High-grade astrocytoma with piloid features (HGAP): the Charité experience with a new central nervous system tumor entity

• Published in: Journal of neuro-oncology Vol. 153; no. 1; pp. 109 - 120
• Main Authors: Bender, Katja, Perez, Eilís, Chirica, Mihaela, Onken, Julia, Kahn, Johannes, Brenner, Winfried, Ehret, Felix, Euskirchen, Philipp, Koch, Arend, Capper, David, Kaul, David
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-05-2021; Springer Nature B.V
• Subjects: Astrocytoma; Astrocytoma - diagnostic imaging; Astrocytoma - therapy; Brain cancer; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - therapy; Brain stem; Brain tumors; Central nervous system; Central Nervous System Neoplasms - diagnostic imaging; Central Nervous System Neoplasms - therapy; Cerebellum; Cerebrum; Chemoradiotherapy; Clinical Study; Decision making; Deoxyribonucleic acid; Diencephalon; DNA; DNA methylation; Genomes; Gonadotropin-Releasing Hormone; Histology; Humans; Magnetic Resonance Imaging; Medicine; Medicine & Public Health; Mesencephalon; Nervous system; Neuroimaging; Neurology; Oncology; Patients; Protein Precursors; Radiation therapy; Spinal cord; Surgery; Thorax; Tumors; MC AAP; Methylation-based classification; Case series; High-grade astrocytoma with piloid features; Anaplastic astrocytoma with piloid features; HGAP
• ISSN: 0167-594X; 1573-7373
• DOI: 10.1007/s11060-021-03749-z

Purpose
High-grade astrocytoma with piloid features (HGAP) is a recently described brain tumor entity defined by a specific DNA methylation profile. HGAP has been proposed to be integrated in the upcoming World Health Organization classification of central nervous system tumors expected in 2021. In this series, we present the first single-center experience with this new entity.
Methods
During 2017 and 2020, six HGAP were identified. Clinical course, surgical procedure, histopathology, genome-wide DNA methylation analysis, imaging, and adjuvant therapy were collected.
Results
Tumors were localized in the brain stem (n = 1), cerebellar peduncle (n = 1), diencephalon (n = 1), mesencephalon (n = 1), cerebrum (n = 1) and the thoracic spinal cord (n = 2). The lesions typically presented as T1w hypo- to isointense and T2w hyperintense with inhomogeneous contrast enhancement on MRI. All patients underwent initial surgical intervention. Three patients received adjuvant radiochemotherapy, and one patient adjuvant radiotherapy alone. Four patients died of disease, with an overall survival of 1.8, 9.1, 14.8 and 18.1 months. One patient was alive at the time of last follow-up, 14.6 months after surgery, and one patient was lost to follow-up. Apart from one tumor, the lesions did not present with high grade histology, however patients showed poor clinical outcomes.
Conclusions
Here, we provide detailed clinical, neuroradiological, histological, and molecular pathological information which might aid in clinical decision making until larger case series are published. With the exception of one case, the tumors did not present with high-grade histology but patients still showed short intervals between diagnosis and tumor progression or death even after extensive multimodal therapy.