Clinical outcome of surgically treated low-grade gliomas: a retrospective analysis of a single institute.

OBJECTIVE: Low grade gliomas (LGGs) are slow-growing primary brain tumors with heterogeneous clinical behaviors. The aim of our study is to review the treatment outcome of 63 patients with LGGs focusing on surgical outcome and the current therapeutic strategy.

METHODS: We retrospectively enrolled 63 patients surgically treated for LGGs. The gross total resection (GTR) was performed in 35 patients (60.3%), subtotal resection (STR) was performed in 19 patients (31.7%) and partial resection (PR) or biopsy was performed in 9 patients (14.3%). We analyzed their progression-free survival (PFS), overall survival (OS), and malignant transformation with regard to age, gender, Karnofsky performance score (KPS), clinical presentation, tumor location, radiologic pattern, contrast enhancement, extent of removal, pathologic subtype, chemotherapy (CT) and radiotherapy (RT) treatment.

RESULTS: Among all LGGs, the 3-year OS rate was 80% and the 5-year OS was 76%. The 3-year PFS rate was 83.6% and the 5-year PFS was 25%. The non-eloquent area location showed a longer PFS than the eloquent area location (p=0.05). Oligodendroglial pathology showed a longer PFS compared to oligoastrocytomas and astrocytomas (p=0.02). Patients older than 60 years had poorer OS than younger patients (p<0.05). Female gender had a shorter OS than male gender (p<0.05), and a KPS of 90 or 100 had a longer OS than a KPS of 80 (p<0.05). Oligodendroglial pathology statistically correlated with a longer OS (p<0.05).

CONCLUSION: The findings from our study, which were confirmed by uni- and multivariate analyses, demonstrated that radical tumor resection was associated with better long-term outcomes and tumor progression for patients with LGG.