Prognostic Analysis of Clinical and Immunohistochemical Factors for Patients with Spinal Schwannoma

BACKGROUND: Schwannoma comprises approximately 25% of all spinal tumors, but there is little information published in the literature regarding this subject. Our aim in this study was to discuss diagnostic and prognostic factors for spinal schwannoma. METHODS: A retrospective study was performed to analyze the clinical and immunohistochemical data of patients with spinal schwannoma surgically treated in our center between 2005 and 2013. RESULTS: A total of 524 patients with spinal schwannoma were included in the study. The mean follow-up period was 58.3 months. Forty-eight patients developed recurrence, and 26 died. Findings from the statistical analyses suggested duration of preoperative symptoms, Sridhar classification, tumor size, bone damage, Ki67 labeling index, and S100 expression were different between benign schwannoma and the malignant subtype. Recurrence was associated with resection mode, segments of involvement, pathology grade, CD57 expression, Ki67 labeling index, and 5100 expression. The overall survival was closely related with recurrence, location in sacrum, pathology grade, Ki67 labeling index, and P53 expression. CONCLUSIONS: Compared with the benign subtype, malignant schwannoma has a shorter duration of preoperative symptoms, larger tumor size, greater Sridhar classification, and poorer prognosis. Total resection can significantly reduce recurrence but not guarantee a better survival, which is associated location and pathology grade. A Ki67 labeling index >5% was not only an index for malignant subtype but also a prognostic indicator for recurrence and poor survival. Moreover, S100-negative was a prognostic indicator for recurrence, whereas P53-positive was associated with a poor prognosis.