Clinical Factors for Prognosis and Treatment Guidance of Spinal Cord Astrocytoma

Seki, Toshitaka; Hida, Kazutoshi; Yano, Shunsuke; Aoyama, Takeshi; Koyanagi, Izumi; Sasamori, Toru; Hamauch, Shuji; Houkin, Kiyohiro

Abstract

STUDY DESIGN: Retrospective study. PURPOSE: To obtain information useful in establishing treatment guidelines by evaluating baseline clinical features and treatment outcomes of patients with spinal cord astrocytoma (SCA). OVERVIEW OF LITERATURE: The optimal management of SCA remains controversial, and there are no standard guidelines.
METHODS
The study included 20 patients with low-grade and 13 with high-grade SCA surgically treated between 1989 and 2014. Patients were classified according to the extent of surgical resection. Survival was assessed using Kaplan-Meier plots and compared between groups by log-rank tests. Neurological status was defined by the modified McCormick scale and compared between groups by Mann-Whitney U tests.
RESULTS
Surgical resection was performed for 19 of 20 low-grade (95%) and 10 of 13 high-grade (76.9%) SCA patients. Only nine patients (27.3%) underwent gross total resection, all of whom had low-grade SCA. Of all patients, 51.5% showed deteriorated neurological status compared to preoperative baseline. Median overall survival was significantly longer for low-grade SCA than that (91 months, 78% at 5 years vs. 15 months, 31% at 5 years; p=0.007). Low-grade SCA patients benefited from more aggressive resection, whereas high-grade SCA patients did not. Multivariate analysis revealed histology status (hazard ratio [HR], 0.30; 95% confidence interval [CI], 0.09-0.98; p<0.05) and postoperative neurological status (HR, 0.12; CI, 0.02-0.95; p<0.05) as independent predictors of longer overall survival. Adjuvant radiotherapy had no significant impact on survival rate. However, a trend for increased survival was observed with radiation cordotomy (RCT) in high-grade SCA patients.
CONCLUSIONS
Aggressive resection for low-grade and RCT may prolong survival. Preservation of neurological status is an important treatment goal. Given the low incidence of SCA, establishing strong collaborative, interdisciplinary, and multi-institutional study groups is necessary to define optimal treatments.