title: Clinical value of chromosome arms 19q and 11p losses in low-grade gliomas.
abstract: BACKGROUND
  Diffuse low-grade gliomas (LGGs) form a heterogeneous subgroup of gliomas in adults. Chromosome (chr) arms 1p/19q codeletion and IDH mutation have been shown to be closely associated with oligodendroglial phenotype and better prognosis. We sought to identify relevant biomarkers in non 1p/19q codeleted LGGs.
  
  
  METHODS
  We characterized a retrospective series of 126 LGGs using genomic arrays, microsatellite analysis, IDH sequencing, MGMT promoter methylation assay, and p53 expression analysis.
  
  
  RESULTS
  Our study confirms that 1p/19q codeletion, mutually exclusive with p53 overexpression, was associated with: (i) better prognosis, (ii) oligodendroglial phenotype, (iii) MGMT promoter methylation, and (iv) IDH mutation. Interestingly, 1p/19q codeleted tumors occur in older patients at diagnosis. Our study shows that non 1p/19q codeleted LGGs can be divided in 5 main genomic subgroups: (i) 11p loss, (ii) 19q loss (iii) 7 gain, (iv) 19 gain, and (v) unclassified. In non 1p/19q codeleted LGGs, we demonstrated that (i) 11p loss is associated with astrocytoma phenotype and has an independent negative prognostic value, and (ii) 19q loss diminished the favorable prognostic value of IDH mutation. Our findings were validated in an independent cohort of 98 LGGs.
  
  
  CONCLUSIONS
  Novel genomic entities and biomarkers have been identified in non 1p/19q codeleted LGGs. Our findings may help to stratify non 1p/19q codeleted LGGs, facilitating future individualization of treatment. Further prospective studies are warranted to support our findings.
authors: Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière (CRICM), UMRS 975, Inserm U 975, CNRS, UMR 7225, Université Pierre et Marie Curie, Paris, France (A.A., Y.M, C.C., B.B., K.M., K.H.-X., M.S., J.-Y.D., A.I.); Department of Neuropathology (H.A., K.M.); Department of Neurology 2-Mazarin (F.L.-D., K.H.-X., M.S., J.-Y.D., A.I.); Department of Neurosurgery, AP-HP, Groupe Hospitalier Pitié-Salpêtriére, Paris, France (L.C.); Department of Neurology (H.F.v.T., J.C.R.); Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands (I.S., P.W., B.Y.); Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands (P.W.).
authors: Agustí
authors: A
authors: Alentorn
authors: Hinke F
authors: HF
authors: van Thuijl
authors: Yannick
authors: Y
authors: Marie
authors: Hussa
authors: H
authors: Alshehhi
authors: Catherine
authors: C
authors: Carpentier
authors: Blandine
authors: B
authors: Boisselier
authors: Florence
authors: F
authors: Laigle-Donadey
authors: Karima
authors: K
authors: Mokhtari
authors: Ilari
authors: I
authors: Scheinin
authors: Pieter
authors: P
authors: Wesseling
authors: Bauke
authors: B
authors: Ylstra
authors: Laurent
authors: L
authors: Capelle
authors: Khê
authors: K
authors: Hoang-Xuan
authors: Marc
authors: M
authors: Sanson
authors: Jean-Yves
authors: JY
authors: Delattre
authors: Jaap C
authors: JC
authors: Reijneveld
authors: Ahmed
authors: A
authors: Idbaih
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000235:genetics; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D016019:Survival Analysis
keywords: IDH; MGMT, TP53; biomarker; genomic array; low-grade gliomas