Temozolomide and oral VP-16 for children and young adults with recurrent or treatment-induced malignant gliomas

A deep analysis using panel-based next-generation sequencing in an Ecuadorian pediatric patient with anaplastic astrocytoma: a case report

BACKGROUND

Anaplastic astrocytoma is a rare disorder in children from 10 to 14 years of age, with an estimated 0.38 new cases per 100,000 people per year worldwide. Panel-based next-generation sequencing opens new possibilities for diagnosis and therapy of rare diseases such as this one. Because it has never been genetically studied in the Ecuadorian population, we chose to genetically characterize an Ecuadorian pediatric patient with anaplastic astrocytoma for the first time. Doing so allows us to provide new insights into anaplastic astrocytoma diagnosis and treatment.

CASE PRESENTATION

Our patient was a 13-year-old Mestizo girl with an extensive family history of cancer who was diagnosed with anaplastic astrocytoma. According to ClinVar, SIFT, and PolyPhen, the patient harbored 354 genomic alterations in 100 genes. These variants were mostly implicated in deoxyribonucleic acid (DNA) repair. The top five most altered genes were FANCD2, NF1, FANCA, FANCI, and WRN. Even though TP53 presented only five mutations, the rs11540652 single-nucleotide polymorphism classified as pathogenic was found in the patient and her relatives; interestingly, several reports have related it to Li-Fraumeni syndrome. Furthermore, in silico analysis using the Open Targets Platform revealed two clinical trials for pediatric anaplastic astrocytoma (studying cabozantinib, ribociclib, and everolimus) and 118 drugs that target the patient's variants, but the studies were not designed specifically to treat pediatric anaplastic astrocytoma.

CONCLUSIONS

Next-generation sequencing allows genomic characterization of rare diseases; for instance, this study unraveled a pathogenic single-nucleotide polymorphism related to Li-Fraumeni syndrome and identified possible new drugs that specifically target the patient's variants. Molecular tools should be implemented in routine clinical practice for early detection and effective preemptive intervention delivery and treatment.

Temozolomide and oral etoposide in children with recurrent malignant brain tumors

Despite advances in the treatment of brain tumors, the prognosis of children with recurrent malignant brain tumors remains poor. Etoposide (VP-16), an inhibitor of nuclear enzyme deoxyribonucleic acid (DNA)-topoisomerase II, has shown activity in brain tumors. Its efficacy appears schedule dependent but, to date, the most effective schedule of administration has not been well defined. Temozolomide (TMZ), like VP-16, penetrates the blood–brain barrier and has activity against malignant brain tumors. This novel alkylating agent is rapidly absorbed and is highly bioavailable after oral administration. The antitumor activity of TMZ has been shown to be schedule dependent. Based on the evidence of different mechanisms of cytotoxicity, TMZ and VP-16 have been utilized in combination in patients with malignant brain tumors. This review evaluates the results derived from the combination use of TMZ and oral VP-16. The reported data suggest potential activity of oral VP-16 and TMZ alone or in combination. Further clinical trials are needed to explore and confirm their promising activity in relapsed brain neoplasms.

Successful treatment of metastatic cerebral recurrence of pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare pediatric tumor. The central nervous system (CNS) is the most common site of extrathoracic metastasis. The prognosis of PPB patients with CNS metastases is dismal: most patients die within one year after recurrence. Here, we describe two patients diagnosed with PPB who developed intracranial recurrences shortly after the end of their initial treatment and were successfully treated by gross total resection, radiotherapy, and chemotherapy. Both patients are in complete remission four and three years after recurrence. Although an optimal regimen remains to be determined, these cases demonstrate that PPB with CNS metastases is potentially curable.

Old drugs still work! Oral etoposide in a relapsed medulloblastoma

Medulloblastoma is the most common malignant brain tumor in children. Approximately 30% of children with medulloblastoma will progress or relapse despite being treated. New therapies have been proposed in recent years, including high-dose chemotherapy, immunotherapy, and targeted therapy. However, the best treatment for these patients remains unclear, and in this situation prognosis is poor. Oral etoposide has been used as a single agent or in combination for treating relapsed brain tumors since the 1990s. We report an 8-year-old patient with recurrent metastatic medulloblastoma who had an excellent response after treatment with oral etoposide, maintaining a great quality of life. As clinicians, we must always try to include our patients in clinical trials; however, when this is not possible, we should not forget that "old drugs" such as oral etoposide may work in some patients, with a good response of the tumor, and what is most important, providing the patient with a good quality of life.

Two Cases of Pediatric High-Grade Astroblastoma with Different Clinical Behavior

Astroblastoma is a rare glial tumor occurring in older children and defined by histological criteria as low or high-grade. We describe two children with high-grade astroblastoma. The first patient, with multiple recurrences of a frontoparietal tumor, died 10 years from diagnosis after progression of the disease despite surgery, radiotherapy and chemotherapy. The second patient underwent subtotal resection of a temporal mass; the residual tumor progressed five months after radiotherapy, but after a subsequent gross total resection the patient is now in complete remission 54 months from diagnosis. Although both patients had high-grade astroblastomas, there were histological differences between the two tumors, in particular regarding the proliferative index, which was 30% and 5–10%, respectively.

High-grade astroblastoma is usually treated with surgery and radiotherapy, but may have an unpredictable behavior even when tumor excision is deemed complete. The two cases reported here illustrate the variable clinical course of this rare tumor. The proliferative index may be a useful tool to better define prognosis.

Treating recurrent glioblastoma: an update

Glioblastoma, the most aggressive of the gliomas, has a high recurrence and mortality rate. The nature of this poor prognosis resides in the molecular heterogeneity and phenotypic features of this tumor. Despite research advances in understanding the molecular biology, it has been difficult to translate this knowledge into effective treatment. Nearly all will have tumor recurrence, yet to date very few therapies have established efficacy as salvage regimens. This challenge is further complicated by imaging confounders and to an even greater degree by the ever increasing molecular heterogeneity that is thought to be both sporadic and treatment-induced. The development of novel clinical trial designs to support the development and testing of novel treatment regimens and drug delivery strategies underscore the need for more precise techniques in imaging and better surrogate markers to help determine treatment response. This review summarizes recent approaches to treat patients with recurrent glioblastoma and considers future perspectives.

Phase II study of irinotecan in combination with temozolomide (TEMIRI) in children with recurrent or refractory medulloblastoma: a joint ITCC and SIOPE brain tumor study

BACKGROUND

This multicenter phase II study investigated temozolomide + irinotecan (TEMIRI) treatment in children with relapsed or refractory medulloblastoma.

METHODS

Patients received temozolomide 100-125 mg/m(2)/day (days 1-5) and irinotecan 10 mg/m(2)/day (days 1-5 and 8-12) every 3 weeks. The primary endpoint was tumor response within the first 4 cycles confirmed ≥4 weeks and assessed by an external response review committee (ERRC). In a 2-stage Optimum Simon design, ≥6 responses in the first 15 evaluable patients were required within the first 4 cycles for continued enrollment; a total of 19 responses from the first 46 evaluable patients was considered successful.

RESULTS

Sixty-six patients were treated. Seven responses were recorded during stage 1 and 15 in the first 46 ERRC evaluated patients (2 complete responses and 13 partial responses). The objective response rate during the first 4 cycles was 32.6% (95% confidence interval [CI], 19.5%-48.0%). Median duration of response was 27.0 weeks (7.7-44.1 wk). In 63 patients evaluated by local investigators, the objective response rate was 33.3% (95% CI, 22.0%-46.3%), and 68.3% (95% CI, 55.3%-79.4%) experienced clinical benefit. Median survival was 16.7 months (95% CI, 13.3-19.8). The most common grade 3 treatment-related nonhematologic adverse event was diarrhea (7.6%). Grade 3/4 treatment-related hematologic adverse events included neutropenia (16.7%), thrombocytopenia (12.1%), anemia (9.1%), and lymphopenia (9%).

CONCLUSIONS

The planned study primary endpoint was not met. However, its tolerability makes TEMIRI a suitable candidate chemotherapy backbone for molecularly targeted agents in future trials in this setting.

Phase I study of temozolomide combined with oral etoposide in children with malignant glial tumors

The treatment of children with malignant glioma remains challenging. The aim of this multicenter phase I study is to establish the recommended dose (RD) of the combination therapy with temozolomide (TMZ) and oral etoposide (VP-16) in children with relapsed or refractory malignant glioma and brainstem glioma at diagnosis. A phase I trial was conducted to establish the maximum tolerated dose (MTD) of TMZ and oral VP-16. This orally administered combination was investigated by a classical 3 + 3 design. Cohorts of patients were enrolled at 4 different levels: (1) TMZ 120 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-8; (2) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-8; (3) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-10; (4) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-12. Therapy was administered in 28-day courses. A total of 118 courses were administered to 18 patients with a median age of 11.2 years. At dose level 1, none displayed toxicity. Of the 6 patients at dose level 2, 1 patient had dose limiting toxicity (DLT). None of the 3 patients at dose level 3 had DLT. At dose level 4, grade III/IV thrombocytopenia and neutropenia were observed in 2 out of the 6 patients enrolled. Therefore, the MTD was established at dose level 3. The RD for phase II trial in children with malignant glial is TMZ 150 mg/m(2) for 5 days and VP-16 50 mg/m(2) for 10 days every 28 days.

Temozolomide in relapsed pediatric brain tumors: 14 cases from a single center

AIM

Temozolomide is an active drug against gliomas in adults. It also has some promising effects in pediatric patients with brain tumors. We have conducted a retrospective study to investigate the effectiveness of temozolomide in patients with relapsed brain tumors.

PATIENTS AND METHODS

The files of 14 children treated at our hospital between 2005 and 2010 with the diagnoses of relapsed brain tumors were reviewed for pathological characteristics, treatment results, and outcomes.

RESULTS

The median age at relapse was 8 years (range, 1.08-23; F/M, 5/9). Diagnoses included medulloblastoma (n = 5), atypical teratoid rhabdoid tumor (n = 2), ependymoma (n = 2), glioneuronal tumor (n = 1), malignant neoplasm (n = 1), pontine glioma (n = 1), astrocytoma grade III (n = 1), and glioblastoma multiforme (n = 1). All patients except the one with pontine glioma had undergone surgical resection, and all had prior adjuvant chemotherapy. Twelve out of 14 patients had received radiotherapy. The median number of temozolomide courses was 5.0 (range, 1-24). Objective response rate in our patients was 35.7% (three complete responses, one partial response, and one minor response). Stable disease achieved in 14.3% of patients and 50% had progressive disease. Median survival time was 8 months (range, 1-55). At the end of the study, three patients were alive. Hematological toxicity was seen in 30.8% of all courses.

CONCLUSIONS

Relapsed brain tumors in childhood have an unfavorable prognosis. These data suggest that temozolomide might be an active agent against recurrent medulloblastoma. Although overall objective response rate was low, further multicentric studies with temozolomide may be warranted in children with recurrent brain tumors.

Phase I study of temozolomide combined with oral etoposide in children with recurrent or progressive medulloblastoma

BACKGROUND

The prognosis of recurrent or progressive medulloblastoma (MB) is still poor. This study was designed to investigate the potential therapeutic benefit of combination therapy with temozolomide (TMZ) and oral etoposide (VP-16) in children with progressive or relapsed MB. Given the oral administration of both drugs the regimen was administered outpatient.

METHODS

A phase I trial was conducted to establish the maximum tolerated dose (MTD) of TMZ and oral VP-16. This orally administered combination was investigated by classical 3+3 design. Cohorts of patients were enrolled at four different levels: (1) TMZ 120 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-8; (2) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-8; (3) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-10; (4) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-12. Therapy was administered in 28-d courses. A total of 66 courses were administered to 14 patients with a median age of 5.7 years.

RESULTS

None of the 3 patients at dose levels 1 and 2 had dose-limiting toxicity (DLT). Of the 6 patients at dose level 3, 1 patient had DLT. At dose level 4, grade 4 thrombocytopaenia and neutropaenia were observed in the first 2 patients enrolled. Therefore, the MTD was established at dose level 3.

CONCLUSION

The recommended phase II dose in children is TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-10 every 28 d. The combination was well tolerated and demonstrated antitumour activity.

Adjuvant dendritic cell-based tumour vaccination for children with malignant brain tumours

BACKGROUND

A large experience with dendritic cell (DC)-based vaccination for malignant brain tumours has been gained in adults. Here we focus on the results obtained in children with relapsed malignant brain tumours.

PROCEDURE

In total 45 children were vaccinated: 33 high grade glioma (HGG), 5 medulloblastoma (MB)/primitive neuro-ectodermal tumour (PNET), 4 ependymoma and 3 atypical teratoid-rhabdoid tumour (ATRT). Autologous, monocyte-derived DC were generated and loaded with tumour lysate, which was used as source of tumour-associated antigens.

RESULTS

In 38 patients peripheral blood mononuclear cells (PBMC) were obtained from leukapheresis and in 7 patients from fresh blood samples. 7 HGG patients are still alive with median follow-up (FU) of 35.7 months (range: 12.1-85.6). Median overall survival (OS) was 13.5 months (range: 1.4-85.6). All patients with MB/PNET died (median OS 5.7 months; range 4.3-51.2). One patient with ependymoma is still alive at 22.3 months FU. The other three patients died at, respectively, 7.7, 30.1 and 31.5 months. Two patients with ATRT are still alive at, respectively, 34.1 and 52.6 months FU. The third patient died at 50.5 months. No severe adverse events were noticed.

CONCLUSIONS

In this exploratory study, HGG and ATRT seem to respond more favourably to vaccination than MB/PNET and ependymoma. Although preliminary, our results are promising and support further testing of DC-based immunotherapy in new treatment protocols for HGG and ATRT.

Localized BCNU chemotherapy and the multimodal management of malignant glioma

BACKGROUND

Gliomas account for 42% of all primary CNS neoplasms and 77% of all malignant primary CNS neoplasms. Unfortunately the high-grade variant of gliomas, glioblastoma multiforme (GBM), is difficult to treat and generally considered incurable. Survival rates are generally poor, and neurological morbidity in the setting of disease progression is high. Fortunately, significant progress has been achieved in the past decade in our understanding of the molecular biology of this aggressive tumour histology and, as a consequence, there is renewed clinical trial activity in this area focused on improving quality of life, treatment-related morbidity and outcomes.

METHODS

A review of literature from June 2005 to June 2008 was conducted on multimodal treatment of malignant glioma (MG) patients, using specific search criteria in Medline, EMBASE, and BIOSIS. Abstracts from relevant US and European medical (cancer) meetings were also evaluated.

RESULTS

The established therapies for MG include surgery, radiotherapy (RT), and local or systemic chemotherapy. However, over the last 10 years only two chemotherapeutic agents have received regulatory approval for treatment of MG: polifeprosan 20 with carmustine (BCNU implant) and temozolomide (TMZ), an imidazotetrazine derivative of dacarbazine. More recent advances in the treatment of brain tumours have been in the development of multimodal approaches. Specific interest in the combination of BCNU implant and TMZ has arisen due to the demonstrable depletion by TMZ of the DNA repair enzyme responsible for resistance to a nitrosourea such as BCNU. Further interest in this combination stems from the observation that there is a difference in the time to peak effect for each agent. Additional emerging data suggest that multimodal therapy with maximal resection and BCNU implants, followed by adjuvant therapy with radiation and TMZ, is effective and well-tolerated in patients with initial high-grade, resectable MG.

CONCLUSIONS

The increasing body of efficacy data suggests that this combination of BCNU implants and TMZ within a multimodal treatment strategy including surgery and RT may provide an enhanced benefit compared with the use of either of these agents alone in select patients with high-grade glioma.

Increased survivin expression confers chemoresistance to tumor-associated endothelial cells

Growing evidence suggests that survivin, a member of the inhibitor of apoptosis gene family, is responsible for drug resistance in cancer cells, yet little is known about its role in the endothelial cells of the tumor vasculature. We have previously reported that tumor-associated endothelial cells derived from gliomas (TuBECs) are resistant to anticancer chemotherapy whereas normal brain endothelial cells (BECs) are sensitive. The focus of this study is to investigate the mechanism behind this chemoresistance. Here we show that survivin is constitutively overexpressed in the glioma vasculature but not in the blood vessels of normal brain. To determine whether survivin contributes to TuBEC chemoresistance, we used a lentiviral siRNA system or the drug roscovitine to down-regulate survivin expression. Reduced levels of survivin sensitized TuBECs to the chemotherapeutic agents VP-16, paclitaxel, thapsigargin, and temozolomide. This cell death was mediated through caspases 7 and 4. Conversely, forced expression of survivin in BECs was protective against drug cytotoxicity. These data suggest that overexpression of survivin in endothelial cells serves as a protective mechanism that defends the vasculature from drug cytotoxicity. Our studies demonstrate that targeting survivin may be an effective approach to chemosensitization and anti-vascular therapy for brain tumors.

The combined effects of multiple chemotherapeutic agents for malignant glioma cells

The prognosis of malignant gliomas remains poor, despite the progress of surgery and radiotherapy. Chemotherapy has been shown to prolong an overall survival, but the benefits are still small. To overcome this situation, the optimal regimen of antineoplastic agents is required. In the present study, we investigated the effect of the association of five chemotherapeutic drugs, including ACNU, CBDCA, CDDP, VCR, and VP-16, on cell survival of U87, YKG1, A172, and U251 human glioma cell lines, using median-effect analysis. A synergistic effect was obtained by treatment involving the association of VP-16 with ACNU or CDDP among the combinations of two drugs, and the association of ACNU, CBDCA, and VP-16 in the combination of three drugs. This preclinical screening using median-effect analysis supports the design of clinical trials by indicating more effective combinations of antineoplastic agents for malignant gliomas.

Outcome of secondary high-grade glioma in children previously treated for a malignant condition: A study of the Canadian Pediatric Brain Tumour Consortium

BACKGROUND AND PURPOSE

Reports of secondary high-grade glioma (HGG) in survivors of childhood cancer are scarce. The aim of this study was to review the pattern of diagnosis, the treatment, and outcome of secondary pediatric HGG.

PATIENTS AND METHODS

We performed a multi-center retrospective study among the 17 paediatric institutions participating in the Canadian Pediatric Brain Tumour Consortium (CPBTC).

RESULTS

We report on 18 patients (14 males, 4 females) treated in childhood for a primary cancer, who subsequently developed a HGG as a second malignancy. All patients had previously received radiation therapy +/- chemotherapy for either acute lymphoblastic leukaemia (n=9) or solid tumour (n=9). All HGG occurred within the previous radiation fields. At the last follow-up, 17 patients have died and the median survival time is 9.75 months.

CONCLUSION

Although aggressive treatment seems to provide sustained remissions in some patients, the optimal management is still to be defined. Further documentation of such cases is necessary in order to better understand the pathogenesis, the natural history and the prevention of these tumours.