Prognostic Factors and Treatment of Spinal Astrocytomas: A Multi-institutional Cohort Analysis.

STUDY DESIGN

Retrospective cohort analysis of patients with spinal astrocytoma from multi-institutional data and the literature.

OBJECTIVE

To determine the prognostic factors, treatment, and survival of patients.

SUMMARY OF BACKGROUND DATA

Our current understanding of the epidemiology, prognosis, and optimal treatment of spinal astrocytoma is limited. The literature is confined to case reports or small institutional case series.

METHOD

Patient demographics, tumor characteristics, treatments, and outcomes were extracted. Univariate Kaplan-Meier survival analysis was performed to identify prognostic factors followed by multivariate Cox proportional hazard analysis. Wilcoxon signed-rank test was performed on pre- and postoperational functional status as measured by McCormick score.

RESULTS

Ninety-four patients from four institutions and 339 patients from the literature were included. For the multi-institutional cohort, WHO grade IV tumors had shorter progression-free survival (PFS) than those of lower grades, whereas gross total resection (GTR) (hazard ratio [HR]: 0.41, 95% confidence interval [CI]: 0.14-1.27, P = 0.124) trended toward longer PFS when compared to subtotal resection (STR). Age 18 years or older, paresthesia as a presenting symptom, and higher WHO grade were associated with shorter overall survival (OS), whereas thoracic tumor location when compared to cervical tumor location, biopsy when compared to STR, and radiotherapy (HR: 0.42, 95% CI: 0.20-0.88, P = 0.022) were associated with longer OS. For the literature cohort, GTR (HR 0.43, 95% CI: 0.24-0.77, P = 0.005) was associated with longer PFS when compared to STR, whereas higher WHO grade was associated with shorter PFS. Higher WHO grade and recurrence/progression were associated with shorter OS. Postoperative McCormick score was significantly higher than preoperative score (P < 0.001), but subgroup analysis of the change in McCormick score by extent of resection revealed no differences among groups (P = 0.551).

CONCLUSION

In patients with spinal astrocytomas, GTR likely resulted in longer PFS when compared to STR. Adjuvant radiotherapy appears to be effective in improving survival outcomes for high-grade tumors.

LEVEL OF EVIDENCE