Reply to “The time has come for an integrated and multiscale grading system for oligodendrogliomas IDH-mutant and 1p/19q co-deleted mixing imaging and histomolecular parameters”
Year: 2025
Type: letter
Abstract: We thank Prof. J. Pallud for his letter following our publication “Reappraisal of prognostic factors in CNS WHO grade 3 oligodendrogliomas, IDH-mutant and 1p/19q co-deleted: Lessons from the French Pola cohort.”1 We will respond to the three comments/suggestions raised by Prof. J. Pallud: First, we acknowledge the usefulness to set up a cohort of CNS WHO grade 2 oligodendrogliomas, IDH-mutant and 1p/19q co-deleted (grade 2 Oligos) in order to improve Oligos’ grading. Such a cohort will allow us to compare our group 1 of grade 3 Oligos (high mitotic count only) that do not display contrast enhancement (CE) with grade 2 Oligos (with or without CE) to evaluate the impact of CE and mitotic index in Oligos that do not display microvascular proliferation, necrosis nor CDKN2A homozygous deletion. Second, we thank Prof. J. Pallud for giving us the opportunity to precise how CE was defined. In our study, we considered that a tumor was contrast-enhanced if we observed nodular-like, ring-like, or faint and patchy CE. A previous study reported that only nodular- and ring-like CE were associated with worse survivals in WHO grade II gliomas2; however, at this time, IDH status was not recorded and we cannot exclude that some IDH-wildtype gliomas were included. Moreover, CE prognostic value was not specifically assessed in Oligos. In contrast, in a study specifically focusing on Oligos, faint and patchy enhancement CE was associated with a higher growth rate and more frequent growth rates ≥ 8 mm/year compared to Oligos without CE.3 Nevertheless, we agree that a standardization of the interpretation of neuroimaging data will be required before its putative inclusion into the grading of Oligos.
Source: Neuro-Oncology
Institutions: Centre National de la Recherche Scientifique, Aix-Marseille Université, Institut de Neurophysiopathologie, Hôpital de la Timone, Inserm, Sorbonne Université, Assistance Publique – Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Institut du Cerveau, Lyon 1 Université, Hospices Civils de Lyon, Centre de Recherche en Cancérologie de Lyon
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W4409569439