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The new classification of tumors of the central nervous system proposed this year by the WHO will also be debated at the meeting

In recent years, a number of new drugs have been approved for the treatment of different types of tumor, a tendency that continues to grow, as major approvals are also expected in the field in the coming years. An ever-changing scenario requiring the full attention of the scientific community, who must review the results obtained from the new treatments, and the combinations of these, both from the biological viewpoint and the pathological. That is why debate forums are so necessary, as is the scientific meeting ‘Advances in Molecular Pathology Diagnosis in the Era of Personalized Cancer Treatment’, jointly hosted by MD Anderson Cancer Center Madrid and The University of Texas MD Anderson Cancer Center Houston on October 5 - 7 in Madrid.

In addition to discussing the newest drugs, these meetings also serve as an opportunity to review the use of some of the treatments already applied in clinical practice for some time. In the words of Dr. Juan Fernando Garcia, head of the Anatomic Pathology Service at MD Anderson Madrid and joint coordinator of the meeting with Joseph Khory, Executive Director, MD Anderson Cancer Network, Division of Pathology/Lab Medicine at MD Anderson Houston, “in pathologies like lung cancer, this review would include target-specific treatments like EGFR or ALK, with which we have more experience, but also new immunomodulating therapies using monoclonal antibodies such as T lymphocyte inhibition with PD-1 or regulation of cytotoxic response mediated by CTLA-4”.

One of the main focuses of this meeting will be immunotherapy because, as stated by Dr. Juan Fernando Garcia, “in the next few years, targeted therapies aimed at the modulation between the tumor cell and its microenvironment (immuno-oncology) will become standard for lung cancer, melanoma, renal cancer and probably pancreatic cancer, too”. For that reason the congress will also include a presentation by Dr. Huamin Wang, Division of Pathology/Lab Medicine at MD Anderson Houston, who has published numerous papers on the functional role of various molecules and signaling pathways in the pathogenesis of the disease.

However, as Dr. Juan Fernando Garcia points out, cancer is a very heterogeneous combination of diseases with very different biologies and mechanisms and, as such, one treatment may be effective for a particular type of tumor, but not necessarily for another. He explains that, “we cannot apply identical rational fundamentals to different cell types and microenvironments and, that is why often extrapolation of treatments from some models of cancer fail on others”.

A problem to which we must also add the selection of the specific subgroup of patients that may benefit more from a determined treatment or sequence of treatments, meaning we must have a clear understanding of the mechanisms of the disease and how different treatments affect it.

Generally, a subgroup of patients is identified on the basis of their sharing certain clinical characteristics, histopathological traits and molecular traits, in addition to being subsidiary to a certain treatment. So, he says, “furthering our knowledge on the biology of diseases also changes the way tumors are classified”.

New classification of CNS tumors

This is happening with, for instance, Central Nervous System (CNS) tumors, which, for the first time, are classified, not only according to their histology, but also by their molecular parameters. The new classification was published by the World Health Organization (WHO) this year and Dr. Juan Fernando Garcia considers it to be “a great conceptual and practical advance over the previous system from 2007”.

In his opinion, the most important factor is that the new classification means there has been an extensive restructuring of diffuse gliomas, medulloblastomas, and other embryonal tumors and that new entities have been incorporated, such as glioblastoma with IDH mutation or diffuse midline glioma with H3 K27M mutation thanks to the incorporation of molecular parameters as a further classification indicator. Other recently identified neoplasms have also been added, whilst other entities have been removed as they are no longer diagnostically and/or biologically relevant.