In a large cohort of 911 high-grade IDH-mutant gliomas from the French national POLA network, we investigated the prognostic value of the CDKN2A gene homozygous deletion as well as WHO grading criteria (mitoses, microvascular proliferation, and necrosis).
We showed that:
- CDKN2A homozygous deletion characterizes diffuse malignant IDH-mutant gliomas with worst outcome.
- Microvascular proliferation stratifies IDH-mutant gliomas lacking CDKN2A homozygous deletion.
These results are of interest for a future grading approach of IDH-mutant gliomas and will be included in cIMPACT-NOW update as well as in the future WHO classification of central nervous system tumours.