Astrocytic tumors are the commonest type of glioma in adults. Glioblastomas (GB, WHO malignancy grade IV) make up approximately 50% of all gliomas and are the most malignant subtype. They may arise de novo or progress from diffuse astrocytomas (A, WHO malignancy grade II) or anaplastic astrocytomas (AA, WHO malignancy grade III).
Classification
pilocytic astrocytomas (Grade I)
fibrillary astrocytomas (Grade II)
anaplastic astrocytomas (Grade III)
glioblastoma multiforme (Grade IV)
Cancer genes
inactivated tumor suppressor genes (TSG)
- CDKN2A/CDKN2B (9p21)
- PTEN (10q23)
- RB1 (13q14)
amplifications of proto-oncogenes
CGH
deletions
- Chr.6 loss
- Chr.9 loss
- Chr.10 loss (monosomy 10, partial deletions of distal 10q, 10q LOH)
- Chr.13 loss
- Chr.22 loss
- 1p loss
- 4q loss
- 6q loss
- 9p loss
- 13q loss
- 14q loss
- 15q loss
- 17p loss
- 19q loss
- 22q loss
gains
- Chr.7 gain
- Chr.12 gain
- 3q gain
- 8q gain
- 9q gain
- 10p gain
- 17q gain
- Chr.19 gain (trisomy 19)
- Chr.20 gain (trisomy 20)
References
Konopka G, Bonni A. Signaling pathways regulating gliomagenesis. Curr Mol Med. 2003 Feb;3(1):73-84. PMID: 12558076