Vimentin and Survivin Expression Rates as Prognostic Factors in Medulloblastoma

ABSTRACT

BACKGROUND: A medulloblastoma is a primitive neuroepithelial tumor of the cerebellum that occurs in children and metastasizes through the cerebrospinal fluid. It is highly malignant and invasive, and the 5-year survival rate is only 60%. Surgical resection techniques, radiation, and chemotherapy have improved the overall survival but the patients suffer life-long cognitive dysfunctions or endocrine abnormalities as the side effects of treatment. Therefore it is essential to identify prognostic markers to determine the appropriate treatment strategy in order to minimize the side effects. METHODS: This study evaluated the immunohistochemical differentiation and survival rate with synaptophysin, glial fibrillary acidic protein, epithelial membrane antigen, vimentin and primitive neuroepithelial marker nestin of 55 paraffin-embedded medulloblastomas, using a tissue microarray. The expression of survivin, the apoptotic inhibitor, and the survival rate with regard to the proliferation index of Ki-67 were also investigated. RESULTS: The group testing positive to vimentin, a mesenchymal differentiation marker, had a worse prognosis and there was a strong correlation between vimentin expression and nestin expression. Patients with a survivin expression rate >35% had a significantly poorer clinical course and there was a correlation between the survivin expression rate and Ki-67 expression rate. CONCLUSION: In conclusion, vimentin and survivin are negative prognostic markers in medulloblastomas.