title: Loss of heterozygosity 1p36 and 19q13 is a prognostic factor for overall survival in patients with diffuse WHO grade 2 gliomas treated without chemotherapy.
abstract: OBJECTIVE
  This study was conducted to elucidate the impact of loss of heterozygosity (LOH) for chromosomes 1p36 and 19q13 on the overall survival of patients with diffusely infiltrating WHO grade 2 gliomas treated without chemotherapy.
  
  
  METHODS
  We assessed the LOH status of tumors from patients harboring WHO grade 2 gliomas diagnosed between 1991 and 2000. Patients were either followed after initial biopsy or treated by surgery and/or radiation therapy (RT). Overall survival, time to malignant transformation, and progression-free survival were last updated as of March 2005.
  
  
  RESULTS
  Of a total of 79 patients, LOH 1p36 and LOH 19q13 could be assessed in 67 and 66 patients, respectively. The median follow-up after diagnosis was 6 years. Loss of either 1p or 19q, in particular codeletion(s) at both loci, was found to positively impact on both overall survival (log-rank P < .01), progression-free survival, and survival without malignant transformation (P < .05). Tumor volume (P < .0001), neurologic deficits at diagnosis (P < .01), involvement of more than one lobe (P < .01), and absence of an oligodendroglial component (P < .05) were also predictors of shorter overall survival. The extent of surgery was similar in patients with or without LOH 1p and/or 19q; RT was more frequently resorted to for patients without than for patients with LOH 1p/19q (30% v 60%).
  
  
  CONCLUSIONS
  The presence of LOH on either 1p36 or 19q13, and in particular codeletion of both loci is a strong, nontreatment-related, prognostic factor for overall survival in patients with diffusely infiltrating WHO grade 2 gliomas.
authors.affiliation: Klinik für Neurochirurgie, Universitätsspital Inselspital, CH-3010 Bern, Switzerland. luigi.mariani@insel.ch
authors.forename: Luigi
authors.initials: L
authors.lastname: Mariani
authors.forename: Gianluca
authors.initials: G
authors.lastname: Deiana
authors.forename: Erik
authors.initials: E
authors.lastname: Vassella
authors.forename: Ali-Reza
authors.initials: AR
authors.lastname: Fathi
authors.forename: Christine
authors.initials: C
authors.lastname: Murtin
authors.forename: Marlène
authors.initials: M
authors.lastname: Arnold
authors.forename: Istvan
authors.initials: I
authors.lastname: Vajtai
authors.forename: Joachim
authors.initials: J
authors.lastname: Weis
authors.forename: Peter
authors.initials: P
authors.lastname: Siegenthaler
authors.forename: Martina
authors.initials: M
authors.lastname: Schobesberger
authors.forename: Michael M
authors.initials: MM
authors.lastname: Reinert
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis