Preradiation chemotherapy in primary high-risk brainstem tumors: phase II study CCG-9941 of the Children's Cancer Group

Concurrent radiotherapy with temozolomide followed by adjuvant temozolomide and cis-retinoic acid in children with diffuse intrinsic pontine glioma

The prognosis of children with diffuse intrinsic pontine glioma (DIPG) is very poor. Radiotherapy remains the standard treatment for these patients, but the median survival time is only 9 months. Currently, the use of concurrent radiotherapy with temozolomide (TMZ) has become the standard care for adult patients with malignant gliomas. We therefore investigated this approach in 12 children diagnosed with DIPG. The treatment protocol consisted of concurrent radiotherapy at a dose of 55.8-59.4 Gy at the tumor site with TMZ (75 mg/m(2)/day) for 6 weeks followed by TMZ (200 mg/m(2)/day) for 5 days with cis-retinoic acid (100 mg/m(2)/day) for 21 days with a 28-day cycle after concurrent radiotherapy. Ten of the 12 patients had a clinical response after the completion of concurrent radiotherapy. Seven patients had a partial response, four had stable disease, and one had progressive disease. At the time of the report, 9 of the 12 patients had died of tumor progression, one patient was alive with tumor progression, and two patients were alive with continuous partial response and clinical improvement. The median time to progression was 10.2 +/- 3.0 months (95% confidence interval [CI], 4.2-16.1 months). One-year progression-free survival was 41.7% +/- 14.2%. The median survival time was 13.5 +/- 3.6 months (95% CI, 6.4-20.5 months). One-year overall survival was 58% +/- 14.2%. The patients who had a partial response after completion of concurrent radiotherapy had a longer survival time (p = 0.036) than did the other patients (those with stable or progressive disease). We conclude that the regimen of concurrent radiotherapy and TMZ should be considered for further investigation in a larger series of patients.

Identification of interleukin-13 receptor alpha2 chain overexpression in situ in high-grade diffusely infiltrative pediatric brainstem glioma

Human malignant glioma cell lines and adult brain tumors overexpress high levels of interleukin-13 receptor alpha2 chain (IL-13Ralpha2). Because the IL-13Ralpha2 chain is an important target for cancer therapy and prognosis for patients with brainstem glioma (BSG) remains dismal, we investigated the expression of this receptor in specimens of diffusely infiltrative pediatric BSG relative to normal brain tissue. Twenty-eight BSG specimens and 15 normal brain specimens were investigated for IL-13Ralpha2 protein expression by immunohistochemical analysis (IHC) using two different antibodies in two different laboratories. Highly sensitive Q-dot-based IHC and in situ hybridization (ISH) assays were also developed to identify IL-13Ralpha2 protein and RNA in these specimens. The results were evaluated independently in two laboratories in a blinded fashion. By Q-dot IHC or a standard IHC assay, 17 of 28 (61%) tumor specimens showed modest to strong staining for IL-13Ralpha2, while 15 normal brain tissue samples showed weak expression for IL-13Ralpha2 protein. Significant interrater agreement between the two laboratories was seen in the assessment of IL-13Ralpha2 intensity. High-level IL-13Ralpha2 RNA expression was detected in tumor samples by Q-dot ISH, but only weak RNA expression was observed in normal brain. Significant agreement between ISH and IHC assays was observed (simple kappa [kappa] estimate=0.358, weighted kappa=0.89, p=0.001). IL-13Ralpha2 protein and mRNA are expressed to significantly higher levels in BSG than in normal brain tissue. Both IHC and ISH represent robust methods to detect expression of the IL-13Ralpha2 receptor in BSG that could represent an important new drug target for treatment of this disease.

Treatment of children with diffuse intrinsic brain stem glioma with radiotherapy, vincristine and oral VP-16: a Children's Oncology Group phase II study

BACKGROUND

The prognosis for children with brain stem glioma remains grim. Based on studies suggesting efficacy of vincristine and oral VP-16, The Pediatric Oncology Group (POG, now part of the Children's Oncology Group) conducted a study using these agents in combination with standard external beam radiation for children with newly diagnosed brain stem glioma.

METHODS

Children were eligible for the study if they 3-21 years of age, had MRI-evidence of a diffuse intrinsic pontine glioma, and had neurologic deficits of <6 months duration. Patients received local radiotherapy to a dosage of 54 Gy. Chemotherapy consisted of two 28-day cycles of vincristine, 1.5 mg/m(2), days 1, 8, and 15 and oral VP-16, 50 mg/m(2), days 1-21, starting concurrent with radiation, and continuing for ten cycles following radiation.

RESULTS

Of the 31 children enrolled, 30 were eligible and evaluable for survival and toxicity. Their median age was 8 years (range 3-14 years). Seven patients (23%) had a partial response following radiation, 18 (60%) had stable disease, 2 (7%) had progressive disease, and response in 3 patients (10%) was not measured. All 30 children have died. Overall survival at 1 year was 27 +/- 7% and at 2 years, 3 +/- 2%. The median survival was 9 months (range 3-36 months). Hematologic toxicity was significant; other toxicities included constipation, mucositis, emesis, and infection.

CONCLUSION

The addition of vincristine and oral VP-16 to standard external beam radiation causes moderate toxicity and does not improve survival of children with diffuse intrinsic brain stem glioma.

Treatment of newly diagnosed diffuse brain stem gliomas in children: in search of the holy grail

Diffuse brain stem glioma is the most devastating of pediatric malignancies. Virtually all children with this disease die within 1-2 years of diagnosis. After three decades of exhaustive research, the key to controlling this malignancy still eludes us. Attempts to improve survival using radiation, chemotherapy and biologic agents have yet to culminate in meaningful advances. Recent advances in molecular biology have led to the development of more targeted therapies, which are now being introduced in clinical trials for children with brain stem glioma. As our understanding of the biology of this disease improves, so too will our ability to target it more effectively. Real strides in improving the lives of children with brain stem glioma may finally be within our grasp.

Phase I trial of imatinib in children with newly diagnosed brainstem and recurrent malignant gliomas: a Pediatric Brain Tumor Consortium report

This study estimated the maximum tolerated dose (MTD) of imatinib with irradiation in children with newly diagnosed brainstem gliomas, and those with recurrent malignant intracranial gliomas, stratified according to use of enzyme-inducing anticonvulsant drugs (EIACDs). In the brainstem glioma stratum, imatinib was initially administered twice daily during irradiation, but because of possible association with intratumoral hemorrhage (ITH) was subsequently started two weeks after irradiation. The protocol was also amended to exclude children with prior hemorrhage. Twenty-four evaluable patients received therapy before the amendment, and three of six with a brainstem tumor experienced dose-limiting toxicity (DLT): one had asymptomatic ITH, one had grade 4 neutropenia and, one had renal insufficiency. None of 18 patients with recurrent glioma experienced DLT. After protocol amendment, 3 of 16 patients with brainstem glioma and 2 of 11 patients with recurrent glioma who were not receiving EIACDs experienced ITH DLTs, with three patients being symptomatic. In addition to the six patients with hemorrhages during the DLT monitoring period, 10 experienced ITH (eight patients were symptomatic) thereafter. The recommended phase II dose for brainstem gliomas was 265 mg/m(2). Three of 27 patients with brainstem gliomas with imaging before and after irradiation, prior to receiving imatinib, had new hemorrhage, excluding their receiving imatinib. The MTD for recurrent high-grade gliomas without EIACDs was 465 mg/m(2), but the MTD was not established with EIACDs, with no DLTs at 800 mg/m(2). In summary, recommended phase II imatinib doses were determined for children with newly diagnosed brainstem glioma and recurrent high-grade glioma who were not receiving EIACDs. Imatinib may increase the risk of ITH, although the incidence of spontaneous hemorrhages in brainstem glioma is sufficiently high that this should be considered in studies of agents in which hemorrhage is a concern.

Treatments for astrocytic tumors in children: current and emerging strategies

Strategies for the treatment of childhood cancer have changed considerably during the last 50 years and have led to dramatic improvements in long-term survival. Despite these accomplishments, CNS tumors remain the leading cause of death in pediatric oncology. Astrocytic tumors form the most common histologic group among childhood brain tumors. They are a heterogeneous group that from a practical therapeutic point of view can be subdivided into low-grade astrocytomas (LGA), optic pathway gliomas (OPG), high-grade astrocytomas (HGA), and brainstem gliomas (BSG). This article focuses on the practical application of treatments that lead to long-term survival, improved quality of life, and reduced long-term complications. Improvement in therapy has led to better outcomes for patients with LGA and OPG. Careful follow-up without any treatment is indicated for a small percentage of patients diagnosed with LGA with an indolent course including children with neurofibromatosis type 1 (NF1). Surgery is the main recommended treatment for children with resectable LGA. Radiation therapy is generally recommended for children with progressive LGA, or after failure of chemotherapy, accomplishing tumor control at 10 years in over 60% of patients. Cytotoxic chemotherapy is usually reserved for children who have had treatment failure with surgery and radiation therapy. It is also offered for children who are too young to be treated with radiation or to defer or avoid radiotherapy. Carboplatin and vincristine achieve 5% complete and 28% partial responses but the use of vincristine is criticized due to poor penetration of the CNS. A regimen of tioguanine, procarbazine, mitolactol, lomustine, and vincristine is frequently administered as an alternative to carboplatin and vincristine in LGA. The introduction of temozolomide has allowed better responses, including a 24% complete response rate compared with 0-5% complete response rates with the previous regimens. OPG are usually histologically LGA, and are treated with similar chemotherapy regimens. OPG is the most common type of brain tumor associated with NF1. Tumor growth in some of these patients is slow with no treatment recommended for an extended period of time. The prognosis for children with the remaining types of astrocytomas remains poor. Surgical resection is typically the first step in the treatment of HGA followed in older children by radiation therapy. The data regarding chemotherapy are mixed. Combination chemotherapy before or after radiation, including cisplatin, carmustine, cyclophosphamide, and vincristine or carboplatin, ifosfamide, cyclophosphamide, and etoposide has provided disappointing results. Clinical trials with temozolomide and agents directed against single targets have not shown substantially better results, but it is hoped that currently conducted studies will provide better outcomes. Diffuse intrinsic BSG are among the most difficult-to-treat brain tumors. Surgical treatment is not recommended for diffuse intrinsic BSG and standard radiation therapy is typically given in children aged >3 years. None of the numerous chemotherapy regimens, including temozolomide, has provided a significant response rate or an improvement in survival. It is expected that newer agents affecting multiple targets such as AEE-788 and antineoplastons, and combinations of single-targeted agents with chemotherapy will provide better results. Careful evaluation of histology, location of the tumor, patient age, and consideration of treatment-related morbidity play an important part in selecting between clinical observation, surgery, radiation, chemotherapy, or investigational agents. The goals of treatment for astrocytic tumors should extend well beyond objective responses and increased survival. Improvement of quality of life is an equally important objective of treatment. Radiation therapy and chemotherapy result in serious late toxicities.

Phase II study of thalidomide and radiation in children with newly diagnosed brain stem gliomas and glioblastoma multiforme

A phase II study was conducted to assess the efficacy of administering daily thalidomide concomitantly with radiation and continuing for up to 1 year following radiation in children with brain stem gliomas (BSG) or glioblastoma multiforme (GBM). Secondary objectives were to obtain preliminary evidence of biologic activity of thalidomide and to evaluate toxicities from chronic administration of thalidomide in this population. Thirteen patients (2-14 years old) with newly diagnosed BSG (12 patients) or GBM (one patient) were enrolled between July 1999 and June 2000. All patients received focal radiotherapy to a total dose of 5,580 cGy. Thalidomide was administered once daily beginning on the first day of radiation and continued for 12 months or until the patient came off study. The starting dose was 12 mg/kg (rounded down to the nearest 50 mg) and was increased by 20% weekly, if tolerated, to 24 mg/kg or 1,000 mg (whichever was lower). Advanced imaging techniques and urine and serum analysis for anti-angiogenic markers were performed in some patients in an attempt to correlate changes with clinical effect of therapy. No patients completed the planned 12 months of thalidomide therapy and all have since died of disease progression. The median duration of therapy was 5 months (range 2-11 months). Nine patients came off study for progressive disease (PD), three patients due to toxicity and one patient withdrew consent. Several patients on this study required more extended courses of high dose steroids than would have been otherwise expected for this population due to significant peritumoral edema and necrosis. No consistent pattern emerged from the biologic correlative studies from 11 patients. However, advanced imaging with techniques such as MR spectroscopy, MR perfusion and 18-fluorodeoxyglucose positron emission tomography (FDG-PET) were helpful in distinguishing growing tumor from treatment effect and necrosis in some patients. The median time to progression (TTP) was 5 months (range 2-11 months) and the median time to death (TTD) was 9 months (range 5-17 months). In this small patient sample adding thalidomide to radiation did not improve TTP or TTD from historical controls, however, toxicity appeared to be increased.

Diffuse brainstem glioma in children: critical review of clinical trials

Diffuse intrinsic brainstem gliomas constitute 15-20% of all CNS tumours in children, and are the main cause of death in children with brain tumours. Many clinical trials have been done over the past three decades, but survival has remained static. More than 90% of children die within 2 years of diagnosis, and conventional fractionated radiation remains the standard treatment. However, median survival differs substantially between clinical trials, suggesting a survival benefit with some strategies. We appraised the consistency between protocols in terms of eligibility criteria, definition and assessment of response and progression, statistical design, and endpoints. Study designs varied substantially, which could explain the differences in outcome, and no treatment has shown a benefit over conventional radiotherapy. However, consistency between protocols (eg, eligibility criteria and outcome measures) is important to measure the progress in management of diffuse pontine gliomas.

The treatment of high grade gliomas and diffuse intrinsic pontine tumors of childhood and adolescence: a historical - and futuristic - perspective

Pediatric high grade gliomas represent a heterogeneous group of tumors with poor prognoses despite the use of multimodal treatment. Very little progress has been made over the past decades in identifying efficacious therapeutic modalities against both high grade gliomas and diffuse brainstem gliomas in children. The degree of surgical resection is the most important clinical prognostic factor for children with high grade gliomas, and a complete resection should be attempted whenever feasible. The role of radiation therapy in the treatment of older children with high grade gliomas and diffuse brain stem gliomas is undisputed; however the benefit of using radiation for patients less than 6 years of age (with high grade gliomas) might be questionable. Despite the absence of solid evidence to support its use, chemotherapy is routinely used against these tumors. Currently temozolomide is being investigated due to its activity in adult trials and based on preliminary data regarding recurrent disease. A small subgroup of patients can be successfully treated with high dose chemotherapy followed by autologous stem cell rescue. Early trials using this modality in the past had been associated with high morbidity and mortality. High dose chemotherapy with autologous stem cell rescue in selected patients with minimal residual disease, angiogenesis inhibitors, radiosensitizers and other biological modifiers are being currently investigated in phase I/II trials.

Topotecan as a radiosensitizer in the treatment of children with malignant diffuse brainstem gliomas: results of a French Society of Paediatric Oncology Phase II Study

BACKGROUND

The current Phase II study was conducted to evaluate the survival and toxicity observed in children with newly diagnosed brainstem gliomas who were treated with the daily radiotherapy with topotecan used as a radiosensitizer.

METHODS

Eligible patients were those ages 3-18 years with previously untreated tumors arising in the pons diagnosed within the previous 6 months. Histologic confirmation was not mandatory provided that the clinical and magnetic resonance imaging findings were typical for a diffusely infiltrating brainstem lesion. Treatment was comprised of a 6-week course of topotecan administered intravenously at a dose of 0.4 mg/m(2)/day over 30 minutes within 1 hour before irradiation. Radiotherapy was comprised of a once-daily treatment of 1.8 grays (Gy) per fraction to a total dose of 54 Gy.

RESULTS

Thirty-two patients were included in the current study between August 2000 and October 2002. All patients completed the combined treatment in accordance with the treatment design. Only partial responses were observed, occurring in 40% of the patients. The 9-month and 12-month survival rates were 34.4% +/- 8% and 25.5% +/- 8%, respectively. The median duration of survival for these 32 patients was 8.3 months. An intratumoral cystic/necrotic change was observed in five patients, with clinical impairment noted in two patients. One intratumoral hemorrhage occurred during radiotherapy, and was associated with transitory neurologic impairment.

CONCLUSIONS

The findings of the current study regarding newly diagnosed brainstem glioma patients treated with topotecan given as a radiosensitizing agent did not reproduce the encouraging results obtained in preclinical studies. Therefore, the concomitant combination of topotecan and radiotherapy at this schedule and these doses cannot be recommended for the treatment of patients with brainstem gliomas.

Etoposide, vincristine, and cyclosporin A with standard-dose radiation therapy in newly diagnosed diffuse intrinsic brainstem gliomas: a pediatric oncology group phase I study

BACKGROUND

Brainstem gliomas (BSGs) are resistant to all therapy. Based on their imaging characteristics, we postulated that inhibition of P-glycoprotein (P-gp) associated with endothelial cells of the blood-brain barrier might enhance penetration of xenobiotic antineoplastics.

PROCEDURE

Seven patients were enrolled in a Phase I study of etoposide, continuous infusion cyclosporine A given with and escalating doses of vincristine and concomitant standard-dose irradiation.

RESULTS

Six patients were entered at the first level and one at the second. Closure of the study was mandated by dose-limiting neurotoxicity, consisting of seizures associated with white-matter changes, and alteration of consciousness with bulbar signs. One patient had tumor necrosis at 6 weeks, suggesting some tumor effect. Median survival for the group was 11 months, and for the patients who completed more than 1 month of therapy it was 11 months.

CONCLUSION

This regimen proved excessively toxic.

Brain Stem Tumors

Brain stem tumors are heterogeneous. They range from the diffuse pontine tumors, which are almost invariably fatal despite all known therapies, to lower-grade focal or exophytic tumors that often have a very good prognosis with surgery or observation only. In this article, we review the epidemiology of brain stem tumors and note that diffuse pontine tumors, although rare, are a significant contributor to mortality among pediatric oncology patients. Diagnosis in typical cases is made using a magnetic resonance imaging scan without biopsy. No highly effective standard treatment exists; therefore, inclusion of eligible patients in well-designed clinical research studies is extremely important. If an appropriate trial is not available, conventionally fractionated external beam radiation therapy can provide good short-term palliation to a significant proportion of patients. An important area of preclinical research that may soon be investigated in clinical trials for patients with diffuse pontine tumors is interstitial infusion of therapeutic agents, and the rationale for that approach is described in detail. Lastly, autopsy should be considered for patients who die of diffuse pontine tumors with the goal of obtaining tumor tissue for biological studies that may in the future lead to novel therapies.

Successful treatment of an unresectable choroid plexus carcinoma in a patient with Li-Fraumeni syndrome

Choroid plexus carcinoma (CPC) is an uncommon central nervous system tumor requiring complete surgical excision for favorable outcome. The authors report the successful treatment of a 2-year-old patient with widely disseminated CPC and Li-Fraumeni syndrome. Following a partial resection of the tumor the patient received chemotherapy consisting of cyclophosphamide, etoposide, and carboplatin. There were no additional surgical procedures and radiation was not administered. Remarkably, the patient remains without evidence of active disease more than 3 years from the completion of therapy. Additional studies are necessary to determine whether this treatment plan can be beneficial to other patients with CPC and whether the patient's p53 mutation had an effect on outcome.

Supratentorial high-grade astrocytoma and diffuse brainstem glioma: two challenges for the pediatric oncologist

Pediatric high-grade gliomas represent a heterogeneous group of tumors that accounts for 15%-20% of all pediatric central nervous system tumors. These neoplasms predominantly involve the supratentorial hemispheres or the pons, in which case the tumors are usually called diffuse brainstem gliomas. The diagnosis of supratentorial neoplasms is dependent on their histologic appearance. The maximum possible surgical resection is always attempted since the degree of surgical resection is the main prognostic factor for these patients. Older children (>3 years) with supratentorial neoplasms undergo a multimodality treatment comprised of surgical resection, radiation therapy, and chemotherapy. The addition of chemotherapy seems to improve the survival of a subset of these children, particularly those with glioblastoma multiforme. However, 2-year survival rates remain poor for children with supratentorial neoplasms, ranging from 10%-30%. The diagnosis of a diffuse brainstem glioma is based upon typical imaging, dispensing with the need for surgery in the majority of cases. Radiation therapy is the mainstay of treatment for children with diffuse brainstem gliomas. The role of chemotherapy for these children is not clear, and it is, in general, employed in the context of an investigational study. Less than 10% of children with diffuse brainstem gliomas survive 2 years. Because the outcome for patients with either type of tumor is poor when standard multimodality therapy is used, these children are ideal candidates for innovative treatment approaches.

Differential responsiveness among "high risk" pediatric brain tumors in a pilot study of dose-intensive induction chemotherapy

BACKGROUND

These factors have been predictive for progressive disease on therapy (PDOT) among pediatric brain tumors: >1.5 cm(2) unresectable tumor, glioblastoma, supratentorial primitive neuroectodermal tumor, and metastatic medulloblastoma (MBL). This pilot study sought to correlate cytoreductive response with progression free survival.

PROCEDURES

Four courses of cisplatinum, cyclophosphamide, etoposide, and vincristine preceded hyperfractionated radiotherapy (RT). Maintenance chemotherapy consisted of eight cycles of carboplatin, etoposide, and vincristine. Biopsy specimens were immunohistochemically studied for labeling index, hypoxia, and multidrug resistance proteins.

RESULTS

Twenty newly diagnosed patients [nine primitive neuroectodermal tumors/MBL, one choroid plexus carcinoma, eight malignant gliomas, and two anaplastic ependymomas] were treated. Ten patients, who required neuraxis irradiation, constituted the "PNET" group. These demonstrated five complete and one partial response (PR), with an estimated median progression free survival of 44 months and median survival in excess of 53 months. Patients treated with involved field irradiation were designated the "Glioma" group. Induction chemotherapy produced partial and minor responses (MRs) among 5/10. Their estimated median progression free survival was 6.9 months (P = 0.035 relative to the PNET) with a median survival of 10.7 months (P = 0.04). Age, labeling index, the presence of hypoxia, and Pgp/MDR1 expression failed to discriminate between the two groups.

CONCLUSIONS

This induction regimen produced a cytoreductive response in 6/10 and achieved a significant improvement in progression free survival among 7/10 in the PNET group. Unfortunately, responses among Glioma patients did not translate into durable control. Expression of the biologic factors was similar between both groups and did not correlate with diagnosis or response.

Gliomas del tronco encefálico

Brainstem gliomas have been increasingly understood in the last two decades and they are nowadays regarded as an heterogeneous group of tumors with tendency towards the pediatric age, where they account for 10-20% of brain neoplasms. Besides the well known diffuse tumor, several subtypes, with a different biological behaviour, amenable to surgical resection and better prognosis, have been identified, giving rise to many classifications and terms. In the other way, attention has been recently paid to adult brainstem gliomas in contrast to pediatric tumors. Based on a review of the literature, we describe the different subtypes of brainstem gliomas, with particular interest on therapeutic approaches and differences between pediatric and adult tumors, employing iconography from our series.

Phase II study of antineoplaston A10 and AS2-1 in patients with recurrent diffuse intrinsic brain stem glioma: a preliminary report

OBJECTIVE

A phase II study of antineoplaston A10 and AS2-1 was conducted to evaluate the antineoplastic activity in patients with recurrent diffuse intrinsic brain stem glioma.

PATIENTS AND METHODS

This report describes the results of treatment of the first 12 patients admitted to the study. Patients received escalating doses of antineoplaston A10 and AS2-1 by intravenous bolus injections. The median duration of treatment was 6 months and the average dosage of antineoplaston A10 was 11.3 g/kg/day and of antineoplaston AS2-1 0.4 g/kg/day. Responses were assessed by gadolinium-enhanced magnetic resonance imaging of the head.

RESULTS

Of ten evaluable patients, complete response was determined in two cases (20%), partial response in three (30%), stable disease in three (30%) and progressive disease in two (20%). Survival at 2 years was 33.3%. Currently, of all 12 patients, two (17%) were alive and tumour free for over 5 years since initial diagnosis; one was alive for more than 5 years, and another for more than 4 years from the start of treatment. Only mild and moderate toxicities were observed, which included three cases of skin allergy, two cases of anaemia, fever and hypernatraemia, and single cases of agranulocytosis, hypoglycaemia, numbness, tiredness, myalgia and vomiting.

CONCLUSION

The results of this study compared favourably with the responses of patients treated with radiation therapy and chemotherapy. The study continues with accrual of additional patients.