Correlation between promoter hypermethylation of the O6-methylguanine-deoxyribonucleic acid methyltransferase gene and prognosis in patients with high-grade astrocytic tumors treated with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea-based chemotherapy.

Objective: O(6)-Methylguanine-deoxyribonucleic acid methyltransferase (MGMT) is a deoxyribonucleic acid repair protein associated with the chemoresistance of chloroethylnitrosoureas. We investigated whether MGMT promoter hypermethylation is associated with prognosis in patients with high-grade astrocytic tumors treated uniformly with surgery, radiotherapy, and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU)-based chemotherapy.

Methods: Using the methylation-specific polymerase chain reaction, we assayed promoter hypermethylation of the MGMT gene in tumor deoxyribonucleic acid from 116 adult patients with supratentorial high-grade astrocytic tumors (42 anaplastic astrocytomas [AAs] and 74 glioblastomas multiforme [GBMs]).

Prognostic value of epidermal growth factor receptor in patients with glioblastoma multiforme.

Glioblastoma multiforme (GBM) frequently involves amplification and alteration of the epidermal growth factor receptor (EGFR) gene, resulting in overexpression of varied mutations, including the most common mutation, EGFRvIII, as well as wild-type EGFR (EGFRwt). To test the prognostic value of EGFR, we retrospectively analyzed the relationship between treatment outcomes and the EGFR gene in 87 newly diagnosed adult patients with supratentorial GBM enrolled in clinical trials. The EGFR gene status was assessed by Southern blots and EGFR expression by immunohistochemistry using three monoclonal antibodies (EGFR.

Preliminary observations on genetic alterations in pilocytic astrocytomas associated with neurofibromatosis 1.

Neurofibromatosis 1 (NF1) is an autosomal dominant disorder that predisposes sufferers to various forms of neoplasia. Among affected individuals, 15%-20% develop astrocytomas, especially pilocytic astrocytomas (PA), which are benign and classified as grade I by the World Health Organization. They are generally well circumscribed, and their progression is slow.

Successful treatment of intracranial nongerminomatous malignant germ cell tumors by administering neoadjuvant chemotherapy and radiotherapy before excision of residual tumors.

Object: The goal of this study was to confirm the effectiveness of our novel treatment strategy, neoadjuvant therapy (NAT) consisting of combined chemo- and radiotherapy, which are performed before complete excision of residual tumor in patients with intracranial nongerminomatous malignant germ cell tumors (NGMGCTs).

Methods: The authors treated 11 consecutive patients with NGMGCTs by applying NAT consisting of combined platinum-based chemotherapy and radiotherapy, followed by complete excision of residual tumors. The pretreatment diagnosis, based on tumor markers with or without biopsy, was yolk sac tumor in five patients, embryonal carcinoma in one patient, immature teratoma in one patient, and mixed germ cell tumor containing malignant tumor components in four patients.

Correlation of molecular genetic analysis of p53, MDM2, p16, PTEN, and EGFR and survival of patients with anaplastic astrocytoma and glioblastoma.

This article reviews studies on the correlation between genetic abnormalities in malignant astrocytic tumors and patient survival. It is almost certain that alterations of PTEN on chromosome 10 represent a significant unfavorable prognostic factor in glioblastoma patients. The association of alterations in p53, MDM2, p16 or EGFR with the survival of patients with anaplastic astrocytoma or glioblastoma remains controversial.

Influence of p53 mutations on prognosis of patients with glioblastoma.

Background: The influence of p53 mutations on the biology of astrocytic tumors is controversial. p53 is thought to be inactivated in the early stage of gliomagenesis; however, what role its inactivation plays in the malignancy of gliomas remains unknown. To understand the significance of p53 inactivation, the authors identified the locus of p53 gene mutation in glioma samples at different stages of progression and studied the correlation between the mutation and clinical behavior.

Analysis of homozygous deletion of the p16 gene and correlation with survival in patients with glioblastoma multiforme.

Object: One of the most frequent genetic abnormalities found in patients with glioblastoma multiforme (GBM) is homozygous deletion of the p16 tumor suppressor gene. The authors investigated whether this deletion is associated with prognosis in patients with GBM.

Methods: In 46 adult patients with supratentorial GBM, homozygous deletion of the p16 gene in tumor DNA was examined using the multiplex polymerase chain reaction assay.