Abstract 770P
Background
The WHO CNS5 2021 classification revolutionized CNS tumor classification by emphasizing molecular characteristics over histopathology alone. Previously, tumors were classified solely by morphology until the 2016 update introduced molecular markers like IDH for gliomas and 1p19q codeletion for oligodendrogliomas. The 2021 update further refined this, categorizing IDH wild-type gliomas uniformly as glioblastoma due to poor prognosis, regardless of histology or grade. This study compares survival outcomes based on the 2016 and 2021 classifications in high grade glioma patients treated at our institution.
Methods
This retrospective cohort study included high-grade glioma patients treated between 2018 and 2022 at AIIMS, Jodhpur. Inclusion criteria were grade 3 or 4 gliomas receiving adjuvant radiotherapy. Exclusions were non-glial CNS malignancies, brain metastasis, diffuse midline gliomas, incomplete records, and inaccurate contact details. Data on diagnosis, histopathology, molecular profiling, treatment response, and patient status were collected. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier survival analysis in SPSS version 26, with progression defined from symptom onset and survival measured from diagnosis to death.
Results
For the entire cohort, median OS was 19 months with Stupp protocol treatment versus 3 months without. Reclassified by the 2016 system, glioblastoma IDH mutant was most common (32.8%), whereas the 2021 system classified astrocytoma grade 4 most frequently (41.4%). OS and PFS significantly correlated with the 2021 classification (p<0.05), demonstrating improved diagnostic relevance. Univariate Cox regression confirmed this (p=0.002).
Conclusions
The study concludes that the CNS5 classification correlates more significantly with survival compared to previous systems, simplifying diagnosis and aiding treatment decisions. This real-world evidence supports the practicality and prognostic value of the WHO CNS5 classification in CNS tumors.
Clinical trial identification
Editorial acknowledgement
During the preparation of this abstract, the author used ChatGPT version 3.5 in order to decrease the number of characters to set limit of 2000. After using the tool, I have reviewed and edited the content as needed and take full responsibility for the content of the publication.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.