Multidisciplinary management of adult anaplastic astrocytomas

Temozolomide: The evidence for its therapeutic efficacy in malignant astrocytomas

Introduction:

Malignant gliomas are a heterogeneous group of primary central nervous system neoplasms that represent less than 2% of all cancers yet carry a significant burden to society. They are frequently associated with considerable and progressive neurological disability and are ultimately intractable to all forms of treatment. Temozolomide (TMZ) is a new second generation DNA alkylating agent that has become part of malignant astrocytoma management paradigms because of its proven efficacy, ease of administration, and favorable toxicity profile.

Aims:

To review the role of TMZ in the management of malignant astrocytomas (World Health Organization grades III and IV) including newly diagnosed (n) and recurrent (r) anaplastic astrocytomas (AA) and glioblastomas.

Evidence review:

A series of pivotal clinical trials have established a role for TMZ in the treatment of malignant astrocytomas. A large phase II trial examining the role of TMZ in rAA showed a response rate of 35%, and a 6-month progression-free survival of 46%. This led to the accelerated approval of TMZ by the FDA and the EU for the treatment of rAA. Evidence for a role of TMZ in nAA is currently limited but research is ongoing in this area. The role of TMZ in the management of glioblastoma at the time of recurrence (rGBM) is less impressive but evidence for its activity was demonstrated in two large phase II trials that led to the approval of TMZ for this indication in Europe and Canada but not in the US. A recent large prospective randomized phase III trial showed that the addition of TMZ during and after radiation therapy (RT) in newly diagnosed (nGBM) patients prolonged median overall survival by 2.5 months; perhaps more importantly, the 2-year survival rate for patients receiving TMZ and RT was 26% compared with 10% for those receiving RT alone. Concurrent TMZ with RT followed by adjuvant TMZ has become the standard of care for nGBM patients. Based on the evidence presented in this trial, TMZ received approval from the FDA and the EU for patients with nGBM in 2005.

Place in therapy:

There is evidence to support the use of TMZ for the following diseases in the order of most to least convincing: nGBM, rAA, rGBM, and nAA. This order may quickly change as more trials are being designed and implemented, particularly with novel TMZ dosing schedules.

Tinzaparin prophylaxis against venous thromboembolic complications in brain tumor patients

The purpose of this study was to determine the safety of tinzaparin for deep vein thrombosis prophylaxis in newly diagnosed grade III-IV malignant glioma patients. Patients were initiated on daily tinzaparin at a fixed dose of 4,500 IU subcutaneously between 48 h and 4 weeks post-operative for planned duration of 12 months. During chemotherapy cycles, blood counts were monitored weekly and tinzaparin was held if the platelet count decreased to <50,000 and was re-initiated at a platelet count >100,000. Forty patients were enrolled into the study, 35 with glioblastoma multiforme and 5 with anaplastic astrocytoma. Possible attributable toxicity was limited to two patients who developed CNS hemorrhages (one grade 1 and one grade 2) and one patient with an increase in liver enzymes (grade 3). There were no patients with a grade 4 or 5 CNS hemorrhages or systemic hemorrhages >or=grade 2. The median time on prophylactic tinzaparin was 161 days (range of 5 to 601 days). One patient developed a deep venous thrombosis while taking tinzaparin, and three patients developed thromboembolic complications while off tinzaparin. Tinzaparin at a fixed prophylactic dose is safe and may decrease the incidence of thromboembolic complications in brain tumor patients.

Multicentric anaplastic astrocytoma in a child

We report a rare case of anaplastic astrocytoma with multicentric central nervous system lesions in a 10-year-old girl presenting with a 1-month history of progressive headache and paraparesis. Neurological examination upon admission revealed papilloedema of both eyes and grade 2/5 weakness of both legs. Cranial and spinal magnetic resonance imaging revealed multiple tumour foci within the suprasellar region, cerebellar hemisphere, cervical and thoracic cords. After an uneventful laminectomy and excision of the tumour at the T8-9 level, a significant improvement of motor function was observed. The histological diagnosis was anaplastic astrocytoma based on the WHO classification. The patient received postoperative radiotherapy and chemotherapy, and was able to walk with the aid of auxiliary crutches. Despite being an uncommon disease in children and being associated with an unfavourable long-term outcome, early diagnosis and appropriate management of this condition may contribute to reduced patient morbidity.

Phase I study pilot arms of radiotherapy and carmustine with temozolomide for anaplastic astrocytoma (Radiation Therapy Oncology Group 9813): implications for studies testing initial treatment of brain tumors

PURPOSE

To determine the safety and toxicity of carmustine (BCNU) and temozolomide (TMZ) with radiotherapy (RT) in newly diagnosed anaplastic astrocytoma.

METHODS AND MATERIALS

Patients >18 years old with anaplastic astrocytoma, a Karnofsky performance status score of > or =60, and adequate pulmonary function were eligible. All patients provided informed consent. Standard RT started within 5 weeks of diagnosis. In both arms, 150 mg/m(2) of TMZ was given on Days 1-5 of RT. In Arm 1, 200 mg/m(2) of carmustine was given on Day 1 of RT. In Arm 2, 150 mg/m(2) of carmustine was given on Day 5 of RT. After RT, TMZ and carmustine were repeated for a total of six cycles.

RESULTS

A total of 15 and 14 patients were enrolled in the two pilot arms. Because of hematologic and pulmonary toxicities, dose reductions by the second cycle of therapy occurred in >70% of the patients in Arm 1 and >50% in Arm 2 despite a reduction in the carmustine dose.

CONCLUSION

The results of these pilot studies have implications for the design of studies testing the initial treatment of brain tumors. Because of the poor tolerance of the combination, the multicooperative group Phase III study consists of two randomized arms of single-agent carmustine vs. single-agent TMZ.

Phase II study of neoadjuvant 1, 3-bis (2-chloroethyl)-1-nitrosourea and temozolomide for newly diagnosed anaplastic glioma

BACKGROUND

Temozolomide (TMZ) and 1, 3-bis (2-chloroethyl)-1-nitrosourea (BCNU) are reported to be active agents in anaplastic glioma (AG). TMZ has also been shown to deplete alkyltransferase, a DNA repair enzyme that contributes to nitrosourea resistance. The objective of the current study was to determine the efficacy and toxicity profile of a combination of these agents before radiotherapy in newly diagnosed AG.

METHODS

Eligibility criteria included histologically confirmed newly diagnosed AG with measurable enhancing disease, a Karnofsky performance score (KPS) > or = 60, normal pulmonary function, and normal laboratory parameters. In addition, informed consent was obtained from all patients. BCNU given at a dose of 150 mg/m(2) intravenously was followed after 2 hours by TMZ given at a dose of 550 mg/m(2) orally on Day 1 of a 42-day cycle to a maximum of 4 cycles, unless there was tumor progression or unacceptable toxicity.

RESULTS

Forty-one eligible patients were accrued. Their median age was 40 years. Seventy-six percent of patients had a KPS of 90-100. The histology was 81% anaplastic astrocytoma, 12% anaplastic oligodendroglioma, and 7% mixed tumors. Twenty-two percent of patients did not complete 4 cycles because of toxicity, mainly hematologic. Forty-six percent of patients experienced Grade 3 or 4 (according to National Cancer Institute Common Toxicity Criteria) thrombocytopenia. Twenty percent had Grade 4 granulocytopenia. Two patients died while receiving therapy, 1 of progressive disease and the other of Pneumocystis carinii pneumonia. The complete and partial response rates were 2% and 27% respectively. An additional 54% of patients had stable disease. Seventeen percent developed progressive disease (10% after the first cycle and 7% after the second cycle).

CONCLUSIONS

This neoadjuvant strategy was associated with significant myelosuppression and a modest response rate in patients with newly diagnosed AG.

Radioiodinated (I-125) monoclonal antibody 425 in the treatment of high grade glioma patients: ten-year synopsis of a novel treatment

The present report is the follow-up of patients enrolled in a phase II clinical trial using I-MAb 425 as an adjuvant treatment for high grade gliomas. Patient median survivals support published data from an earlier preliminary report. From January 29, 1987 to January 25, 1997, 180 patients diagnosed with astrocytoma with anaplastic foci (AAF) and glioblastoma multiforme (GBM) were treated as outpatients with an average of three weekly intravenous or intraarterial injections of radiolabeled MAb 425. The mean dose was 140 mCi (5.2 GBq). Only one patient who received a single dose of more than 60 mCi (2.2 GBq) experienced acute toxicity. Patients received prior surgery and radiation therapy, with and without chemotherapy. Overall median survival for patients with GBM and AAF was 13.4 and 50.9 months, respectively, with Karnofsky Performance Status (KPS) ranging from 40 to 100 and age ranging from 11 to 75 years. Prognostic factors (KPS and age) correlated positively with increased survival, with KPS the most important determinant of median survival. Data analysis was performed on patients followed 5 years or longer. We conclude that the administration of I-MAb 425 with intensive medical management demonstrates a significant increase in median survival and should be considered a therapeutic regimen for the management of patients with high grade gliomas.