Prognosis in patients with anaplastic oligoastrocytoma is associated with histologic grade.
BACKGROUND
Anaplastic oligoastrocytomas (AOA) are relatively uncommon high-grade gliomas. While oligodendroglial elements are thought to be associated with better outcomes, the magnitude of the difference is not clear.


METHODS
Between 1980 and 1999, Mayo Clinic and the NCCTG conducted 10 trials of radiation therapy and chemotherapy in adults with newly-diagnosed high-grade gliomas. All pathology slides were reviewed by one of the authors (BWS or CG). We grouped patients by cell type and grade, compared survival distributions by the log-rank statistic, and performed multiple variable analyses.


RESULTS
Of 1368 patients, 68 (5%) had AOA, including 21 Grade 3 (OA3) and 47 grade 4 (OA4), 153 (11%) had anaplastic astrocytoma (AA), and 1147 (84%) had glioblastoma multiforme (GBM). Patients with OA3 survived significantly longer than those with OA4 (P=0.0001) or AA (P=0.0044). Patients with OA4 lived significantly longer than those with GBM (P=0.0005). The same differences were noted for PFS. Prognostic factors for survival identified by multiple variable analysis were histology, age, ECOG performance score, and extent of surgical resection, but not treatment administered.


CONCLUSIONS
Patients with anaplastic oligoastrocytoma have distinct outcomes based upon grade (OA3 vs. OA4) and in comparison with pure astrocytoma (AA or GBM). Future trials which include more than one histologic entity need to report results by cell type and grade and account for the varying prognoses in interpreting treatment outcomes.
Buckner
Jan C
JC
Division of Medical Oncology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. buckner.jan@mayo.edu
O'Fallon
Judith R
JR
Dinapoli
Robert P
RP
Schomberg
Paula J
PJ
Farr
Gist
G
Schaefer
Paul
P
Giannini
Caterina
C
Scheithauer
Bernd W
BW
Ballman
Karla V
KV
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001254:Astrocytoma / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D001932:Brain Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis