title: Supratentorial gliomas: a comparative study by grade and histologic type.
abstract: OBJECTIVE
  To try and identify biologic differences based on tumor grade and histologic type between the major classes of glial tumors, including low-grade diffuse fibrillary and pilocytic astrocytomas, oligodendrogliomas, and mixed oligo-astrocytomas and high-grade diffuse fibrillary astrocytomas, oligodendrogliomas and mixed oligo-astrocytomas.
  
  
  METHODS
  Utilizing the St. Anne-Mayo (SAM) grading system, the incidence, patient characteristics, and survivals of 196 patients with low-grade (SAM grade 1 + 2) and 318 patients with high-grade (SAM 3 + 4) supratentorial tumors were compared.
  
  
  RESULTS
  Among low-grade tumors, most favorable were 5- and 10-year survival rates for patients with pilocytic astrocytomas, which were 85% and 79%, respectively. Median survival and 5- and 10-year survival rates for the other low-grade tumors were lower, and were proportionately improved by the presence of an oligodendroglial component: diffuse fibrillary astrocytomas-4.7 years, 46%, and 17%, oligodendroglioma-9.8 years, 73%, and 49%; and mixed oligo-astrocytoma-7.1 years, 63%, and 33%, respectively. For high-grade tumors, patients with either oligodendrogliomas or mixed oligo-astrocytomas had comparable favorable survivals in comparison to diffuse fibrillary astrocytomas. Median survivals and 5- and 10-year survival rates were 4.5 years, 45%, and 15% for the oligodendrogliomas and mixed oligo-astrocytomas versus 0.8 years, 3%, and 0% for the diffuse fibrillary astrocytomas, respectively.
  
  
  CONCLUSIONS
  These survival data suggest that both low-grade and high-grade supratentorial gliomas have outcomes which are highly dependent upon histologic type.
authors.affiliation: Division of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: E G
authors.initials: EG
authors.lastname: Shaw
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: J R
authors.initials: JR
authors.lastname: O'Fallon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000401:mortality* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005910:Glioma / Q000401:mortality / Q000473:pathology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000401:mortality* / Q000473:pathology; D015173:Supratentorial Neoplasms / Q000401:mortality* / Q000473:pathology; D016019:Survival Analysis