Clinical Features and Molecular Markers on Diffuse Midline Gliomas With H3K27M Mutations: A 43 Cases Retrospective Cohort Study

PURPOSE: Diffuse midline gliomas (DMG) with H3K27M mutations have been identified as a rare distinctive entity with unique genetic features, varied molecular alterations, and poor prognosis. The current study aimed to evaluate the clinical characteristics and profile of molecular markers on patients with a DMG harboring H3K27M mutations, and explore the impact of this genetic makeup on overall survival. METHODS: We retrospectively analyzed 43 consecutive patients diagnosed with a DMG harboring H3K27M mutations (age range 3 to 75 years) and treated in a tertiary institution within China between January 2017 to December 2019. Various clinical and molecular factors were evaluated to assess their prognostic value in this unique patient cohort. RESULTS: The median overall survival (OS) was 12.83 months. Preoperative Karnofsky Performance Score (KPS) and adjuvant radiotherapy were found to be independent clinical parameters influencing the OS by multivariate analysis (p = 0.027 and p < 0.001 respectively). Whereas extent of tumor resection failed to demonstrate statistical significance. For molecular markers, P53 overexpression was identified as a negative prognostic factor for overall survival by multivariate analysis (p = 0.030). CONCLUSION: Low preoperative KPS, absence of radiotherapy and P53 overexpression were identified as predictors of a dismal overall survival in patients with DMG and H3K27M mutations.