Path-07. Infratentorial High-grade Gliomas: Neurosurgical Case Series With Molecular Analysis
Year: 2021
Type: conference-abstract
Abstract: INTRODUCTION Most high grade gliomas (HGG) are located supratentorially, while less than 1% arise infratentorially. Growing evidence suggests that infratentorial HGGs (iHGG) represent a collection of distinct molecular entities and that further elucidation of their molecular features can help guide management. We perform here a clinical and molecular analysis of our institutional iHGG case series. METHODS We retrospectively reviewed iHGG patients treated surgically at Brigham and Women’s Hospital (1992-2020), and evaluated their history of prior malignancies, tumor location, treatment, molecular profile, tumor recurrence, and survival. iHGG were identified by review of pathology records, using WHO Histologic Grading Criteria as grade III-IV gliomas located infratentorially. Molecular analysis data was obtained from pathology records. RESULTS Among 37 iHGGs, 16 (43%) were glioblastomas, 11 (30%) were anaplastic astrocytomas, 2 (5%) were diffuse midline gliomas, 2 (5%) were infiltrating gliomas, 2 (5%) were anaplastic ependymomas, 1 (3%) was an anaplastic oligodendroglioma, and 3 (8%) were HGG not otherwise specific. Sixteen (43%) patients were female, median age was 49 years. Fifteen patients had history prior malignancy, 11 of which received radiation and 8 chemotherapy. Surgical resection of iHGG included gross total resection in 4 (11%) and subtotal in 33 (89%). Twenty-one patients (57%) received adjuvant radiation and 19 (51%) chemotherapy. At follow-up, 13 (35%) patients demonstrated symptomatic deterioration, 15 (41%) were stable, and 7 (19%) were improved. Seven patients (19%) experienced recurrence at a mean time of 19 months, and one-year survival was 35%. Molecular analysis revealed 7/15 (47%) tumors were MGMT promoter methylated, IDH was mutated in 3/24 (13%), EGFR was amplified in 3/10 (30%), CDKN2A/B homozygous deletion in 4/7 (57%), TP53 was mutated in 14/15 (93%), and H3K27M was present in 4/10 (40%). CONCLUSIONS iHGGs demonstrate substantial distinction from their supratentorial counterparts. Herein we examined their clinical course, molecular features, management, and outcomes.
Source: Neuro-Oncology
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W3217155587