P10.24 Outcome evaluation of patients with newly diagnosed anaplastic gliomas treated in a single institution using a multimodal approach: review according to the new 2016 World Health Organization (WHO) classification system
Authors: F. Pessina, P. Navarria
Journal: Neuro-Oncology (2017)

Background: Anaplastic gliomas represent less than 10% of newly diagnosed primary brain tumors. In the last years, comprehensive and integrative genomic and molecular analysis led to identify biologic classes with clinically distinct behavior and to determine whether gliomas are more accurately defined by molecular status than by histological features. Based on this background we evaluated the outcome of patients with newly diagnosed anaplastic glioma treated in our institution reviewing this series in relation to the 2016 WHO classification suggestions. Methods: This retrospective study included patients with newly diagnosed anaplastic gliomas underwent surgery plus adjuvant chemotherapy (CHT) alone or concomitant and adjuvant chemo-radiotherapy (CHTRT). Surgery was performed in all patients with the aim to maximally remove the tumor according with functional boundaries. The extent of resection (EOR) was defined as Complete resection(CR) in case of residual tumor volume lower than 1.0cm3, subtotal resection(SR) between 1.0cm3 and 10.0cm3 and partial resection(PR) greater than 10.0cm3. The adjuvant treatment proposed was CHT in case of young patients with oligodendroglial tumors, IDH-mutated and 1p/19q-codeleted, underwent CR; in all the other cases RT with concurrent and adjuvant TMZ was performed. The total RT dose prescribed was 60 Gy in 30 fractions. Three classes have been defined in relation to the molecular parameters: class I IDH mutated and 1p/19q codeleted tumors; class II IDH mutated and 1p/19q no codeleted tumors; class III IDH wild type tumors. Response was recorded using the Response Assessment in Neuro-Oncology (RANO) criteria. Results: From January 2008 to May 2014, 123 patients were treated. According with histopathological features, 54 (43.9%) patients had diagnosis of AO, 36 (29.3%) of AOA, and 33 (26.8%) of AA. Considering molecular parameters, 69 (56.1%) patients were in class I, 39 (31.7%) in class II and 15 (12.2%) in class III. All patients underwent surgical resection; adjuvant chemotherapy alone with TMZ was performed in 51 (41,5%) patients and RT with concurrent and adjuvant TMZ in 72 (58.5%). The median follow up time for the whole cohort was 35.1 months (range 9.3-95.7 months) and 35.6 months (range 19.2-95.7 months) for the alive patients. The median PFS time and the 2, 3, 5 years PFS rate were 27 months, 65.5% 21.2%, 21.2%; the 2, 3, 5 years OS rate were 89.7%, 83.0%, 58.4%. On univariate and multivariate analysis factors conditioning survival were KPS, EOR, IDH1 mutation status, and presence of 1p-19q codeletion. Conclusion: A stratification of patients by clinical and molecular features and a revision according with 2016 WHO classification of CNS tumors resulted more predictive and prognostic on outcome of anaplastic glioma patients. The treatment choice have to consider molecular assessment and, in our experience, the extent of surgical resection.