[A molecular classification system for anaplastic glioma].
OBJECTIVE
To project a new molecular classification system for anaplastic gliomas based on the molecular biomarkers.


METHODS
There were 161 patients with histological diagnosis of primary anaplastic gliomas after operation and complete and reliable follow-up data were enrolled in the study from May 2009 to June 2011. A total of 100 male and 61 female patients with a median age of (43 ± 12) years (range: 17-68 years). After the pathology review by 2 experienced neuro-pathologists, 36 anaplastic oligodendroglioma (AO), 66 anaplastic oligoastrocytoma (AOA) and 59 anaplastic astrocytoma (AA) were confirmed. There were 116 patients underwent gross-total resection, 37 sub-total resection and 8 partial resection. Molecular biomarkers evaluated included 1p/19q, IDH1 gene and O6-methylguanine-DNA-methyltransferase (MGMT). Kaplan-Meier plots were compared by Log-rank method.


RESULTS
The survival analysis results showed that the 6-month, 12-month, 18-month and 24-month progression-free survival (PFS) and overall survival (OS) rates of AO was significantly longer than AOA(χ(2) = 12.812 and 6.557, P < 0.05) and AA (χ(2) = 19.125 and 10.206, P < 0.05), but no significant difference of prognosis was observed between AOA and AA (P > 0.05). According to the status of biomarkers, AOA was reclassified into two subgroups-AOA1 and AOA2. AOA1 with 1p/19q co-deletion, IDH1 mutation and/or negative MGMT expression showed similar prognosis with AO (P > 0.05). AOA2 without any biomarkers showed similar prognosis with AA (P > 0.05). Besides, the 6-month, 12-month, 18-month and 24-month PFS and OS rates of patients with AO and AOA1 was significantly longer than patients with AA and AOA2 (PFS:χ(2) = 25.180, P < 0.001; OS: χ(2) = 15.649, P < 0.001). Multivariate analysis showed that the moecular pathology subtypes classified was an independent prognostic factor (PFS: OR = 0.499, 95% CI:0.381-0.653, P < 0.001; OS:OR = 0.605, 95% CI:0.450-0.814, P = 0.001).


CONCLUSIONS
The molecular classification system for anaplastic gliomas will be helpful in estimating patients' prognosis and guiding reasonable therapy for patients with anaplastic gliomas.
Department of Neurosurgery, Beijing Tiantan Hospital Affiliated to Capital Medical University, Beijing 100500, China.
Hai-hui
HH
Jiang
Department of Neurosurgery, Beijing Tiantan Hospital Affiliated to Capital Medical University, Beijing 100500, China.
Xiao-hui
XH
Ren
Department of Neurosurgery, Beijing Tiantan Hospital Affiliated to Capital Medical University, Beijing 100500, China.
Zhe
Z
Zhang
Department of Neurosurgery, Beijing Tiantan Hospital Affiliated to Capital Medical University, Beijing 100500, China. Email: linsong2005@126.com.
Song
S
Lin
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate; D055815:Young Adult