Chemotherapy of low-grade gliomas

Changes in neurocognitive functioning and quality of life in adult patients with brain tumors treated with radiotherapy

This review aims to summarize what is currently known about neurocognitive outcome and quality of life in patients with brain tumors treated with radiotherapy. Whether potential tumor-controlling benefits of radiotherapy outweigh its potential toxicity in the natural history of brain tumors is a matter of debate. This review focuses on some of the adult main brain tumors, for which the issue of neurocognitive decline has been thoroughly studied: low-grade gliomas, brain metastases, and primary central nervous system lymphomas. The aims of this review are: (1) the analysis of existing data regarding the relationship between radiotherapy and neurocognitive outcome; (2) the identification of strategies to minimize radiotherapy-related neurotoxicity by reducing the dose or the volume; (3) the evidence-based data concerning radiotherapy withdrawal; and (4) the definition of patients subgroups that could benefit from immediate radiotherapy. For high grade gliomas, the main findings from literature are summarized and some strategies to reduce the neurotoxicity of the treatment are presented. Although further prospective studies with adequate neuropsychological follow-up are needed, this article suggests that cognitive deficits in patients with brain tumor have a multifactorial genesis: radiotherapy may contribute to the neurocognitive deterioration, but the causes of this decline include the tumor itself, disease progression, other treatment modalities and comorbidities. Treatment variables, such as total and fractional dose, target volume, and irradiation technique can dramatically affect the safety of radiotherapy: optimizing radiation parameters could be an excellent approach to improve outcome and to reduce neurotoxicity. At the same time, delayed radiotherapy could be a valid option for highly selected patients.

Feasibility and efficacy of repeated chemotherapy for progressive pediatric low-grade gliomas

BACKGROUND

Chemotherapy is widely accepted as first-line therapy for pediatric low-grade gliomas (LGG). Treatment modalities for further progression are not clearly established. The aim of the study was to determine the feasibility and long-term outcome of repeated chemotherapy for children with recurrent LGG.

METHODS

The study group consisted of patients who received a second line of chemotherapy at progression of their LGG. We compared toxicity, progression-free survival (PFS), and overall survival (OS) of patients treated with chemotherapy at the time of initial diagnosis and patients who received another treatment with chemotherapy at further progression.

RESULTS

Between 1985 and 2009, 118 patients received chemotherapy as primary treatment for LGG, 38 had repeated chemotherapy at further progression. Chemotherapy was tolerated extremely well. Ninety-two percent of patients completed their second line protocol and toxicity was comparable between initial and second line chemotherapy. Five-year OS and PFS were 86 ± 6% and 37 ± 8%, respectively, which were similar to first-line chemotherapy (P = 0.14). Repeated chemotherapy courses were not associated with worsening of visual, neuroendocrine, or other long-term organ sequelae.

CONCLUSION

This study demonstrates high feasibility and low mortality of repeated chemotherapy treatment for progressive LGG. The chronic nature of LGG concerning tumor progression justifies consideration of non-toxic second-line treatment regimens at the time of recurrence. Prospective studies focusing on toxicity and long-term outcome are needed to substantiate this approach.

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.

Anaplastic oligodendroglioma responding favorably to intranasal delivery of perillyl alcohol: a case report and literature review

BACKGROUND

In recent years, molecular genetics and biology are exerting significant influence on the practice of neuro-oncology, with oligodendrogliomas being the most prominent example. To explore therapeutic strategies and evaluate the clinical results, we report a case of a patient with anaplastic oligodendroglioma managed with intranasal delivery of POH.

CASE DESCRIPTION

A 62 year-old white woman presented with complaints of seizures and frontal headache in June 1999. Nervous system examination was normal. Her Karnofsky performance score was 90. A contrast-enhanced MRI scan of the brain revealed a regular space-occupying lesion in the right frontal lobe that enhanced with gadolinium. A radical surgical excision of the tumor was carried out, and the histopathological diagnosis was an anaplastic oligodendroglioma. Subsequently, there were 2 recurrent/progressive lesions, in July 2002 and October 2004, despite combination treatment using surgery, radiotherapy, and chemotherapy. Intranasal delivery of 0.3% concentration of POH 4 times daily was performed. A follow-up MRI scan after 5 months of treatment revealed reduction in size of the enhancing lesion.

CONCLUSION

Whereas surgery continues to be the primary treatment for oligodendroglioma, the scheme for postoperative therapy has shifted primarily because of the lesion's relative chemosensitivity. This article evaluates the effects of intranasal delivery of POH in a case of regression of anaplastic oligodendroglioma.

The treatment of malignant gliomas

The optimal management of patients with malignant gliomas begins with the accurate determination of the pathologic diagnosis based on adequate sampling of the tumor. Clear differences in prognosis and therapeutic options have been established for the various tumor grades and cellular classification. Current recommendations, on the basis of the results of a recent phase III randomized trial, are that patients with glioblastoma should have maximal surgical resection followed by concurrent radiation and chemotherapy with temozolomide. It is further recommended that patients then be treated with 6 to 12 months of adjuvant temozolomide. However, despite the shown improvement in survival with this chemoradiation regimen, the impact on outcome is modest. It is increasingly evident that a greater understanding of the molecular mechanisms of gliomagenesis is needed to improve treatments for these patients. Recent and ongoing investigations strongly indicate that specific molecular markers tremendously impact prognosis and often can predict response to treatment. For example, allelic loss of the 1p and 19q chromosome arms predicts a dramatic improvement in response to treatment and survival for tumors histologically classified as anaplastic oligodendroglioma. Future advances for treating primary brain tumors likely will be directly related to our ability to molecularly subcategorize tumors and customize therapy based on the molecular profile within each histologic type and grade of tumor. This is evident in preliminary data indicating that inactivation of the methyl guanine methyltransferase gene by hypermethylation of the promoter region specifically predicts a better tumor response rate to chemotherapies that alkylate DNA as their mechanism of action. Similarly, elucidation of overly active signal transduction pathways within tumor cells may provide an opportunity to select the optimal therapeutic regimen composed of modulators of these pathways, analogous to restricting the use of trastuzumab to breast cancers expressing the Her-2 receptor. Advances in treating primary malignant brain tumors will likely depend on collaborative clinical trials that are designed to select patients on the basis of histologic and molecular characteristics and to determine the optimal biologic dose of the best agent that can treat each specific tumor type.

[Supratentorial low grade glioma in adults: an experience with 23 surgical cases]

Low-grade supratentorial astrocytomas and oligodendrogliomas in adults are uncommon tumors of the central nervous system. We analyzed retrospectively 23 patients with this type of neoplasia, who were operated on between 1986 and 2002. There were no post-operative deaths. The survival rate at 5 and 10 years post-surgery for the entire sample was 67 and 30% respectively, similar to other outcomes. With 14 patients we achieved a complete removal of the lesion (60.8%) and with 9 (39.2%) partial removal of the tumor. In the sub-group which underwent total resection of the tumor, 89% survived 5 years and 45% attained 10 years of survival, in contrast with the sub-group that underwent partial removal in which only 35% attained 5 years of survival and none 10 years. Due to the deleterious effects of radiation therapy, we preferred to prescribe it only in cases of tumor recurrence.

Low-grade glioma: supratentorial astrocytoma, oligodendroglioma, and oligoastrocytoma in adults

Low-grade glioma is not a single diagnosis but a category of biologically diverse neoplasms. They are indolent, progressive, and, following anaplastic transformation, invariably fatal. Neuro-oncologists have not established a treatment standard for these tumors. However, it is clear that "low-grade" is not synonymous with "benign," and treatment is required sometime in the course of the disease. Previously, achieving a consensus had been limited by a lack of class I evidence. Physicians treated patients based on retrospective series and personal experience. Currently, results from prospective clinical trials are becoming available. These studies have provided data that may serve as treatment guidelines. Additional results regarding the identification of prognostic variables have raised more questions to be answered. Attention is now directed to the importance of translational research to better define these neoplasms. In the future, it will be necessary to distinguish among low-grade gliomas and identify therapies that may differ between them.

Surgical outcome following resection of contrast-enhanced pediatric brainstem gliomas

BACKGROUND

The role of surgery in the management of gadolinium-enhancing pediatric brainstem lesions on magnetic resonance imaging (MRI) has been a matter of open debate. This clinical series correlates radiological and pathological findings to assess the role of contrast enhancement as an indication for surgery with respect to clinical outcome.

METHODS

We retrospectively reviewed the charts of all pediatric patients admitted to the Johns Hopkins Hospital with a diagnosis of a brainstem tumor between January 1985 and December 2000.

RESULTS

There were a total of 89 patients who met the inclusion criteria. Fifty-seven patients (64.0%) underwent surgical resection while 32 (36%) were treated with radiation and/or chemotherapy. Of the surgical candidates, 57 (100%) had an accompanying MRI scan significant for an enhancing lesion in the midbrain, pons or the medulla. The pathology was consistent with juvenile pilocytic astrocytoma in 30 patients (52.6%) and glioblastoma multiforme in 12 patients (21.1%). The remaining cases consisted of 10 patients (17.5%) with fibrillary astrocytomas, 3 (5.3%) with gangliogliomas, 1 (1.8%) with an oligodendroglioma and 1 (1.8%) with a primitive neuroectodermal tumor. A total of 29 patients had a total surgical resection, 8 a near total resection (>90%), 15 a subtotal resection (50-90%) and 5 a partial resection (<50%). The progression-free survival of all patients was 71.9% at 3 years and 45.6% at 5 years.

CONCLUSIONS

This case series illustrates that contrast-enhanced MRI has positive prognostic value in the management of pediatric brainstem gliomas. In our study, the majority of enhancing tumors were low grade and amenable to surgical intervention. Consequently, we recommend surgical resection and pathological diagnosis of all enhancing brainstem tumors with adjuvant therapy reserved for recurrent or unresectable cases.

Treatment of low-grade diffuse astrocytomas by surgery and human fibroblast interferon without radiation therapy

Low-grade diffuse astrocytomas are slowly growing tumors with a relatively long overall survival. However, a substantial proportion undergoes dedifferentiation to a more malignant phenotype. Considerable controversy exists as to the best therapeutic management for patients with such tumors. Over the past decade, we have applied human fibroblast interferon (HFIF) therapy without radiation therapy to low-grade astrocytomas. We investigated 28 patients with WHO grade II astrocytomas of the cerebral hemispheres treated by surgery plus HFIF therapy. The overall response rate to the HFIF therapy was 36%. All side-effects of HFIF were transient, tolerable and manageable. The 5-year progression free survival and overall survival probabilities were 65% and 96%, respectively. Although our data from small cohort of patients may have modest value, our results suggest that HFIF may be useful in treating low-grade diffuse astrocytomas.

Posterior fossa oligodendroglioma

Oligodendroglioma are the tumors of glial cells. They are rare in children and are more common in the cerebral hemispheres. A rare case of infratentorial oligodendroglioma in a female child is being reported here.

Current diagnosis and treatment of oligodendroglioma

Object

The strategies used to diagnose and treat oligodendroglial tumors have changed significantly over the past decade. The purpose of this paper is to review the topic of oligodendroglioma, emphasizing the new developments.

Methods

Information was obtained by conducting a Medline search in which the term oligodendroglioma was used. Recent editions of standard textbooks were also studied.

Because of tools such as magnetic resonance imaging, oligodendrogliomas are being diagnosed earlier, and they are being recognized more frequently histologically than in the past. Seizures are common in these patients. Functional mapping and image-guided surgery may now allow for a safer and more complete resection, especially when tumors are located in difficult areas. Genetic analysis and positron emission tomography may provide data that supplement the standard diagnostic tools. Unlike other low-grade gliomas, patients in whom residual or recurrent oligodendroglioma (World Health Organization Grade II) is present may respond to chemotherapy. Although postoperative radiotherapy prolongs survival of the patient, increasingly this therapeutic modality is being delayed until tumor recurrence, especially if a gross-total tumor resection has been achieved. Oligodendrogliomas are the first type of brain tumor for which “molecular” characterization gives important information. The most significant finding is that allelic losses on chromosomes 1p and 19q indicate a favorable response to chemotherapy.

Conclusions

Whereas surgery continues to be the primary treatment for oligodendroglioma, the scheme for postoperative therapy has shifted, primarily because of the lesion's relative chemosensitivity. Molecular characterization of oligodendrogliomas may become a standard practice in the near future.

Randomized trials of radiation therapy in adult low-grade gliomas

There are two central questions in the radiotherapeutic management of the adult patient with a supratentorial low-grade (WHO grade II) astrocytoma, oligo-astrocytoma, or oligodendroglioma. The first question is one of timing. Following tissue diagnosis with or without maximum surgical resection, should immediate postoperative radiation therapy (RT) be given, or should RT be deferred to the time of local recurrence? The second question is one of dose. Assuming RT is given, should lower doses (ie, approximately 45-50 Gray (Gy)) or higher doses (ie, approximately 60-65 Gy) be administered? One Phase III prospective randomized clinical trial addressing the first question and two addressing the second question have been performed. Their results suggest that delayed (versus immediate) RT and low-dose (versus high-dose) RT are both acceptable treatment strategies despite the bias amongst radiation oncologists (primarily based on retrospective data) that immediate and high-dose RT would result in better outcome. The schema of the ongoing Radiation Therapy Oncology Group study is presented.