title: Objective response to radiation therapy and long-term survival of patients with WHO grade II astrocytic gliomas with known LOH 1p/19q status.
abstract: BACKGROUND
  WHO grade II gliomas are often approached by radiation therapy (RT). However, little is known about tumor response and its potential impact on long-term survival.
  
  
  METHODS
  Patients subjected to RT were selected from the own database of WHO grade II gliomas diagnosed between 1991 and 2000. The volumetric tumor response after RT was assessed based on magnetic resonance imaging and graded according to standard criteria as complete, partial (PR, >or= 50%), or minor (MR, 25% to <50%).
  
  
  RESULTS
  There were 24 astrocytomas and three oligoastrocytomas. 21 patients (78%) were dead at follow-up (mean survival 74 months). None of the patients had chemotherapy. Objective response occurred in 14 patients (52%, five PR and nine MR) but was not associated with overall survival. The vast majority of the tumors had no loss of heterozygosity (LOH) 1p and/or 19q (86%).
  
  
  CONCLUSIONS
  Approximately 50% of patients with astrocytic WHO grade II gliomas respond to RT despite the absence of LOH for 1p/19q. The potential predictive factors for response and the impact of response on overall survival remain unclear.
authors.affiliation: Department of Neurosurgery, University Hospital, Inselspital Bern, Switzerland.
authors.forename: Ali-Reza
authors.initials: AR
authors.lastname: Fathi
authors.forename: Erik
authors.initials: E
authors.lastname: Vassella
authors.forename: Marlene
authors.initials: M
authors.lastname: Arnold
authors.forename: Jürgen
authors.initials: J
authors.lastname: Curschmann
authors.forename: Michael
authors.initials: M
authors.lastname: Reinert
authors.forename: Istvan
authors.initials: I
authors.lastname: Vajtai
authors.forename: Joachim
authors.initials: J
authors.lastname: Weis
authors.forename: Gianluca
authors.initials: G
authors.lastname: Deiana
authors.forename: Luigi
authors.initials: L
authors.lastname: Mariani
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002878:Chromosomes, Human, Pair 1 / Q000528:radiation effects*; D002888:Chromosomes, Human, Pair 19 / Q000528:radiation effects*; D016371:Cranial Irradiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D019656:Loss of Heterozygosity / Q000528:radiation effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D016019:Survival Analysis; D017741:Survivors