Chemotherapy of malignant gliomas

Adjuvant chemotherapy for adults with malignant glioma: a systematic review

OBJECTIVE

This systematic review examines the role of chemotherapy following surgery and external beam radiotherapy for adults with newly diagnosed malignant glioma.

METHODS

MEDLINE, EMBASE, and the Cochrane Library databases were searched to August 2006 to identify relevant randomized controlled trials (RCTs) and meta-analyses. Proceedings from the 1997 to 2006 annual meetings of the American Society of Clinical Oncology were also searched.

RESULTS

Two RCTs reported a survival advantage in favour of radiotherapy with concomitant and adjuvant temozolomide compared with radiotherapy alone in patients with anaplastic astrocytoma or glioblastoma. Twenty-six RCTs and two meta-analyses detected either no advantage or a small survival advantage in favour of adjuvant chemotherapy.

CONCLUSION

Concomitant temozolomide during radiotherapy and post-radiation adjuvant temozolomide is recommended for all patients ages 18-70 with newly diagnosed glioblastoma multiforme who are fit for radical therapy (ECOG 0-1). Temozolomide may be considered in other situations (i.e., ECOG 2, biopsy only, age > 70, intermediate grade glioma), but there is no high-level evidence to support this decision. Moreover, there are few data on long-term toxicities or quality of life with temozolomide. Adjuvant chemotherapy may be an option for younger patients with anaplastic (grade 3) astrocytoma and patients with pure or mixed oligodendroglioma. However, there is no evidence of a survival advantage from adjuvant chemotherapy in these patients, and treatment-related adverse effects and their impact upon quality of life are poorly studied. The combination of procarbazine, lomustine, and vincristine (PCV) is not recommended for patients with anaplastic oligodendroglioma and oligoastrocytoma.

Effect of surgical removal on survival and quality of life in patients with supratentorial glioblastoma

The relationship between the extent of tumor resection and the progression-free survival, overall survival, and quality of life was evaluated retrospectively in 105 consecutive adult patients with supratentorial hemispheric glioblastoma not primarily involving the basal ganglia, thalamus, or hypothalamus. All patients underwent multidisciplinary treatment including tumor removal and postoperative adjuvant therapy in prospective randomized trials designed to test several chemotherapy regimens. Magnetic resonance imaging with contrast medium was used to determine the extent of tumor resection. Gross total resection (GTR) was performed in 35 patients (33%), partial resection (PR) in 57 (54%), and biopsy in 13 (12%). Univariate and multivariate analysis was performed to assess the prognostic relevance of the extent of resection. The Karnofsky performance status (KPS) improved from 78% to 83% in the GTR group. The difference was not statistically significant. There was no significant change in the PR (from 70% to 72%) and the biopsy groups (from 64% to 62%). Progression- free survival was significantly longer in the GTR group (median survival time [MST] 10.3 months) than in the PR (MST 5.2 months) and the biopsy groups (MST 3.6 months). The overall survival was significantly longer in the GTR group (MST 20 months) than in the PR (MST 14.2 months) and the biopsy groups (MST 8.3 months). The difference in survival between the PR and the biopsy groups was not statistically significant. GTR prolongs the survival of patients with glioblastoma compared to PR or biopsy.

Extreme drug resistance in primary brain tumors: in vitro analysis of 64 resection specimens

Understanding chemoresistance profiles of brain tumors may aid in more educated selection of chemotherapeutic regimens for clinical trials and patient treatment. Although the literature contains many reports of the application of drug resistance assays, little is known about extreme drug resistance (EDR) in primary brain tumors. We undertook this study to determine chemoresistance profiles for brain tumors. From September 1991 to February 1998, we collected 64 brain tumor specimens from patients admitted to the Johns Hopkins Hospital. Tumors were classified according to the revised World Health Organization system. Brain tumor specimens were tested against 13 different chemotherapeutic agents using an extreme drug resistance assay. Results were reported as percent cell inhibition (PCI) (compared to control cultures). A drug resistance profile (extreme, intermediate, or low) was determined based on statistical comparison to a historical database of tumor specimens tested against the same panel of chemotherapeutic agents. Brain tumor specimens were classified histologically as Grade IV astrocytoma (glioblastoma multiforme, n = 35), Grade II/III astrocytoma (n = 11), oligodendroglioma (n = 6), meningioma (n = 9), hemangiopericytoma (n = 2), and ependymoma (n = 1). A large percentage of glioblastomas displayed extreme drug resistance to paclitaxel (69%, n = 35), SN38 (75%, n = 28), and vincristine (38%, n = 29). The majority of Grade II/III astrocytomas displayed extreme drug resistance to carboplatin (67%, n = 6), cisplatin (60%, n = 10), and paclitaxel (60%, n = 10). In a similar fashion, oligodendrogliomas displayed extreme drug resistance to vincristine (60%, n = 5) and paclitaxel (50% n = 6). Most meningiomas displayed extreme drug resistance to vincristine (75%, n = 8), dacarbazine (63%, n = 8), and 4-HC (50%, n = 8). Through the continued analysis of brain tumor specimens and compilation of data from multiple institutions, chemoresistance profiles could assist in the development of rationale clinical trials and treatment regimens for patients with brain tumors.

ACNU, MTX and 5-FU penetration of rat brain tissue and tumors

The distribution of radio-labeled ACNU, MTX and 5-FU in brain and tumor tissue was studied in female Wistar rats by macroautoradiography after intrathecal administration. In normal rats, ACNU and 5-FU, administered intracisternally, distributed rapidly in the subarachnoid space, ventricular system and cerebrospinal fluid (CSF). 5-FU and MTX penetrated the brain deeply; the diffusional transport of ACNU was limited to a depth of 1 or 2 mm from the CSF surface of the brain. MTX and 5-FU clearance into the blood circulation was rather slow while ACNU cleared relatively quickly. The half time of ACNU, 5-FU and MTX radioactivity at the ventricular surface was 10, 21, and 110 min, respectively, at their maximal concentration after intracisternal administration. In rats with leptomeningeal tumor induced by intracisternal inoculation of Walker 256 cells, the distribution patterns of ACNU, 5-FU, and MTX were essentially the same as in normal rats despite 10-20 cell layers of tumor growing in the subarachnoid space. 5-FU and MTX were able to penetrate tumor masses in the subarachnoid space; MTX penetration was slower than that of 5-FU and ACNU failed to penetrate to more than a depth of 1 or 2 mm from the tumor surface.

Oligodendroglioma: an appraisal of recent data pertaining to diagnosis and treatment

OBJECTIVE

This article reviews and summarizes recent data on the diagnosis, prognosis, and treatment of oligodendroglial tumors.

METHODS

Histological criteria for optimized diagnosis and grading of oligodendroglial tumors are described and discussed. The therapeutic approaches are analyzed in light of the results of recent series.

RESULTS

Oligodendroglial tumors may be more common than is generally thought. Perinuclear halo and "chicken-wire" pattern, although considered classic histological features of oligodendrogliomas, are unreliable as sole criteria for diagnosis. Nuclear regularity and roundness and an eccentric rim of eosinophilic cytoplasm lacking obvious cell processes are more constant features. Grading should be accomplished using a composite of radiological and histopathological relevant features. The allelic loss of chromosome arms 1p and 19q might be a marker for both chemosensitivity and longer survival after chemotherapy. Oligodendrogliomas are notably chemosensitive when compared with other gliomas. For aggressive lesions, chemotherapy should be used upfront, after surgery.

CONCLUSION

Oligodendrogliomas are underdiagnosed. One unfortunate implication is that a large number of patients may be receiving suboptimal care. A simplification in grading of oligodendroglioma to two grades would reduce the confusion surrounding the classification and better define prognosis and response to treatment modalities. A better definition of the so-called mixed tumor should also allow a better classification of these lesions in an intermediate prognostic class between astrocytic and oligodendroglial lesions. Loss of 1p and 19q could be used as a cytogenetic marker in assisting grading. New concepts emerging in the recent literature should help optimize the diagnosis of these lesions and reduce interobserver variability.

Dose-intensive, time-compressed procarbazine, CCNU, vincristine (PCV) with peripheral blood stem cell support and concurrent radiation in patients with newly diagnosed high-grade gliomas

The dose intensity of the PCV regimen can be doubled using peripheral blood stem cell (PBSC) support. This study sought to determine the feasibility of giving dose-intensive PCV concurrently with radiation therapy. Twelve patients, age 3.2-22.7 years, median 7.5 years, with newly diagnosed high grade gliomas were enrolled. Diagnoses included diffuse intrinsic brainstem gliomas (BSG) (n = 6), glioblastoma (n = 4), anaplastic astrocytoma (n = 2). PBSCs were harvested prior to chemotherapy with G-CSF priming. Chemotherapy consisted of CCNU 130 mg/m2 and vincristine 1.5 mg/m2 on day 0, and procarbazine 150 mg/m2 on days 1-7. PBSCs were reinfused on day 9 of each course. Four courses of chemotherapy were administered every 28 days or when blood counts recovered. The first course was administered the week prior to RT, the second course began on week 3 of RT and the third and fourth course were given after RT. Hematologic toxicity was mild and the majority of courses were given on schedule. Five of six patients with diffuse BSG showed clinical improvement and three showed a radiographic response; however, only one remains alive 12+ months from diagnosis. All four patients with non-brainstem large-volume tumors showed clinical deterioration and radiographic progression during or shortly after RT. MRI scans showed massive edema and enhancement. Median time to radiographic progression was five months. Median overall survival was 11 months. We conclude that dose-intensive, time-compressed PCV given concurrently with large-volume RT appears to result in unacceptable toxicity in patients with large residual tumors.

Targeting chemotherapy for malignant brain tumor using thermosensitive liposome and localized hyperthermia

Thermosensitive liposomes are microscopic vesicles that can contain drugs and release them effectively in response to hyperthermia. To deliver an antitumor drug specifically to brain tumor, the authors used thermosensitive liposomes containing cis-diamminedichloroplatinum (CDDP) in conjunction with localized brain heating. The authors then investigated the antitumor effect on rat malignant glioma. Rous sarcoma virus-induced malignant glioma cells were transplanted into the brains of Fisher rats. Ten days after tumor inoculation, the rats were assigned to one of six treatment groups: control, free CDDP, hyperthermia, free CDDP + hyperthermia, liposomes containing CDDP (CDDP-liposome), and CDDP-liposome + hyperthermia. Liposomes containing CDDP or free CDDP were injected via the tail vein. Brain tumor heating was administered by means of a radiofrequency antenna designed at our institute. The rats treated with CDDP-liposome + hyperthermia had the longest survival time and the tumor CDDP level of this group was the highest when compared to the other groups. Histopathological examination showed that tumor cells were necrotized but surrounding normal brain tissue remained undamaged. On the basis of these findings we suggest that the combination of thermosensitive liposome and localized hyperthermia may better focus antitumor drugs to the tumor, providing a significantly greater antitumor effect.

Radiation therapy combined with radiosensitizing agents for cerebral glioblastoma in adults

We analyzed our treatment results of 71 operated patients with cerebral glioblastoma treated by conventional external radiation therapy (mean dose 60.2 Gy) combined with radiosensitizing agents. More than 50% reduction of tumor volume was obtained in 20 patients (28.2%). A response rate of at least 40% was obtained in patients treated with combined ACNU-vincristine-nicardipine, ACNU-5FU-hydroxyurea, or cisplatin alone. The combination of ACNU and vincristine with or without nicardipine resulted in significantly longer survival. The median survival in this group was 101.1 weeks and the two-year survival rate was 45.9%; these results were significantly better than those achieved with other ACNU combinations or other combinations without ACNU. In the analysis of survival, factors correlated to longer survival were a patient age of younger than 45 years, wide resection of the tumor, a good postoperative performance status (KS > or = 70%), a radiation dose of 68-72 Gy, small postoperative tumor remnants (< 20 cm3), no visible tumor after radiation therapy, and the administration of adjuvant chemotherapy. Maximum resection of the tumor and localized irradiation with a dose of 70 Gy combined with ACNU and vincristine appears to be the most effective treatment at present.

Pharmacokinetics of intrathecal 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride in rats

The pharmacokinetics of intrathecal 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) were studied in female Wistar rats by macroscopical autoradiography using 14C labeled ACNU. In normal rats, ACNU rapidly distributed in the subarachnoid space and ventricles after intracisternal administration. Diffusional transport into the brain tissue was limited to a depth of 1 or 2 mm from the cerebrospinal fluid (CSF) surface of the brain. Clearance of ACNU from the CSF space and brain was relatively fast and the half time of ACNU concentration at the cortical or ventricular surface was 10 min. In rats with leptomeningeal tumor induced by intracisternal inoculation of Walker 256 carcinosarcoma cells, the distribution pattern of ACNU after intracisternal administration was essentially the same as in normal rats until the tumor had grown in the subarachnoid space to form more than 10 or 20 layers of tumor cells. ACNU was distributed in the tumor as well. When the tumor had grown to form masses in the subarachnoid space, ACNU failed to penetrate to more than a depth of 1 or 2 mm from the tumor surface. Our results suggest that intrathecal ACNU administration may have no, or minor side effects on the brain and that it can eliminate floating or thin layered tumor cells in the subarachnoid space but not bulky tumors.

Meta-analysis of radiation therapy with and without adjuvant chemotherapy for malignant gliomas in adults

BACKGROUND

The value of chemotherapy after standard postoperative external beam radiation in the treatment of malignant gliomas remains controversial. Despite recent recommendations from the Brain Tumor Cooperative Group that chemotherapy should be considered part of the standard treatment of patients with high-grade astrocytomas, several recent trials have questioned the efficacy of this approach.

METHODS

Using results from 16 randomized clinical trials involving more than 3000 patients, the authors compared the survival rates of patients who received radiation alone or radiation with chemotherapy. The combined data were analyzed using the statistical method of meta-analysis as described by DerSimonian and Laird.

RESULTS

The estimated increase in survival for patients treated with combination radiation and chemotherapy was 10.1% at 1 year (95% confidence interval, 6.8, 13.3%) and 8.6% at 2 years (5.2, 12.0%). These absolute increases in survival (treated-control [TC]) in patients treated with chemotherapy represent relative increases (T-C)/C of 23.4% at 1 year (15.8, 30.9%) and 52.4% at 2 years (31.7, 73.2%). This survival advantage is conferred by several different chemotherapeutic agents. When the prognostic variables of age and histology are factored into the analysis, however, the data suggest that the survival benefit from chemotherapy occurs earlier in patients with anaplastic astrocytoma (AA) than in patients with glioblastoma.

CONCLUSIONS

The authors concluded that chemotherapy is advantageous for patients with malignant gliomas and should be considered part of the standard therapeutic regimen. Additional randomized trials using optimal radiation and chemotherapy may still be needed to precisely define which subgroups of patients, based on prognostic variables, will benefit most from chemotherapy after radiation.

Intrathecal chemotherapy with ACNU in a meningeal gliomatosis rat model

Intrathecal administration of ACNU ((1-4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitroso urea hydrochloride) had a remarkable chemotherapeutic effect in a rat model of meningeal gliomatosis. This effect was evaluated in rats with meningeal gliomatosis induced by an intracisternal inoculation of rat C6 glioma cells. The median survival time of the rats treated with a single dose of intrathecal ACNU (1 mg/kg) on Day 1 or Day 3 after tumor inoculation was significantly prolonged by 35.7% to 42.9% or 25.0% to 28.6%, respectively, as compared with that of the control animals. Meningeal gliomatosis rat models treated intrathecally with ACNU (1 mg/kg) 5 days after tumor inoculation or intravenously with ACNU (15 mg/kg) both failed to prolong the survival time of the animals. These findings suggest that intrathecal chemotherapy with a low dose of ACNU is effective in the early stages of meningeal gliomatosis, whereas intravenous chemotherapy with a high dose of ACNU is always ineffective.

The effects of local and systemic interferon beta (Fiblaferon) on supratentorial malignant cerebral glioma--a phase II study

In contrast to the highly promising and, with rates up to 40%, surprisingly high response rates of malignant supratentorial brain gliomas to post-operative adjuvant IFN beta therapy, we were unable to demonstrate any definite anti-proliferative, anti-tumor or immunomodulatory effects of interferon in a phase II study in 13 patients. We used high doses of an IFN beta, Fiblaferon, whose potency was repeatedly confirmed by pharmacokinetic investigations, for local and systemic administration, and the times of administration were those used in the Japanese comparative studies. The side effects observed proved to be related to the amount of IFN beta administered and its duration in our patients as well. In this context, the neurotoxic disturbances require particular attention. These resolved completely after discontinuation of IFN treatment, as do the haematological and liver enzyme disturbances after suspension of medication. We did not observe any improvement in the post-operative quality of life, nor, above all, any improvement in long-term prognosis resulting from a prolonged tumor-free remission period and prolongation of the actual post-operative survival time.

Chemotherapy for malignant gliomas of the brain: a review of ten-years experience

In recent years, there has been a great improvement in the knowledge of the biological aspects of malignant gliomas of the brain. Conversely, there has been an increase of interest in the multimodal treatment of these tumours. In this review, we have analyzed the results of the several reports which have appeared in the literature that deal with the chemotherapeutic treatment of malignant gliomas. Furthermore, some areas of biological investigation that could have an impact on pharmacological therapy are discussed.

The management of patients with an intrinsic supratentorial brain tumour

The management of patients presenting with supratentorial glioma between 1978 and 1986 is reviewed. Complete follow-up in 517 cases was obtained. One hundred and fifty eight patients were not submitted to any form of surgery, 299 patients were biopsied and 60 patients underwent craniotomy and internal decompression. The no surgery group contained a higher proportion of patients with poor prognostic indicators than either the biopsy or craniotomy groups. The craniotomy group consisted of patients with better prognostic indicators than the biopsy group, in particular, younger age and more favourable site, type and grade of tumour. This was reflected in the difference in outcome between the groups. Median survival was 14 months in the craniotomy group, four months in the biopsy group and 2.2 months in the no surgery group. The outcome in patients with histologically proven malignant gliomas was best in those patients who received radiotherapy. The craniotomy group had a median survival of 18.5 months, a two year survival of 48% and a five year survival of 9%. The median survival following radiotherapy of those patients with proven malignant gliomas who had a biopsy was 9.5 months with a two year survival of 16% and a five year survival of 2%. These results compare favourably with studies which have adopted a more aggressive approach, suggesting that outcome is determined as much by patient selection using favourable prognostic indicators as by the treatment itself. The need for prospective trials of the management of unselected consecutive glioma patients randomizing them to conservative and radical treatment groups in order to define the role of both conventional therapy and radical therapy is discussed.

The role of chemotherapy in the treatment of gliomas in adults

Glioblastomas and previously irradiated recurrent gliomas remain incurable. Chemotherapy is able to palliate patients by shrinking tumors, thereby improving neurological status and quality of life. Chemotherapy may also be capable of prolonging survival in some instances. The effectiveness of chemotherapy against gliomas is comparable to the efficacy of chemotherapy against many other solid tumors. When given in an adjuvant setting along with radiation postoperatively, studies suggest that the nitrosoureas, dibromodulcitol, dianhydrogalactitol, procarbazine, teniposide, dacarbazine, and cisplatin may possibly be useful, although results for many of these drugs are inconclusive. Some chemotherapy combinations also appear to be useful in an adjuvant setting, particularly BCNU plus ifosfamide, BCNU plus cisplatin, CCNU plus dibromodulcitol, and CCNU plus lonidamine. However, there is not yet conclusive evidence that combination chemotherapy is superior to single agent adjuvant chemotherapy in the treatment of gliomas. While the use of chemotherapy prior to postoperative cranial radiation is worthy of further study, it has not to date proven to be more effective than chemotherapy combined with radiation. In patients whose tumors have recurred following radiation, palliation may be achieved with the nitrosoureas, procarbazine, teniposide, and diaziquone. Cisplatin, high dose methotrexate, the interferons, and a variety of other medications also may be of use. As in the case of adjuvant chemotherapy, chemotherapy combinations for recurrent tumor have not been conclusively demonstrated to be superior to single agent treatment, although some CCNU-based combinations are of interest. Many different chemotherapy drugs have been administered by intracarotid infusion. There is a moderately high risk of serious local retinal and neurological toxicity using this approach, and efficacy has not been proven to be improved by this approach. However, further studies of intraarterial administration of chemotherapy are warranted in light of theoretical considerations, pharmacological observations of enhanced local drug concentrations, and the observation that patients who have failed the same drugs intravenously may respond when lower doses of the drug are administered intraarterially. In addition, some patients have had tumor shrinkage in the area infused while tumor has grown in other areas. Thus, while intracarotid chemotherapy must be regarded as still investigational and potentially quite toxic, further studies are indicated. High dose chemotherapy has been administered in combination with autologous bone marrow rescue. High response rates and prolonged survival durations have been reported in some instances, justifying further study despite substantial toxicity.(ABSTRACT TRUNCATED AT 400 WORDS)

Intrathecal ACNU--a new therapeutic approach against malignant leptomeningeal tumors

Pharmacokinetics, toxicity and therapeutic efficacy of intrathecal ACNU, 3-[4-amino-2-methyl-5-pyrimidinyl)methyl)-1-(2-chloroethyl)-1-nitroso urea, were studied in rats to determine if it is a new and effective method for the treatment of malignant leptomeningeal tumors. Pharmacokinetics of intracisternally administered ACNU was studied by macroscopical autoradiography using 14C-labeled ACNU. It was demonstrated that intracisternally administered ACNU distributed in the subarachnoid space and subpial layer of the brain in high concentration and was rapidly eliminated into the systemic circulation. The diffusional transport of ACNU into the deeper part of the brain was limited. More than 3.0 mg/kg of intracisternal ACNU induced progressive loss of the weight of body in normal rats, and 80% of the rat given 6.0 mg/kg died. Increase of capillary permeability, neuronal loss and gliosis were observed in the marginal layer of the brain facing to the subarachnoid space in the rat given more than 3.0 mg/kg of ACNU. Systemic and local toxicity was not observed in the rat given less than 1.5 mg/kg. Therapeutic effect of intrathecal ACNU against leptomeningeal tumors was evaluated in the rat with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells. The median survival time of the rat treated with 1.5 mg/kg of intracisternal ACNU once on day 2 or on day 5 after tumor inoculation was significantly prolonged by 173%, and 214% at maximum, respectively, as compared with that of the untreated animal. These findings suggest that intrathecal ACNU may be of value for clinical trial against leptomeningeal tumors.

Chemotherapy for malignant gliomas

There continues to be an extensive effort to develop chemotherapeutic approaches to the treatment of malignant gliomas of the brain. In the past 5 years there have been literally hundreds of trials of new agents, combinations of old and new agents, and even new routes and approaches to the delivery of chemotherapy. In this review, the literature has been studied and the individual reports analyzed to evaluate the impact of the new findings on clinical management of the patient with malignant glioma of the brain. The major areas of progress include the addition of new drugs with varying modes of action, the use of combinations of drugs in a synergistic fashion, and the development of new routes of drug delivery. None of the advances has brought about the revolution in clinical care that is so eagerly sought, but clearly the amount of new knowledge gained by these studies helps in understanding how to use chemotherapy more effectively. Furthermore, the remarkable degree of interest and involvement in the use of chemotherapy promises that an even greater number of patients with malignant gliomas will be considered for vigorous and enthusiastic clinical management programs even if chemotherapy itself is not the key modality in the treatment of a specific patient.