Intense p53 staining is a valuable prognostic indicator for poor prognosisin medulloblastoma/central nervous system primitive neuroectodermal tumors

Intense p53 immunostaining may predict for a poor prognosis in central nerv ous system primitive neuroectodermal tumor of childhood. Background: Medulloblastoma is a common childhood primary brain tumor. Pote ntial prognostic indicators for patients with local disease are age, extent of resection, and gender. However, none of these are well established. Imm unohistologic staining is a potentially useful means to identify high-risk patients. The purpose of this clinical pathologic study was to investigate the prognostic significance of GFAP, synaptophysin, Ki-67, and p53 immunost aining in medulloblastoma/central nervous system primitive neuroectodermal tumors (CNS PNETs.) Materials and methods: The records of 40 patients with CNS PNETs were revie wed. Their surgical specimens were immunostained for p53, glial fibrillary acidic protein (GFAP), synaptophysin, and Ki-67. The p53 specimens were sco red blindly for the intensity of staining of nuclei (intense vs weak) and t he quantity of cells stained. The Ki-67, GFAP, and synaptophysin specimens were analyzed for quantity of cells stained. Results: Ten patients' specimens stained intensely for the p53 protein. Ele ven had weakly staining nuclei. Nineteen specimens had no staining. The pat ients with specimens that stained intensely had a statistically significant decreased disease free survival (P = 0.03). Mere presence or quantity of p 53 nuclear staining did not correlate with disease free survival. Immunohis tochemical staining for Ki-67, GFAP, and synaptophysin did not correlate wi th disease free survival. Clinical parameters of age, gender, and extent of resection also did not approach statistical break significance for disease free survival. Conclusion: Intense nuclear staining for p53 was the only variable in this clinical pathologic study that reached statistical significance for disease free survival. This suggests that intense staining for p53 may be the most important prognostic indicator for non-metastatic CNS PNETs. p53 Immunosta ining with antibodies against p53 in CNS PNETs should be studied in a multi -institutional setting with larger numbers of patients.