Open AccessPleomorphic Xanthoastrocytoma: Natural History and Long‐Term Follow‐Up
Author(s) -
Ida Cristiane M.,
Rodriguez Fausto J.,
Burger Peter C.,
Caron Alissa A.,
Jenkins Sarah M.,
Spears Grant M.,
Aranguren Dawn L.,
Lachance Daniel H.,
Giannini Caterina
Publication year - 2015
Publication title -
brain pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.986
H-Index - 132
eISSN - 1750-3639
pISSN - 1015-6305
DOI - 10.1111/bpa.12217
Subject(s) - pleomorphic xanthoastrocytoma , anaplasia , medicine , immunohistochemistry , pathology , mitotic index , necrosis , idh1 , v600e , gastroenterology , mutation , oncology , astrocytoma , biology , glioma , mitosis , cancer research , biochemistry , gene , microbiology and biotechnology
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/ 10HPF 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/ 10HPF 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/ 10HPF . 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.