Management of IDH-mutant astrocytoma based on WHO 2021 classification of central nervous system tumors: a single center retrospective study

Abstract Purpose: The diagnosis of glioma has got an advance since the WHO 2021 classification published with more molecular alternations involved in the integrate diagnoses pathways. Our study was aimed to show our experience on the clinical features and management of astrocytoma, IDH-mutant based on latest WHO classification. Methods: Patients diagnosed with astrocytoma, IDH-mutant based on WHO 5th edition classification of CNS tumors at our center from Jan 2009 to Jan 2022 were included, and divided to WHO 2-3 grade group and WHO 4 grade group. Integrate diagnoses according to WHO 2016 and 2021 classification were confirmed retrospectively. Clinical and MRI features were reviewed and survival analysis was done. Results: A total of 60 patients were included. 21.43% (6/28) of patients diagnosed with grade II and 58.33% (7/12) of patients with grade III by WHO 4th edition classification changed into grade 4 by WHO 5th classification. Sex, recurrent glioma and Ki-67 index of pathological exam were statistically different in WHO grade 2-3 group (n=27) and WHO grade 4 group (n=33). CDK6, FGFR2, MYC alterations shown an enrichment in WHO grade 4 group. Patients with higher grade shown shorter mOS (mOS=75.9m, 53.6m, 26.4m for grade 2, 3, 4 respectively). FGFR2 alternations was associated with worse survival for patients with astrocytoma, IDH-mutant, WHO grade 4 (p=0.013). Conclusion: Patients changed diagnoses as WHO grade 4 by 2021 WHO classification had worse prognoses, and treatment should be tailored personally for them. More researches of the management of IDH-mutant astrocytoma are needed in the future.