title: Clinicopathological analysis of nine consecutive central nervous system primitive neuroectodermal tumors in a single institute.
abstract: The objective of this study was to determine the outcome of central nervous system primitive neuroectodermal tumors (CNS PNETs) and to clarify the histopathological findings as prognostic factors. We performed a retrospective analysis of nine consecutive patients with CNS PNETs who underwent treatment at our institute between 1993 and 2011. All patients were treated by surgical resection followed by chemoradiotherapy. Additional treatment, including surgical resection, was performed at relapse. Expression of immunohistochemical markers was examined for neuronal, astrocytic, mesenchymal, and epithelial differentiation, and also for TP53, O(6)-methylguanine-DNA methyltransferase, and Ki-67. Five-year progression-free survival was 18.2 % and the overall survival was 52.5 %. Five the 9 patients had recurrence and 4 patients died during the median follow-up period of 41.1 months. All 4 patients died of dissemination not local recurrence. After relapses, the extent of differentiation was different in each case and TP53 changed to positive or negative, but the Ki-67 labeling index did not reveal any differences between primary and recurrent tumors. A treatment procedure to prevent and treat dissemination of CNS PNETs should be established. Because the pathological change after relapse was different in each case, definitive histopathological prognostic factors for CNS PNETs are still difficult to propose.
authors.affiliation: Department of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
authors.forename: Misaki
authors.initials: M
authors.lastname: Aizawa-Kohama
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kumabe
authors.forename: Ryuta
authors.initials: R
authors.lastname: Saito
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanamori
authors.forename: Yoji
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Sonoda
authors.forename: Mika
authors.initials: M
authors.lastname: Watanabe
authors.forename: Teiji
authors.initials: T
authors.lastname: Tominaga
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D006801:Humans; D007223:Infant; D008297:Male; D018242:Neuroectodermal Tumors, Primitive / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D012008:Recurrence; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor