title: Prognostic value of 1p, 19q, 9p, 10q, and EGFR-FISH analyses in recurrent oligodendrogliomas.
abstract: Although 1p/19q codeletions define "genetically favorable" oligodendrogliomas, eventual tumor progression and patient death remain constant. Genetic testing is often performed at the time of recurrence, though it is unclear whether these or other genetic alterations provide useful prognostic information. We characterized 138 of 189 (73%) available primary and recurrent oligodendroglial neoplasms from 80 patients, utilizing paired FISH probes for 1p32/1q42, 19p13/19q13, CEP7/EGFR, CEP9/p16, and PTEN/DMBT1. Patients were followed until death (49%), or a median follow-up of 8.9 years. Patients with 1p/19q codeleted tumors (71%) had an estimated overall median survival of 14.9 years with an estimated 3.9 years from first recurrence. In contrast, those lacking deletions had significantly lower estimated overall median survivals of 4.7 years and 1.0 year after first recurrence (both p < 0.001). This increased survival in patients with 1p/19q codeleted tumors remained significant when adjustments were made for age, tumor grade, type of surgical procedure, and treatment with radiation or chemotherapy. Only 1 recurrence showed focal EGFR amplification, while 5 developed 10q deletions, mostly in high-grade mixed oligoastrocytomas lacking 1p/19q deletions. In contrast, p16 (9p21) deletions were common and associated with both high grade (p < 0.001) and recurrence (p = 0.002). Our data suggest that in classic oligodendrogliomas: 1) 1p/19q tumor status is a powerful predictor of patient survival, even after recurrence; 2) p16 deletions are common progression-associated alterations; and 3) 10q deletions and EGFR amplifications are sufficiently rare to suggest the possibility of alternate diagnoses.
authors.affiliation: Division of Neuropathology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0007, USA.
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Fallon
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Palmer
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Roth
authors.forename: L Burton
authors.initials: LB
authors.lastname: Nabors
authors.forename: Wenquan
authors.initials: W
authors.lastname: Wang
authors.forename: Mark
authors.initials: M
authors.lastname: Carpenter
authors.forename: Ruma
authors.initials: R
authors.lastname: Banerjee
authors.forename: Peter
authors.initials: P
authors.lastname: Forsyth
authors.forename: Keith
authors.initials: K
authors.lastname: Rich
authors.forename: Arie
authors.initials: A
authors.lastname: Perry
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001932:Brain Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009364:Neoplasm Recurrence, Local; D009837:Oligodendroglioma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors