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. 2025 Mar 7;27(3):755-766.
doi: 10.1093/neuonc/noae221.

Reappraisal of prognostic factors in CNS WHO grade 3 oligodendrogliomas IDH-mutant and 1p/19q co-deleted: Lessons from the French POLA cohort

Domique Figarella-Branger  1   2 , Carole Colin  3   2 , Karima Mokhtari  4   5 , Emmanuelle Uro-Coste  6   7   8 , Ahmed Idbaih  9   10   4 , Romain Appay  1   2   11 , Emeline Tabouret  2   12   11 , Mehdi Touat  10   4 , Antoine Seyve  13 , Catherine Carpentier  4 , Caroline Dehais  10   4 , François Ducray  13   14 ; POLA network
Collaborators, Affiliations

Reappraisal of prognostic factors in CNS WHO grade 3 oligodendrogliomas IDH-mutant and 1p/19q co-deleted: Lessons from the French POLA cohort

Domique Figarella-Branger et al. Neuro Oncol. .

Abstract

Background: In the POLA cohort, 3 pathological groups of CNS WHO grade 3 oligodendroglioma IDH-mutant and 1p/19q co-deleted have been described: group 1 (high mitotic count only), group 2 (microvascular proliferation MVP and no necrosis), and group 3 (MVP and necrosis).

Methods: 494 patients from the POLA cohort, with a median follow-up of 96 months were included. To identify the impact of the pathological groups and contrast enhancement (CE) in group 1 on overall survival (OS) or progression-free survival (PFS), survival curves were obtained (Kaplan-Meier method) and compared (log-rank test). The prognostic value of clinical factors and CDKN2A homozygous deletion HD were also tested. Multivariate analysis was performed.

Results: Survival analysis demonstrated that the pathological groups were associated with both progression-free survival (PFS P = .01) and overall survival (OS P = .001). In group 1, patients with CE (1CE+) had a poorer prognosis compared to those without (OS P = .028, PFS P = .006). Further stratification into group 1CE-, group 1CE+, group 2, and group 3 provided clearer prognostic distinctions (OS P = .002, PFS P < .0001). Other prognostic factors included age (OS P < .0001, PFS P = .002), extent of surgical resection (OS P = .001, PFS P = .003), KPS (OS P < .0001, PFS P = 0.002), postoperative treatment (OS P = .007, PFS P < .0001), and CDKN2A HD (OS and PFS P < .0001). The pathological groups remained of prognostic significance for PFS in multivariate analysis.

Conclusions: Necrosis and CDKN2A HD are adverse prognostic factors of WHO grade 3 oligodendrogliomas, IDH-mutant, and 1p/19q co-deleted. Besides, in group 1 patients, lack of CE is a factor of better prognosis.

Keywords: CDKN2A HD; CNS WHO grade 3 oligodendroglioma IDH-mutant and 1p/19q co-deleted; contrast enhancement; microvascular proliferation; mitoses; necrosis.

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Conflict of interest statement

Outside this work: A.I. has received research grants from Sanofi, Nutritheragene, Transgene, and Servier, travel funding from Carthera, Léo Pharma and Novocure, consulting fees from Novocure, Leo Pharma, Polytone Laser, Novartis, and Boehringer Ingelheim, and honoraria from Novocure and Neurologies. F.D. has received honoraria for symposium or advisory board participation from Servier and Novocure. E.T. has received honoraria for lectures or advisory board participation from Novocure, Servier, Léo Pharma and Gliocure and research grant (IIS) from Serb. M.T. has received research grants from Sanofi, consulting fees from Servier, Novocure, Ono and Resilience, honoraria for advisory board participation from Servier and Novocure. Other authors declare that they have no conflict of interest.

Figures

Figure 1.
Figure 1.
Kaplan–Meier estimates of overall survival (OS) (A) and progression-free survival (PFS) (B) for the whole POLA cohort of 494 patients with centrally reviewed confirmation of newly diagnosed IDH-mutant, 1p/19q-co-deleted CNS WHO grade 3 oligodendroglioma. Five-year OS and PFS and 10-year OS and PFS are indicated by dotted lines.
Figure 2.
Figure 2.
Kaplan–Meier estimates of overall survival (OS) and progression-free survival (PFS) for patients belonging to: initial pathological groups (A-B): mitoses only (group 1), microvascular proliferation (MVP) without necrosis (group 2) and MVP and necrosis (group 3); groups including contrast enhancement (CE) stratification in group 1 (C-D); new groups (E-F): mitoses only, no CE (group 1CE-), mitoses and CE and MVP without necrosis (group Angiogenesis = 1CE + and group 2), MVP and necrosis (group 3). Five-year OS and PFS and 10-year OS and PFS are indicated by dotted lines.
See this image and copyright information in PMC

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