Concept of Spectrobiopsy Facing Gliomas: Rational and Future Perspectives Related to Target Therapy

Gliomas represent the most common primary intracranial tumors with an estimated incidence of 31% of all central nervous system neoplasms. Lesions originated from glial cells are extremely heterogeneous, ranging from low grade to high grade with different clinical and biological malignancy. Glioblastoma multiforme (GBM) is the most aggressive and frequent primary malignant tumor of the central nervous system in adults. Even though in the past decades considerable efforts have been made in the therapeutic management of this type of tumor,2 the prognosis after diagnosis of GBM remains extremely poor, reaching a median overall survival of 12–18 months. In 2016 the World Health Organization classified gliomas on the basis of not only phenotypic features but also genotypic ones, underlying the critical role of molecular parameters in the diagnosis, prognosis, and treatment of both low-grade and high-grade gliomas. According to the revised fourth edition of the World Health Organization classification of brain tumors, gliomas are distinguished mainly by the presence or absence of specific mutations involving the isocitrate dehydrogenase (IDH) enzymes, which result in a high concentration of the metabolite 2-hydroxyglutarate and a lack of NADPH, associated with gliomagenesis and progression of glial tumors.