Clinical and histological characteristics of recurrent oligodendroglial tumors: comparison between primary and recurrent tumors in 18 cases.
Changes in histological and genetic characteristics were investigated in 18 paired primary and recurrent oligodendroglial tumors, using sequencing analysis for isocitrate dehydrogenase (IDH) 1 and 2 gene mutation, Ki-67 and p53 immunohistochemistry, and fluorescent in situ hybridization for loss of heterozygosity of chromosomes 1p and 19q (1p/19q co-deletion). Malignant transformation occurred in 5 of 8 cases with World Health Organization (WHO) grade II tumors, but in 0 of 10 cases with WHO grade III tumors progressing to glioblastoma. Thirteen of the 18 cases carried IDH1 gene mutation. Tumors with IDH1 mutation tended to survive for longer, even after recurrence, but newly developed microvascular proliferation, tumor necrosis, and elevated Ki-67 labeling index were common. Eleven of the 13 IDH1-mutation tumors had either 1p/19q co-deletion or nuclear expression of p53, but all 5 IDH1/2 wild-type tumors had neither. All cases had the same profile for 1p/19q status at recurrence, but nuclear expression of p53 changed from negative to positive in 2 of 6 cases with IDH1 mutation and 1p/19q co-deletion. WHO grade II oligodendroglial tumors show a high rate of malignant transformation, possibly involving p53 in tumors with IDH1 mutation and 1p/19q co-deletion. Tumors with IDH1 mutation had a more aggressive histological phenotype despite their better prognosis.
Department of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
Masayuki
M
Kanamori
Toshihiro
T
Kumabe
Ichiyo
I
Shibahara
Ryuta
R
Saito
Yoji
Y
Yamashita
Yukihiko
Y
Sonoda
Hiroyoshi
H
Suzuki
Mika
M
Watanabe
Teiji
T
Tominaga
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology*; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D005260:Female; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D019394:Ki-67 Antigen / Q000378:metabolism; D019656:Loss of Heterozygosity; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000473:pathology*; D009837:Oligodendroglioma / Q000235:genetics* / Q000473:pathology*; D012189:Retrospective Studies; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human