title: Updated therapeutic strategy for adult low-grade glioma stratified by resection and tumor subtype.
abstract: The importance of surgical resection for patients with supratentorial low-grade glioma (LGG) remains controversial. This retrospective study of patients (n = 153) treated between 2000 to 2010 at a single institution assessed whether increasing the extent of resection (EOR) was associated with improved progression-free survival (PFS) and overall survival (OS). Histological subtypes of World Health Organization grade II tumors were as follows: diffuse astrocytoma in 49 patients (32.0%), oligoastrocytoma in 45 patients (29.4%), and oligodendroglioma in 59 patients (38.6%). Median pre- and postoperative tumor volumes and median EOR were 29.0 cm(3) (range 0.7-162 cm(3)) and 1.7 cm(3) (range 0-135.7 cm(3)) and 95%, respectively. Five- and 10-year OS for all LGG patients were 95.1% and 85.4%, respectively. Eight-year OS for diffuse astrocytoma, oligoastrocytoma, and oligodendroglioma were 70.7%, 91.2%, and 98.3%, respectively. Five-year PFS for diffuse astrocytoma, oligoastrocytoma, and oligodendroglioma were 42.6%, 71.3%, and 62.7%, respectively. Patients were divided into two groups by EOR ≥90% and <90%, and OS and PFS were analyzed. Both OS and PFS were significantly longer in patients with ≥90% EOR. Increased EOR resulted in better PFS for diffuse astrocytoma but not for oligodendroglioma. Multivariate analysis identified age and EOR as parameters significantly associated with OS. The only parameter associated with PFS was EOR. Based on these findings, we established updated therapeutic strategies for LGG. If surgery resulted in EOR <90%, patients with astrocytoma will require second-look surgery, whereas patients with oligodendroglioma or oligoastrocytoma, which are sensitive to chemotherapy, will be treated with chemotherapy.
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, Tokyo Women's Medical University, Kawada-cho, Shinjuku-ku, Tokyo, Japan. ymuragaki@abmes.twmu.ac.jp
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nitta
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Muragaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Maruyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iseki
authors.forename: Soko
authors.initials: S
authors.lastname: Ikuta
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Konishi
authors.forename: Taichi
authors.initials: T
authors.lastname: Saito
authors.forename: Manabu
authors.initials: M
authors.lastname: Tamura
authors.forename: Michael
authors.initials: M
authors.lastname: Chernov
authors.forename: Atsushi
authors.initials: A
authors.lastname: Watanabe
authors.forename: Saori
authors.initials: S
authors.lastname: Okamoto
authors.forename: Katsuya
authors.initials: K
authors.lastname: Maebayashi
authors.forename: Norio
authors.initials: N
authors.lastname: Mitsuhashi
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Okada
mesh_terms: D000367:Age Factors; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001254:Astrocytoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D003399:Craniotomy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009837:Oligodendroglioma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D011379:Prognosis; D012086:Reoperation; D012189:Retrospective Studies; D015996:Survival Rate; D014041:Tokyo; D047368:Tumor Burden / Q000502:physiology