Modern views on the recurrence of meningiomas

Abstract

Meningiomas are common tumors of the central nervous system. Grade I meningiomas are generally considered to be "benign". However, a certain percentage of these tumors have a more aggressive course, similar to malignant tumors. Numerous observations have shown that even in the case of radical removal of the tumor, the latter recur within the next 10 years. Recent molecular studies have shed new light on meningioma subtypes, their behavior, the prospect of new treatment, and prognostic features for patients. The study of V.E. Clark et al. found a number of mutations in NF2 meningiomas, namely TRAF7 (tumor necrosis factor receptor 7 factor), KLF4 (Kruppel-like factor 4c), AKT1 and SMO. The pattern between the type of mutation and the tumor location was established: posterior cranial fossa, parasagittal area, falx, torculae and intraventricular sections - loss of NF2 or chromosome 22, olfactory groove and middle cranial fossa - KLF4 / TRAF7, olfactory groove, - PIK3CA, middle parts of the anterior cranial fossa and middle cranial fossa - AKT1 / POLR2, olfactory groove - SMO. The selection criteria in the study, which analyzed data from 469 meningiomas of a known molecular subgroup, were the degree of resection, postoperative irradiation, postoperative neuroimaging and time to recurrence (if present). Molecular subgroups of meningiomas had different clinical manifestations during the two years of follow-up, with several aggressive subgroups (NF2, PI3K, HH, TRAF7) recurring at an average rate 22 times faster than less aggressive tumors (KLF4, POLR2A, SMARCB1). PI3K-activated meningiomas recurred earlier than tumors in other groups. The potentially more aggressive group of meningiomas with HH, NF2, and TRAF7 mutations demonstrated a high recurrence rate after 60 months of follow-up (35.3, 43.7, and 36.4%, respectively), whereas most tumor recurrences with PI3K mutations were reported within the first 24 months (75,0%). Classification of meningiomas by genomic mutations is a promising tool. Its introduction into clinical practice will make it possible to predict the aggressiveness of meningiomas and the risk of their recurrence, which will help to give a more accurate prognosis for patients and develop effective therapeutic methods for these tumors.