High-grade gliomas and Lynch syndrome: A retrospective descriptive study with a literature review.

Background: High-grade diffuse gliomas in adults are common malignant primary tumors of the central nervous system. The association with Lynch syndrome (LS) is documented but remains under-researched. However, there are implications for prevention, genetic counseling, and therapeutic approaches. The objective of this study is to conduct a descriptive cohort of patients with high-grade glial tumors in the context of LS. Methods: We included adult patients with glioblastoma (GBM) or grade 4 astrocytoma (WHO 2021 classification) associated with LS, diagnosed at Lille University Hospital or Valenciennes Hospital between 2014 and 2022. We retrospectively collected clinical, radiological, histopathological, molecular, and therapeutic data. Results: We included 6 GBM cases with a median age of 58.7 years (IQR 32.4-63.3). Five cases had Conclusions: GBMs associated with LS exhibit specific histopathological and molecular biology characteristics that may guide syndrome-related research. These tumors could represent a particular subclassification, potentially leading to specific therapies such as immunotherapy. We propose with a review of case in the literature an algorithm for investigating LS upon discovering a GBM. These exploratory results need to be confirmed by a larger cohort.