title: Pleomorphic Xanthoastrocytoma: Natural History and Long-Term Follow-Up.
abstract: Prognostic significance of histological anaplasia and BRAF V600E mutation were retrospectively evaluated in 74 patients with pleomorphic xanthoastrocytoma (PXA). Median age at diagnosis was 21.5 years (31 pediatric, 43 adult) and median follow-up 7.6 years. Anaplasia (PXA-AF), defined as mitotic index ≥ 5/10 HPF and/or presence of necrosis, was present in 33 cases. BRAF V600E mutation was detected in 39 (of 60) cases by immunohistochemical and/or molecular analysis, all negative for IDH1 (R132H). Mitotic index ≥ 5/10 HPF and necrosis were associated with decreased overall survival (OS; P = 0.0005 and P = 0.0002, respectively). In all cases except two, necrosis was associated with mitotic index ≥ 5/10 HPF. Patients with BRAF V600E mutant tumors had significantly longer OS compared with those without BRAF V600E mutation (P = 0.02). PXA-AF patients, regardless of age, had significantly shorter OS compared with those without (P = 0.0003). Recurrence-free survival was significantly shorter for adult PXA-AF patients (P = 0.047) only. Patients who either recurred or died ≤ 3 years from diagnosis were more likely to have had either PXA-AF at first diagnosis (P = 0.008) or undergone a non-gross total resection procedure (P = 0.004) as compared with patients who did not. This study provides further evidence that PXA-AF behaves more aggressively than PXA and may qualify for WHO grade III "anaplastic" designation.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Cristiane M
authors.initials: CM
authors.lastname: Ida
authors.affiliation: Department of Pathology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Fausto J
authors.initials: FJ
authors.lastname: Rodriguez
authors.affiliation: Department of Pathology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Burger
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Alissa A
authors.initials: AA
authors.lastname: Caron
authors.affiliation: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Jenkins
authors.affiliation: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Grant M
authors.initials: GM
authors.lastname: Spears
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Dawn L
authors.initials: DL
authors.lastname: Aranguren
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Lachance
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Caterina
authors.initials: C
authors.lastname: Giannini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000708:Anaplasia; D001254:Astrocytoma / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAF V600E; IDH1 R132H; WHO grade; anaplastic; glioma; pleomorphic xanthoastrocytoma