicited from experts in complementary disciplines of neuro-oncology.
The proposed SNO session on WHO molecular classification and a follow-up consensus report generated based on this session, is intended to build on the information of the Neuropathologists consensus report, with specific consideration given to receiving feedback the from larger neuro-oncology community. We aim to place this information in a relevant clinical context and with an eye on directing patient management. The ultimate integration of molecular pathology is a long-term multi-phased project, with each phase receiving feedback from all relevant specialties of practice to neuro-oncology.
Examples of clinically poignant questions we face today include the relative importance of histologic and key molecular alterations in diffuse gliomas, specifically 1p/19q loss and IDH mutation. For example, in the setting of known 1p/19q co-deletion status, what is the relative importance of this finding as compared with histologic diagnosis (oligodendroglioma vs, oligoastrocytoma vs. astrocytoma)? Additionally, with the knowledge that IDH-wild type anaplastic astrocytoma (AA) is aggressive relative to IDH-mutant AA, should these entities be classified differently? Conversely, should IDH-mutant glioblastoma (GBM) be classified differently from IDH-wild type GBM? Additional questions of test standardization will be discussed. For example, while ~80-90% of IDH-mutant tumors can be resolved using a simple immunohistochemical stain for the R132H mutation, is there an expectation that the IHC-negative tumors be screened for non-canonical IDH mutations, or is the IHC screen alone sufficient?
These are just examples for discussion and we are considering development of a survey to formalize these questions and gather data related to the use and utilization of molecular tools for classification.
Accordingly, what we aim to establish in this first session at SNO is:
- What is the evidence available that warrants inclusion of specific molecular alterations into tumor classification and patient management?
- Do we have sufficient molecular knowledge to reclassify some brain tumor entities from their traditional histopathological classification and if so how does this alter decision-making for patient management?
- Key molecular alterations to be discussed will include 1p/19q co-deletion, IDH mutation and MGMT methylation in diffuse gliomas, as well as future possibilities of broader molecular tools and signatures as a quality ontrol and adjunct to resolve specific entities found to be difficult to classify by conventional means.