title: IDH1/2 mutation is a prognostic marker for survival and predicts response to chemotherapy for grade II gliomas concomitantly treated with radiation therapy.
abstract: Reliable prognostic biomarkers of grade II gliomas remain unclear. This study aimed to examine the role of mutations of isocitrate dehydrogenase (IDH1/2), 1p/19q co-deletion, and clinicopathological factors in patients with grade II glioma who were primarily treated with radiotherapy or chemoradiotherapy after surgery. Seventy-two consecutive patients, including 49 cases of diffuse astrocytomas (DA), 4 oligodendrogliomas (OL) and 19 oligoastrocytomas (OA), who underwent treatment from 1991 to 2010 at a single institution were examined. The overall survival (OS) of the DA patients (8.3 years) was significantly shorter than that of the OL and OA patients (11.7 years). IDH1/2 mutations were found in 46.9% of the DA patients and 82.6% of the OL and OA patients. The progression-free survival (PFS) and OS of the patients with IDH1/2 mutations (8.4 and 16.3 years) were significantly longer than those of the patients without IDH1/2 mutations (3.3 and 4.5 years). Among the patients with IDH1/2 mutations, those who were initially treated with chemoradiotherapy including nimustine hydrochloride (ACNU), had significantly longer PFS than those treated with radiotherapy alone, whereas no significant difference in PFS was observed between the chemoradiotherapy and radiotherapy groups in the patients without IDH1/2 mutations. Oligodendroglial tumors, age <40 years, initial Karnofsky performance status (KPS) ≥80, and IDH1/2 mutations were favorable prognostic factors regarding PFS and OS. IDH1/2 mutation was a predictive factor of response to chemoradiotherapy in grade II gliomas. Patients with IDH1/2 mutations may benefit more from chemoraiotherapy than those without IDH1/2 mutations.
authors: Department of Neurosurgery and Neuro-Oncology, National Cancer Center, Tokyo 104-0045, Japan.
authors: Yoshiko
authors: Y
authors: Okita
authors: Yoshitaka
authors: Y
authors: Narita
authors: Yasuji
authors: Y
authors: Miyakita
authors: Makoto
authors: M
authors: Ohno
authors: Yuko
authors: Y
authors: Matsushita
authors: Shintaro
authors: S
authors: Fukushima
authors: Minako
authors: M
authors: Sumi
authors: Koichi
authors: K
authors: Ichimura
authors: Takamasa
authors: T
authors: Kayama
authors: Soichiro
authors: S
authors: Shibui
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D054316:Biomarkers, Pharmacological; D014408:Biomarkers, Tumor / Q000235:genetics; D018572:Disease-Free Survival; D005260:Female; D005910:Glioma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009837:Oligodendroglioma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D011379:Prognosis
chemical_list: D054316:Biomarkers, Pharmacological; D014408:Biomarkers, Tumor; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human