Anaplastic Astrocytoma Group Research Articles

T2/T2-FLAIR mismatch sign as a predictive biomarker for anaplastic astrocytoma genetic profile

T2/T2-FLAIR mismatch sign as a predictive biomarker for anaplastic astrocytoma genetic profile

Survivin, caspase-3 and MIB-1 expression in astrocytic tumors of various grades

PurposeGliomas are the most common primary brain tumors. The etiology is still unclear and the progression from low to high-grade gliomas is frequent. The molecular mechanisms are quite established, however the heterogeneity of glioblastomas force the scientist to look for the new therapeutic targets. The aim of the study was to evaluate the caspase-3 and survivin expression in correlation with MIB-1 expression in gliomas of various grade to assess the apoptosis in gliomas and to determinate new possible targets for the future therapy. Material and methodsWe identified 131 patients with a histopathological diagnosis of astrocytic tumors (diffuse astrocytoma, anaplastic astrocytoma and glioblastoma). The evaluation of caspase-3, survivin and MIB-1 expression was done using immunohistochemical methods. ResultsCaspase-3 and survivin expression was observed both in low- and high-grade astrocytomas. The differences in expression were the most evident in glioblastoma group. All primary glioblastomas (31 cases) expressed caspase-3. In secondary glioblastoma group only 17 out of 30 specimens were positive for caspase-3. Survivin expression was observed in 80.6% primary glioblastomas and in all examined secondary glioblastomas and the staining was strong and diffuse in all cases. MIB-1 expression was low in diffuse astrocytomas (DA) and ranged between 1 and 5%. In anaplastic astrocytoma group it was ranged between 5 and 10% and the highest percentage of the positive cells was observed in glioblastoma cases and ranged from 10% even to 30%. The most evident MIB-1 expression was observed in the cells surrounding the pathological blood vessels and necrosis. ConclusionsThe high incidence of survivin and caspase-3 expression in diffuse and anaplastic astrocytoma cases may suggest, that the regulation between pro- and antiapoptotic proteins may play an important role in tumor growth and progression. The overexpression of survivin and MIB-1 expression in glioblastoma cases also may confirm the theory about the important role of anti-apoptotic and proliferation processes in glioblastoma progression and as such may be potential therapeutic targets.

A Phase II Study of Antineoplastons A10 and AS2-1 in Adult Patients with Primary Brain Tumors—Final Report (Protocol BT-09)

Antineoplastons A10 and AS2-1 (ANP) are synthetic derivatives of glutamine, isoglutamine, and phenylacetic acid. In 1993, a phase II clinical trial program began according to protocols based on the initial protocol, BT-06, which was transferred from the National Institutes of Health (NIH). Protocol BT-09 was designed for different types of primary brain tumors in adults that were not curable by standard treatment. The study was designed as a single arm, two-stage, phase II trial of ANP as a monotherapy in a high-risk, poor-prognosis population. The total number of registered subjects was 40. The majority of patients were diagnosed with high-grade tumors (N = 33). In this group, 12 patients carried diagnosis of anaplastic astrocytoma (AA) and 11 patients of glioblastoma. In the group of low-grade tumors (N = 7), there were 6 cases of low-grade glioma, and 1 neurocytoma grade 2. A group of 12 patients did not receive any prior treatment, 12 patients had surgical resection only, 5 patients received radiation therapy (RT) only, and 11 patients received both RT and chemotherapy. The median duration of ANP was 16.6 weeks. The median dosage of A10 was 7.16 g/kg/d and AS2-1 was 0.27 g/kg/d. Responses were accessed by gadolinium-enhanced magnetic resonance imaging (MRI). Objective responses (OR) in all patients were 22.5% and in the AA group were 41.7% of patients. The median progression-free survival (PFS) in the AA group was 5.4 months. The median overall survival (OS) was 12.7 months and OS at 1 and 2 years was 54.5% and 45.5% correspondingly. The treatment was well-tolerated with reversible grade 3 and 4 toxicities in 35% of all patients (N = 40). In conclusion, the study reached efficacy endpoint and ANP was well-tolerated and compared favorably to the current treatment of AA.

Promoter hypermethylation-mediated down-regulation of RUNX3 gene in human brain tumors

The Runx family proteins, including RUNX3, are tissue-restricted transcription factors and play role in neuronal development and tumorigenesis. RUNX3 has an important role in glioblastoma (GBM) tumorigenesis because of its promoter hypermethylation. We aimed to evaluate the methylation-mediated expression regulation of RUNX3 gene in brain tumors. Cases of meningiomas WHO grade III (3), anaplastic astrocytomas (3), diffuse astrocytoma (3), and GBM (12) were recruited into this study. Real-time quantitative PCR was performed for analyses of DNA promoter methylation and analyses of methylation-mediated expression status of RUNX3 gene was performed by real-time quantitative RT-PCR. There was no significant difference between methylated and unmethylated quantitative ratio of RUNX3 gene promoter region and also no significant difference in relative ratio of RUNX3 gene expression in brain tumor groups. Methylated and unmethylated ratio in anaplastic astrocytoma, diffuse astrocytoma, GBM, meningioma (WHO grade III) and in all groups were; 1.44, 1.09, 1.51, 1.52 and 1.43, respectively. One allele was found methylated necessarily. No methylation was detected in one case of GBM group and one case of anaplastic astrocytoma group. There was no unmethylated promoter in one of the GBM cases. There were significant differences between relative ratio of RUNX3 gene expression and methylated/unmethylated ratio rates for all cases (p = 0.001) and GBM groups (p = 0.041). This study overemphasized the RUNX3 gene importance in brain tumors, due to the existence of at least one methylated allele.

Immunohistochemical staining of DNA topoisomerase IIalpha in human gliomas.

The enzyme DNA topoisomerase IIalpha (Topo IIalpha) was tested as a measure of cell proliferation in gliomas. Immunostaining for the Topo IIalpha and for the Ki-67 antigen (MIB-1 antibody) was performed in paraffin-embedded tissue sections obtained from 25 resected human gliomas. Additionally, cultured human glioma cells were subjected to simultaneous flow cytometry to determine Topo IIalpha and DNA content. Using flow cytometric analysis, the authors found that the Topo IIalpha antibody labeled cells in the S, G2, and M phases of the cell cycle and also those in some parts of the G0 and G1 phases. In histological sections, Topo IIalpha showed more distinct staining than MIB-1, particularly in older archival cases. The proliferative indices (PIs) based on cells staining for MIB-1 and Topo IIalpha correlated highly with one another (r = 0.96). The Topo IIalpha PI immunopositivity was seen in 4.07% of cells in the low-grade astrocytoma group, 11.97% in the anaplastic astrocytoma group, and 13.84% in the glioblastoma multiforme group, representing significant differences between low-grade astrocytoma and both anaplastic astrocytoma and glioblastoma. A Topo IIalpha PI less than 5% predicted longer patient survival (p = 0.003). Immunostaining for Topo IIalpha represents a useful alternative to MIB-1 as a proliferative index in human gliomas.

Radical surgery and reoperation in supratentorial malignant glial tumors.

The treatment modalities for gliomas are still questioning and searching. We reviewed the effect of the extent of surgical resection and reoperation on the length and quality of survival in 152 consecutive patients who underwent operation for supratentorial gliomas at GATA Neurosurgery clinic between 1985 to 1995. Seventy-two patients (50%) had glioblastoma multiforme (GBM), and 48 patients (33%) had anaplastic astrocytoma (AA). Gross total resection was achieved in 70 cases (49%), subtotal resection was performed in 60 cases (42%), and biopsy was carried out in 14 cases (9%). Thirty-two patients were reoperated for recurrency and the median interval between the first operation and reoperation was 9.5 months in glioblastoma multiforme, and 11.7 months in anaplastic astrocytoma. The resection groups were compared for age, sex, preoperative and postoperative Karnofsky rating, tumor location, postoperative radiation therapy, and chemotherapy, and survival according to multivariate analysis. Preoperative Karnofsky rating and surgical resection type were the most important factors related to survival after operation or reoperation. The gross total resection group lived longer than the subtotal resection group by life table analysis. Median survival of GBM was 76 weeks in gross total resection group, and 33 months in AA group with total resection (p < 0.001). Preoperative Karnofsky scores had a statistically significant effect on the quality of life and survival after operation and reoperation in all cases (p = 0.005). Radical surgery and reoperation also improve quality and length of life in selective malignant supratentorial gliomas.

Intra-Arterial Chemotherapy with Carboplatin (CBDCA) and Vepesid (VP16) in Primary Malignant Brain Tumours

Twenty three patients (18 males) were followed from January 1993 to July 1996 for primary central nervous system malignancy: glioblastoma multiforme (GM) (15 patients), anaplastic astrocytoma (AA) (8 patients). Ninety one cycles (average 4 cycles per patient) of intraarterial chemotherapy (IACH) were administered. The IACH included: Carboplatin (CBP) 250 mg/m2 and Vepesid (VPI6) 150 mg/m2 infusion; both drugs in normal saline, 100 ml and 250 ml, were infused over 15 and 30 min respectively. IACH was repeated every two weeks four or six times according to response to chemotherapy. IACH was preceded by i.v. methylprednisolone 40mg and pure anti-emetic (5HT3 serotonin uptake inhibitors) and subcutaneous daily doses of G-CSF following IACH to prevent neutropenia. The whole treatment required a 24h hospital admission. The IACH was well-tolerated and toxicity (Miller's grade, WHO) included: two cases ofreversible pulmonary embolism (8.6%) three and ten days respectively after therapy (one patient had atrial fibrillation, two cases grade 2 vomiting, two grade 1 anaemia and three grade 3 thombocytopenia (13%). Response to therapy was evaluated in 21 out of 23 patients, two having not yet received at least four IACH cycles: 4 PRO (3 GM, 1 AA), 15 SD (10 GM, 5 AA) and 2 PR (AA). Seventeen patients responded to IACH (SD + RO) (74%), and the P Rs belonged to the AA group. Survival duration was from 16 + to 108 weeks. IACH with CP and VP16 warrants further studies focussing on drug dose and schedule. A prospective randomized multicentric trial evaluating radiotherapy and systemic chemotherapy plus/minus IACH is currently underway.

“Instant-mix” whole brain photon with neutron boost radiotherapy for malignant gliomas

From July 1985 through March 1987, 44 consecutive patients with supratentorial, nonmetastatic anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM) were treated with whole brain photon irradiation with concomittant neutron boost at the University of Chicago. All patients had biopsy proven disease and surgery ranged from biopsy to total gross excision. Whole brain photon radiation was given at 1.5 Gy per fraction, 5 days weekly for a total dose of 45 Gy in 6 weeks. Neutron boost radiation was prescribed to a target minimum dose that included the pre-surgical CT tumor volume plus 1 cm margin. Neutrons were administered 5–20 minutes prior to photon radiation twice weekly and a total dose of 5.2 Gy nγ was administered over 6 weeks. Median follow-up was 36 months. The median survival was 40.3 months for anaplastic astrocytoma (10 patients) and 11 months for glioblastoma multiforme (34 patients) and 12 months for the overall group. Variables that predicted longer median survival included histology (AA vs. GBM), age (⩽39 years vs. older), and extent of surgery (total gross or partial excision vs. biopsy) whereas tumor size and Karnofsky performance status did not have a significant influence. The median survival of the anaplastic astrocytoma group was better than expected compared to the RTOG 80-07 study (a dose-finding study of similar design to this study) and historical data. Reasons for this are discussed.