title: Chromosome 1p/19q status combined with expression of p53 protein improves the diagnostic and prognostic evaluation of oligodendrogliomas.
abstract: BACKGROUND
  Our previous study confirmed that oligodendrogliomas had higher frequency of chromosome 1p/19q deletion. In order to improve the diagnostic criteria and to predict the prognosis of oligodendroglioma patients, the status of chromosome 1p/19q deletion, the methylation of O(6)-methylguanine-DNA methyltransferase (MGMT), and the expression of p53 protein were evaluated and investigated in relation to patients' outcomes.
  
  
  METHODS
  Methylation of MGMT in 73 cases was analyzed by nested methylation-specific PCR (MSP). The levels of MGMT and p53 protein were tested with immunohistochemistry. Pearson's chi-square test and Fisher's exact test were used. Multivariate and Kaplan-Meier analysis were performed to determine patients' outcomes.
  
  
  RESULTS
  Both oligodendrogliomas and astrocytic gliomas exhibited frequent methylation of MGMT. However, the results of MSP did not completely correspond to that of the immunohistochemical staining for MGMT. The expression of p53 protein was more frequently observed in patients without a 1p or 19q deletion in anaplastic oligodendrogliomas (P = 0.032, 0.025). In low-grade oligodendrogliomas, methylation of MGMT was more frequent in patients with 1p/19q deletion than in patients with 1p/19q intact (P = 0.038). Patients with oligodendrogliomas with 1p/19q loss of heterozygosity and p53-negative showed a longer progression-free survival.
  
  
  CONCLUSIONS
  Detection of chromosome 1p/19q status combined with p53 protein immunohistochemistry might be beneficial to improve the pathological diagnosis and to determine the prognosis of patients with oligodendrogliomas.
authors.affiliation: Department of Neuropathology, Institute of Neurology, Huashan Hospital of Fudan University, Shanghai 200040, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Xiong
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Rong-Hu
authors.initials: RH
authors.lastname: Ke
authors.forename: Ying
authors.initials: Y
authors.lastname: Mao
authors.forename: Zhu-Rong
authors.initials: ZR
authors.lastname: Ye
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics; D001932:Brain Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D002648:Child; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics; D045643:DNA Repair Enzymes / Q000235:genetics; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D011379:Prognosis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes