Prolonged response to carboplatin in an infant with brain stem glioma

Vincristine and carboplatin chemotherapy for unresectable and/or recurrent low-grade astrocytoma of the brainstem

BACKGROUND

Radiotherapy remains a widely accepted postoperative treatment modality for unresectable or recurrent low-grade glioma (LGG). However, there is increasing evidence to suggest that chemotherapy can delay and may obviate the need for radiotherapy in progressive/recurrent LGG. The majority of the published experience is in children with hypothalamic/optic chiasmatic lesions and little information is available regarding its use in LGG of the brainstem.

PROCEDURE

We describe clinical characteristics and course of children with LGG of the brainstem who received carboplatin-based chemotherapy in two institutions over 10 years (1996-2006). This was a retrospective review of consecutively treated children with LGG of the brainstem (midbrain, pons, medulla, and upper cervical cord). Vincristine and carboplatin were first-line chemotherapy regimen used in all patients.

RESULTS

In this series, there were 16 children (9 males) with median age at diagnosis of 4.2 years (range 0.5-8). Eight children were treated at diagnosis while the remaining eight received chemotherapy after either radiological progression or clinical deterioration. After a median follow-up of 57 months (range 20-136) from initiation of chemotherapy all children are alive and 11 remain progression free (1 complete response, 8 with partial response + minor response, and 2 stable diseases).

CONCLUSIONS

The efficacy of this chemotherapy regimen in this series supports its role in children with progressive unresectable LGG of brainstem.

Visual improvement despite radiologically stable disease after treatment with carboplatin in children with progressive low-grade optic/thalamic gliomas

BACKGROUND

The purpose of this study was to examine the clinical and radiologic response to carboplatin by children with progressive optic/thalamic gliomas.

PATIENTS AND METHODS

Between July 1997 and July 1999, 12 consecutive children were treated with monthly carboplatin for progressive optic/thalamic gliomas.

RESULTS

Five children have completed 12 cycles of carboplatin and five children are currently receiving treatment. Two children had progressive disease noted both clinically and radiologically. Nine children have stable radiologic disease and one child has had a partial radiologic response to chemotherapy. Eight children have had regular visual assessments. Four children (three with stable radiology and one with a partial radiologic response) have had improvement in their vision. Three children with radiologically stable disease have had no change in vision. One child has had deterioration in vision despite radiologically stable disease.

CONCLUSIONS

The results suggest that the clinical response of optic/thalamic gliomas to carboplatin, as measured by visual acuity and visual fields, may be better than predicted by radiologic assessment. These data suggest that a prospective clinical study is warranted of the role of carboplatin in children with progressive optic/thalamic gliomas and visual impairment.

A phase I/II study of carboplatin combined with hyperfractionated radiotherapy for brainstem gliomas

BACKGROUND

Brainstem gliomas often respond to radiotherapy but long term disease control is exceptional. The concomitant administration of a chemotherapy agent with radiosensitizing properties such as carboplatin may increase the efficacy of radiotherapy.

METHODS

A dose escalation schedule of carboplatin was devised to determine the maximum tolerated dose (MTD) of intravenous carboplatin when given on a twice-weekly schedule during a course of hyperfractionated, involved field radiotherapy (100 centigrays [cGy] twice daily to 7200 cGy). The starting dose was 20 mg/m(2) and the dose was increased by 15 mg/m(2) after every 3 patients provided no Grade 3 or 4 (according to the National Institutes of Health Common Toxicity Criteria) toxicity occurred. Magnetic resonance imaging (MRI) scans (brain and spine) were obtained before treatment and at the time of disease progression. Clinical entry criteria included an MRI scan demonstrating a diffuse intrinsic pontine tumor and a typical 2-3-month history of evolving cranial neuropathies and a gait disorder. Biopsy-confirmed evidence of a high grade glioma was required for nonpontine brain stem tumors.

RESULTS

A total of 34 patients were enrolled. The median age of the patients was 7.8 years (range, 3.6-15.4 years) and the median prodrome duration was 1.5 months (range, 0.25-36 months). The MTD was 110 mg/m(2) or a total cumulative dose of 1540 mg/m(2) over 7 weeks. The dose-limiting toxicity was hematologic. The median progression free survival was 8 months (range, 0-104+ months) and the overall survival was 12 months (range, 5-104+ months). At last follow-up there were 5 long term survivors (15%) who remained in continuous remission after a mean follow-up period of 79 months (range, 46-104 months). Fifteen of the 29 patients (52%) with recurrence and or disease progression developed leptomeningeal/intraaxial tumor spread beyond the local radiation field.

CONCLUSIONS

The cumulative MTD for carboplatin is 1540 mg/m(2) when administered concomitantly with involved field, hyperfractionated radiotherapy in a twice-weekly schedule for 7 weeks. Subsequent Phase II and III clinical trials can be conducted safely at this level.

Carboplatin and etoposide with hyperfractionated radiotherapy in children with newly diagnosed diffuse pontine gliomas: a phase I/II study

BACKGROUND

Diffuse pontine gliomas remain one of the most lethal of pediatric malignancies despite the use of increasingly intensive therapies. We delivered intensive chemotherapy during and following 70.2 Gy of hyperfractionated radiation therapy in an attempt to improve survival.

PROCEDURE

Nine consecutive children with diffuse pontine gliomas were treated on this single arm study. Carboplatin, given in combination with fixed dose etoposide, was escalated in successive cohorts to determine its maximum tolerated systemic exposure (AUC). Outcome was coded based on imaging characteristics and clinical status.

RESULTS

Eight of the nine children on this study died of their disease at a median of 44 weeks, essentially the same survival as those treated on a previous Pediatric Oncology Group study using hyperfractionated radiation therapy alone. Toxicity was almost exclusively hematologic and not associated with significant morbidity.

CONCLUSIONS

The use of concurrent carboplatin and etoposide with hyperfractionated radiation therapy did not appear to improve the survival in this group of children with diffuse pontine gliomas. The toxicity of this chemotherapy during radiation therapy was primarily hematologic and well tolerated. New approaches to the treatment of these tumors need to be investigated.

Does chemotherapy have a role in low-grade astrocytoma management? A report of 13 cases

Surgery is the treatment of choice for low-grade astrocytoma while radiotherapy is carried out only when total resection is not possible. This study assessed the effectiveness of chemotherapy in nonresectable cases. Thirteen children with nonresectable astrocytoma were treated with carboplatin and etoposide and after four cycles the response to treatment was evaluated according to radiologic criteria. The results were: one with complete response (CR), three with minor response (MR), six with stable disease (SD), and three with progressive disease (PD). Moreover, in 77% there was an improvement in the neurologic picture. In particular, two cases with hypothalamic astrocytoma showed a regression of the diencephalic syndrome following chemotherapy. In six cases chemotherapy was carried out, at reduced dosage, after the first four cycles either because there was clinical improvement or because it was necessary to postpone radiotherapy in very young patients. After a follow-up period ranging between 11 and 63 months (average: 30 months), nine of the 13 patients are alive (69%) while four died of disease progression. Further studies would be useful to evaluate the role of chemotherapy in the management of low-grade astrocytoma.

Multidrug resistance gene (MDR 1) expression in neuro-axial tumours of children and young adults

Drug resistance in many cancers outside the CNS has been associated with over-expression of the multidrug resistance gene (MDR1), which codes for the transmembrane efflux pump P-glycoprotein (Pgp). To determine whether tumours of the neuroaxis over-express MDR1 and to identify the site of Pgp expression we examined 50 tumour specimens from 46 children and young adults using immunocytochemistry. Pgp was not expressed by any neoplastic cells, but was detected in the endothelium of tumour blood vessels in 35 of the 50 samples (70%). 11/35 (31%) were Pgp positive in the majority of vessels, 11/35 (31%) in a proportion, but < 50% of vessels, and 13/35 (37%) in one or two vessels. Pgp was also detected in surrounding normal brain capillaries. MDR1 may play a role in the chemoresistance of neuro-axial tumours either by its expression in the normal blood-brain barrier or by forming a blood-tumour barrier. The proportion of vessels expressing Pgp may determine the degree of resistance.

Intra-arterial chemotherapy for brain stem glioma: report of four cases

Four patients with pontine gliomas were treated with radiation and intra-arterial chemotherapy using ACNU, cisplatin, and/or carboplatin. All underwent biopsy and were histologically proven to have gliomas. Even though three were benign histologically, all appeared malignant on neuroimaging. Two patients had complete remissions; the others had partial responses; three patients died, 36, 14, and 15 months after the primary diagnosis. One patient, now in complete remission, has been alive for 24 months. There was no neurotoxicity except for transient nausea and vomiting. Intra-arterial chemotherapy is effective against brain stem gliomas, producing remission with minimum side effects.

Brainstem glioma: I. Pathology, clinical features, and therapy

Gliomas that arise in the brain stem have been associated with a poor prognosis. Diagnostic neuroimaging readily identifies the tumor as it extends between normal brainstem structures. Histologic sampling of tumor with stereotactic methods is notoriously unreliable in establishing a definitive prognosis. Clinical trials that incorporate high-dose chemotherapy, autologous bone marrow rescue, and irradiation hold promise of better tumor control by overcoming the inaccessibility of the central nervous system to standard doses of chemotherapy. We review the pathology, clinical features, neuroimaging features, and current therapeutic concepts relative to brainstem glioma. The pediatric neurologist has a pivotal role in identifying and monitoring children with this malignancy.