World health organization grade 2 meningioma treatment
Extent of resection independently predicts progression-free and overall survivals in patients with World health organization grade 2 meningioma. In an era of increasing support for adjuvant treatment modalities in the management of meningiomas. Data support maximal safe resection as the primary goal in the treatment of these patients 1).
The treatment of World Health Organization (WHO) grades 2 and World health organization grade 3 meningiomas remains difficult and controversial. The pathogenesis of high-grade meningiomas was expected to be elucidated to improve treatment strategies. The molecular biology of meningiomas has been clarified in recent years. High-grade meningiomas have been linked to NF2 mutations and 22q deletion. CDKN2A/B homozygous deletion and TERT promoter mutations are independent prognostic factors for WHO grade 3 meningiomas. In addition to 22q loss, 1p, 14p, and 9q loss have been linked to high-grade meningiomas. Meningiomas enriched in copy number alterations may be biologically invasive. Furthermore, several new comprehensive classifications of meningiomas have been proposed based on these molecular biological features, including DNA methylation status. The new classifications may have implications for treatment strategies for refractory aggressive meningiomas because they provide a more accurate prognosis compared to the conventional WHO classification. Although several systemic therapies, including molecular targeted therapies, may be effective in treating refractory aggressive meningiomas, these drugs are being tested. Systemic drug therapy for meningioma is expected to be developed in the future 2).
Adjuvant radiotherapy
Results are still suboptimal with high rates of local progression. A dose escalation using high-conformal RT techniques needs to be evaluated in terms of efficacy and safety. A dose escalation for hRG2 meningiomas, using a Combo-RT approach, is safe and particularly effective in the subgroup of patients with STR 3).
In a large retrospective cohort, Rebchuk et al. from the UBC Hospital, found no survival or local recurrence benefit to adjuvant radiotherapy in the treatment of grade 2 meningiomas. Sensitivity analysis limited to initial GTR and STR also failed to demonstrate any OS or LR benefit with adjuvant radiotherapy. There is a limited utility to upfront adjuvant radiotherapy following initial surgical resection in the treatment of grade 2 meningiomas 4).