Characteristics of Anaplastic Oligodendrogliomas Short-Term Survivors: A POLA Network Study

Abstract Background Anaplastic oligodendrogliomas IDH-mutant and 1p/19q codeleted (AO) occasionally have a poor outcome. Herein we aimed at analyzing their characteristics. Methods We retrospectively analyzed the characteristics of 44 AO patients with a cancer-specific survival <5 years (short-term survivors, STS) and compared them with those of 146 AO patients with a survival ≥5 years (classical survivors, CS) included in the POLA network. Results Compared to CS, STS were older (P = .0001), less frequently presented with isolated seizures (P < .0001), more frequently presented with cognitive dysfunction (P < .0001), had larger tumors (P = .= .003), a higher proliferative index (P = .= .0003), and a higher number of chromosomal arm abnormalities (P = .= .02). Regarding treatment, STS less frequently underwent a surgical resection than CS (P = .= .0001) and were more frequently treated with chemotherapy alone (P = .= .009) or with radiotherapy plus temozolomide (P = .= .05). Characteristics independently associated with STS in multivariate analysis were cognitive dysfunction, a number of mitosis > 8, and the absence of tumor resection. Based on cognitive dysfunction, type of surgery, and number of mitosis, patients could be classified into groups of standard (18%) and high (62%) risk of <5 year survival. Conclusion The present study suggests that although STS poor outcome appears to largely result from a more advanced disease at diagnosis, surgical resection may be particularly important in this population

Temozolomide and Radiotherapy versus Radiotherapy Alone in Patients with Glioblastoma, IDH -wildtype: Post Hoc Analysis of the EORTC Randomized Phase III CATNON Trial

In a post hoc analysis of the CATNON trial (NCT00626990), we explored whether adding temozolomide to radiotherapy improves outcome in patients with IDH1/2 wildtype (wt) anaplastic astrocytomas with molecular features of glioblastoma [redesignated as glioblastoma, isocitrate dehydrogenase–wildtype (IDH-wt) in the 2021 World Health Organization (WHO) classification of central nervous system tumors]. Patients and Methods: From the randomized phase III CATNON study examining the addition of adjuvant and concurrent temozolomide to radiotherapy in anaplastic astrocytomas, we selected a subgroup of IDH1/2wt and H3F3Awt tumors with presence of TERT promoter mutations and/or EGFR amplifications and/or combined gain of chromosome 7 and loss of chromosome 10. Molecular abnormalities including MGMT promoter methylation status were determined by next-generation sequencing, DNA methylation profiling, and SNaPshot analysis. Results: Of the 751 patients entered in the CATNON study, 670 had fully molecularly characterized tumors. A total of 159 of these tumors met the WHO 2021 molecular criteria for glioblastoma, IDH-wt. Of these patients, 47 received radiotherapy only and 112 received a combination of radiotherapy and temozolomide. There was no added effect of temozolomide on either overall survival [HR, 1.19; 95% confidence interval (CI), 0.82–1.71] or progression-free survival (HR, 0.87; 95% CI, 0.61–1.24). MGMT promoter methylation was prognostic for overall survival, but was not predictive for outcome to temozolomide treatment either with respect to overall survival or progression-free survival. Conclusions: In this cohort of patients with glioblastoma, IDH-wt temozolomide treatment did not add benefit beyond that observed from radiotherapy, regardless of MGMT promoter status. These findings require a new well-powered prospective clinical study to explore the efficacy of temozolomide treatment in this patient population

Survival outcomes associated with first-line PCV or temozolomide in combination with radiotherapy in IDH-mutant 1p/19q-codeleted grade 3 oligodendroglioma.

International audienc

Incidence and Characteristics of Pseudoprogression in IDH-mutant High-Grade Gliomas: A POLA Network Study.

International audienceBACKGROUND: Incidence and characteristics of pseudoprogression in isocitrate dehydrogenase-mutant high-grade gliomas (IDHmt HGG) remain to be specifically described. METHODS: We analyzed pseudoprogression characteristics and explored the possibility of pseudoprogression misdiagnosis in IDHmt HGG patients, treated with radiotherapy (with or without chemotherapy), included in the French POLA network. Pseudoprogression was analyzed in patients with MRI available for review (reference cohort, n=200). Pseudoprogression misdiagnosis was estimated in this cohort and in an independent cohort (control cohort, n=543) based on progression free survival before and after first progression. RESULTS: In the reference cohort, 38 patients (19%) presented a pseudoprogression after a median time of 10.5 months after radiotherapy. Pseudoprogression characteristics were similar across IDHmt HGG subtypes. In most patients, it consisted in the appearance of one or several infracentimetric, asymptomatic, contrast-enhanced lesions occurring within 2 years after radiotherapy. The only factor associated with pseudoprogression occurrence was adjuvant PCV chemotherapy. Among patients considered as having a first true progression, 7 out of 41 (17%) in the reference cohort and 35 out of 203 (17%) in the control cohort were retrospectively suspected to have a misdiagnosed pseudoprogression. Patients with a misdiagnosed pseudoprogression were characterized by a time to event and an outcome similar to that of patients with a pseudoprogression but presented with larger and more symptomatic lesions. CONCLUSION: In patients with an IDHmt HGG, pseudoprogression occurs later than in IDH-wildtype glioblastomas and seems not only frequent but also frequently misdiagnosed. Within the first 2 years after radiotherapy, the possibility of a pseudoprogression should be carefully considered