High dose chemotherapy with autologous bone marrow rescue for children with diffuse pontine brain stem tumors. Children's Cancer Group

Radiation therapy and high-dose tamoxifen in the treatment of patients with diffuse brainstem gliomas: results of a Brazilian cooperative study. Brainstem Glioma Cooperative Group

PURPOSE

The efficacy of radiation therapy (RT) combined with tamoxifen (TX) was tested in patients diagnosed with diffuse brainstem gliomas in a multicenter trial.

PATIENTS AND METHODS

TX was administered orally (maintenance dose: 200 mg/m(2) per day) along with conventional local RT and then continued for 52 additional weeks. Survival, tumoral radiologic response, and toxicity were evaluated. Compliance was assessed using pharmacokinetic measurements.

RESULTS

Of 29 patients, 27 completed RT (median dose, 54 Gy). Of 22 assessable patients, 11 (50%) had an objective radiologic response. The mean TX steady-state serum level was 2.44 micromol/L +/- 1.02 micromol/L. Only three patients completed the entire course of treatment without tumoral progression or significant toxicity. Common side effects included nausea and vomiting. Hepatotoxicity (five patients), neurotoxicity (two patients), venous thrombosis (one patient), bilateral ovarian cysts (two patients), and transient neutropenia (one patient) were also observed. Median survival was 10.3 months. Only four patients remain alive without tumoral progression. The 1-year survival rate (mean +/- SD) was 37.0% +/- 9.5%.

CONCLUSION

This treatment combination produced no significant change in the overall poor prognosis of these patients. Most tumors responded initially to treatment but recurred as the study progressed. A minority of patients seemed to benefit from the extended use of TX. Generally, treatment was well tolerated, with good patient compliance, but we recommend continuous close monitoring for side effects. Based on our poor results, we recommend that alternative treatments be tested in patients with this type of tumor.

Radiotherapy followed by high dose busulfan and thiotepa: a prospective assessment of high dose chemotherapy in children with diffuse pontine gliomas

BACKGROUND

The role of high dose chemotherapy (HDC) in patients with pediatric brain tumors currently is ill-defined. The purpose of this pilot study was to assess the feasibility and the benefit of HDC after radiotherapy in a group of children with newly diagnosed diffuse pontine gliomas.

METHODS

Patients eligible for study were ages 3-18 years with diffuse intrinsic tumors arising in the pons, who were not treated previously with radiotherapy or chemotherapy. Histologic confirmation was not mandatory, provided clinical findings and magnetic resonance imaging were typical. Patients were given focal radiotherapy followed 2-3 months later by HDC. Busulfan (150 mg/m(2) on Days 8, 7, 6, and 5) and thiotepa (300 mg/m(2) on Days 4, 3, and 2) were administered prior to autologous bone marrow transplantation. Survival was the endpoint, and the statistical procedure was based on sequential subgroup analysis.

RESULTS

Thirty-six patients were entered on to the study, 12 of whom underwent stereotactic biopsy or open surgery at the time of diagnosis. One patient eventually was excluded due to inappropriate eligibility criteria. All 35 eligible patients received irradiation. Early progression (9 patients) and parental refusal (2 patients) precluded the use of HDC in 11 patients. Three patients died of HDC-related complications. All 21 patients who survived HDC eventually died of disease progression. The median survival time was 10 months for the study group. The median survival time in the subgroup of patients who received HDC was 10 months (range, 3-26 months). Statistical analysis did not suggest any evidence of survival benefit.

CONCLUSIONS

For patients with diffuse pontine gliomas, survival using this aggressive treatment modality does not appear to be any better than that reported for conventional radiotherapy.

The role of high-dose chemotherapy and stem cell rescue in the treatment of malignant brain tumors: a reappraisal

The outcome for children with malignant brain tumors has improved modestly in recent years. Notable is the improved 5-yr disease-free survival for those children with 'standard-risk' medulloblastoma and other primitive neuro-ectodermal tumors (PNET) (i.e. tumors without neuraxis dissemination at presentation). For other children with newly diagnosed malignant brain tumors, especially in the absence of radical surgical resection, the outcome remains poor despite surgery, irradiation and conventional chemotherapy. Patients whose tumors recur despite initial therapy continue to experience a dismal outlook with these conventional strategies of treatment. In an attempt to improve the outlook for such brain tumor patients with poor prognoses, strategies utilizing high-dose (potentially myeloablative) chemotherapy with autologous stem cell rescue have been developed. These studies, conducted initially in patients with recurrent tumors, were then extended to patients with newly diagnosed malignant gliomas and brain-stem tumors, as well as to young children with various malignant brain tumors at diagnosis in an attempt to avoid irradiation to the brain. The results of several of these studies are summarized, updating information reviewed in an earlier summary in 1996, demonstrating durable disease-free survival for a proportion of patients with recurrent malignant gliomas and medulloblastomas/PNET, as well as encouraging data in some of those patients with newly diagnosed brain tumors.

Globular glioma of the tectum

Brainstem gliomas are a heterogeneous group of tumors whose prognosis and treatment depend not only on the histologic features but also on the location within the brainstem. Magnetic resonance imaging allows the recognition of a distinct type of brainstem glioma of the tectal region of the midbrain, leading to aqueductal compression and hydrocephalus. The radiologic appearance of these tumors is usually rather uniform, with a characteristic nonenhancing thickening of the tectal plate. Because of its protracted course, no further treatment is necessary beyond cerebrospinal fluid diversion and close clinicoradiologic follow-up. The authors report two children with tectal plate gliomas of unusual but strikingly similar appearance. They present a clinical picture suggestive of intracranial hypertension without localizing signs. Magnetic resonance images reveal hydrocephalus related to the presence of perfectly circular lesions, hypointense on T1 and hyperintense on T2, which could be mistaken for parasitic cysts or represent dilated rostral portions of the sylvian aqueduct. After the cerebrospinal fluid diversion procedures, no further treatment was given, with one of the patients being monitored for 10 years and the other for 8 months, without tumor progression. These patients demonstrate that tectal gliomas, despite sharing a good prognosis, may have various patterns of growth, leading to unusual radiologic appearances that may pose diagnostic difficulties.

Innovative therapies for pediatric brain tumors

Success in the treatment of pediatric brain tumors has lagged behind that of other pediatric cancers. This paper highlights many of the advances that have taken place over the past few years in the surgical, radiotherapeutic, and chemotherapeutic approaches to central nervous system lesions that we hope will lead to a dramatic improvement in outcome. Innovations in neurosurgical and radiotherapeutic techniques have resulted in decreasing toxicity although substantial improvement in cure rates has not been observed. Many new techniques such as gene therapy, angiogenesis inhibitors, immunotherapy, and others that have not been part of the classic approach to these lesions are now in clinical trials in the hope that they will impact on the survival of these patients. The scientific basis for these new treatment modalities and preliminary clinical results are discussed.