Comparison between BCNU and procarbazine chemotherapy for treatment of gliomas

A phase II trial of thalidomide and procarbazine in adult patients with recurrent or progressive malignant gliomas

Thalidomide and procarbazine have demonstrated single agent activity against malignant gliomas (MG). We evaluated the combination of thalidomide and procarbazine with a single arm phase II trial in adults with recurrent or progressive MG. Procarbazine was given at a dose of 250 mg/m(2)/d × 5day q 28 days. Thalidomide was administered at a dose of 200 mg/day continuously. Intrapatient dose escalation of thalidomide was attempted (increase by 100 mg/day weekly as tolerated) to a maximum of 800 mg/day. The primary outcome was tumor response, assessed by MRI and CT. Secondary outcomes were progression free survival (PFS), overall survival (OS) and toxicity. In addition, quality of life questionnaires were performed at baseline and prior to each odd cycle in all treated patients. Eighteen patients (median age of 50) were accrued and received a total of 36 cycles (median 2) of therapy. The median maximum thalidomide dose achieved was 400 mg (range 0-800). No complete or partial responses were seen. One patient (6%) experienced stable disease, fourteen (78%) progressed as best response and three (17%) were not evaluable for response. Median time to progression was 2.1 months (95% CI, 1.5-2.5). Seventeen patients have died (one patient lost to follow-up after progression); median survival from enrollment was 7.6 months (95% CI, 3.5-9.4). Grade 3/4 drug related toxicity was minimal. Quality of life diminished over time. The combination of thalidomide and procarbazine demonstrated no efficacy in this trial.

In vitro drug response and molecular markers associated with drug resistance in malignant gliomas

PURPOSE

Drug resistance in malignant gliomas contributes to poor clinical outcomes. We determined the in vitro drug response profiles for 478 biopsy specimens from patients with the following malignant glial histologies: astrocytoma (n = 71), anaplastic astrocytoma (n = 39), glioblastoma multiforme (n = 259), oligodendroglioma (n = 40), and glioma (n = 69).

EXPERIMENTAL DESIGN

Samples were tested for drug resistance to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), cisplatin, dacarbazine, paclitaxel, vincristine, and irinotecan. Biomarkers associated with drug resistance were detected by immunohistochemistry, including multidrug resistance gene-1, glutathione S-transferase pi (GSTP1), O(6)-methylguanine-DNA methyltransferase (MGMT), and mutant p53.

RESULTS

In vitro drug resistance in malignant gliomas was independent of prior therapy. High-grade glioblastomas showed a lower level of extreme drug resistance than low-grade astrocytomas to cisplatin (11% versus 27%), temozolomide (14% versus 27%), irinotecan (33% versus 53%), and BCNU (29% versus 38%). A substantial percentage of brain tumors overexpressed biomarkers associated with drug resistance, including MGMT (67%), GSTP1 (49%), and mutant p53 (41%). MGMT and GSTP1 overexpression was independently associated with in vitro resistance to BCNU, whereas coexpression of these two markers was associated with the greatest degree of BCNU resistance.

CONCLUSIONS

Assessment of in vitro drug response and profiles of relevant tumor-associated biomarkers may assist the clinician in stratifying patient treatment regimens.

Recurrent glioblastoma multiforme: advances in treatment and promising drug candidates

Recurrent glioblastoma multiforme is a lethal disease with currently available treatment options having a limited impact on outcome. In this article, current and novel therapeutic approaches in the treatment of recurrent glioblastoma multiforme, including chemotherapy, targeted molecular agents, virotherapy/gene therapy and immunotherapy and challenges in developing novel therapeutic agents for glioblastoma multiforme will be discussed.

Chemotherapy in the treatment of malignant gliomas

Malignant gliomas are one of the most difficult tumors to treat, with only modest advances being made in the past few decades. Surgery and radiation have had the greatest impact, increasing survival. Chemotherapy modestly increases survival. The use of chemotherapy in the treatment of malignant gliomas is the focus of this paper and the more commonly used agents at diagnosis and relapse are reviewed. Since most patients fail first-, second- and even third-line agents that are commercially available, some of the more relevant new biological compounds will also be discussed. As treatments for brain tumors evolve, it is likely that optimal therapies will come from combination therapies that incorporate target-specific and chemotherapeutic agents.

A phase II window trial of procarbazine and topotecan in children with high-grade glioma: a report from the children’s oncology group

The role of chemotherapy in the treatment of high-grade gliomas in children is unclear. Early reports were suggestive of improved outcome in children with high-grade glioma with the addition of chemotherapy after surgery and radiation therapy. Subsequent studies did not show similar favorable contribution of chemotherapy to the outcome of these children. Further efforts to identify active chemotherapy agents in children include use of agents that have shown efficacy in adult patients with high-grade glioma and agents that have shown promise in mice bearing human xenografts of brain tumors. A Pediatric Oncology Group (POG 9431) trial tested the activity of two such agents, procarbazine and topotecan in newly diagnosed patients with high-grade glioma who had measurable disease after diagnostic surgery. Neither agent showed efficacy within the confines of the statistical design of the study. This study showed that children with high-grade glioma have an innate resistance to alkylating agents based on mismatch repair deficiency and high levels of alkyguanine transferase (AGT). Future trials should consider strategies to overcome the resistance mechanisms in children with high-grade glioma.

High-dose BCNU followed by autologous hematopoietic stem cell transplantation in supratentorial high-grade malignant gliomas: a retrospective analysis of 114 patients

Conventional treatment of high-grade glioma includes maximal surgical resection followed by external radiation therapy. Despite this treatment, the prognosis for patients is poor. High doses of chemotherapy might be another way to increase the response rate and median survival. Increasing doses of BCNU might be more effective, but also provokes unacceptable myelotoxicity. This dose-limiting toxicity can be circumvented by using autologous blood stem cell rescue. We report our experience of high-dose BCNU followed by transplantation of autologous hematopoietic stem cells in 114 patients with high-grade gliomas. Of the 114 gliomas, 78 were glioblastoma multiforme (GM) (68%), 24 anaplastic astrocytomas (AA) (21%), and 12 anaplastic oligodendrogliomas (OD) (11%). Complete surgical resection was performed for 22 patients (18 GM and 4 AA). The median age was 44 years (range 17-65). A total of 84 patients received autologous hematopoietic stem cells from bone marrow harvest, while 30 patients received granulocyte colony-stimulating factor followed by apheresis and received peripheral blood progenitor cells (PBPC). High dose of BCNU (800 mg/m(2)) was given at least 1 month after neurosurgery. Bone marrow or PBPC was transplanted 48-72 h after chemotherapy. Radiotherapy was started approximately 40 days after transplantation to a total of 60 Gy. Median follow-up was 89 months (19-163). The overall survival (OS) was, respectively, 12 months for GM, 37 months for OD and 81 months for AA. Histological type appeared to be the main discriminating factor, with a worse prognosis for GM. Within the GM population, age, completeness of surgery, and response appeared to be one important prognostic factors. The AA and OD populations were small to reliably assess prognostic factors. On multivariate analysis, the main prognostic factors were histologic type, quality of surgery, and age (P<0.005). Five of 114 patients had lethal complications from the procedure. Four of these patients had a Karnovsky performance score (KPS) of 60%. The protocol thus appears to be feasible but patients should be selected for KPS more than 70%. We observed long-term survivors, although the OS and the time to treatment failure seem to be comparable to that described for other treatment. Additional pilot studies are unlikely to reveal more than a modest benefit from this procedure and therefore a randomized study should be performed.

A multidrug combination designed for reversing resistance to BCNU in glioblastoma multiforme

BACKGROUND

Nitrosoureas constitute the main resource of chemotherapy for glioblastoma. However, because of chemoresistance, which is intrinsic or rapidly acquired after the first administration of chemotherapy, there have been few improvements in survival. Because O(6)-alkylguanine-DNA alkyltransferase (AGT) is the main target for increasing cell sensitivity to the nitrosoureas, we postulated that preexposure to other alkylating agents might increase the therapeutic index of the nitrosoureas by saturating all the copies of AGT present in the tumor cells.

OBJECTIVE

To investigate the response rate, toxic effects, time from start of chemotherapy to progression of disease or exit from the study for any reason (TTP), and progression-free survival at 6 months (PFS-6) associated with a multidrug combination that could reverse resistance to carmustine (BCNU) through AGT depletion.

METHODS

We conducted a phase 2 study of patients with glioblastoma at first relapse or progression after surgery and standard radiotherapy. Patients were treated with 100 mg/m(2) of procarbazine on days 1 to 5, 80 mg/m(2) of BCNU on days 3 to 5, and 1.4 mg/m(2) of vincristine on day 3 every 8 weeks.

RESULTS

Fifty-eight patients were enrolled in the study, and all were assessable for response and toxic effects. Six patients (10.3%) had a complete response, 11 (19%) had a partial response, and 17 (29.3%) had stable disease. The median TTP was 4.8 months; 42.3% of patients had PFS-6, and 15.4% had PFS at 12 months. Response to chemotherapy was the only significant prognostic factor for TTP. Neutropenia was grade 3 in 8.6% of patients and grade 4 in 5.2% of patients, and thrombocytopenia was grade 3 in 17.2% of patients and grade 4 in 12% of patients; hepatic and pulmonary toxic effects were grade 3 in 5.2% and 8.6% of patients, respectively.

CONCLUSION

This regimen proved active in chemotherapy-naive patients with recurrent glioblastoma even though toxic effects were substantial.

Fotemustine combined with procarbazine in recurrent malignant gliomas: a phase I study with evaluation of lymphocyte 06-alkylguanine-DNA alkyltransferase activity

The aims of this phase I study in patients with recurrent malignant gliomas were to determine the maximum tolerated dose (MTD) and toxicity profile of fotemustine when combined with a fixed dose of procarbazine (PCZ), and to evaluate the extent of O6-alkylguanine-DNA alkyltransferase (ATase) depletion in circulating lymphocytes during treatment. Sixteen patients received an induction cycle consisting of 100 mg/day oral PCZ for 12 consecutive days and a 1-h intravenous infusion of fotemustine given 4 h after PCZ on days 5 and 12 at escalated doses (50, 75, 100 and 125 mg/m2/day). After a 6-week rest period, a maximum of 4 maintenance cycles (PCZ 300 mg/day, 4 days; fotemustine, day 4) was given every 4 weeks. ATase activity was measured on days 1, 5 and 12 over 4 h after PCZ intake. Fifteen patients had previously received at least one nitrosourea-based chemotherapy, associated with PCZ in 12 cases. The MTD of fotemustine was 125 mg/m2 (days 5 and 12) with myelosuppression as the dose limiting toxicity (DLT). At this dose level, half of patients experienced grade 3 anemia, neutropenia or thrombopenia. No extra-hematological DLT was observed. No significant depletion of ATase activity by PCZ was evidenced. One partial response and 7 stable diseases were obtained leading to a disease control rate of 50%. The median times to progression and survival were 2.6 and 9.7 months, respectively. This combined regimen of PCZ and fotemustine was well tolerated with a good disease control rate in heavily pretreated glioma patients and merits further investigation in phase II studies.

Brain tumors in the older person

BACKGROUND

The incidence of brain tumors is increasing rapidly, particularly in the older population. Advances in molecular biology help to explain differences in biologic behavior and response to therapy of brain tumors in the elderly compared with younger patients. The number of elderly patients who desire and receive therapy for brain tumors and are included in clinical trials is increasing.

METHODS

This article reviews the literature on the epidemiology, clinical aspects, and therapy of brain tumors, with emphasis on the older patient population.

RESULTS

The increased incidence of brain tumors in the elderly is principally due to the increasing number of people who comprise the older population. Age and performance status are important independent prognostic indicators, together with tumor histology. Surgery, radiation therapy, and chemotherapy can benefit elderly patients with brain tumors with favorable histologies, tumor location, and good performance status. The response rates to available therapies are less favorable than in younger patients, and only a small number of elderly patients are enrolled in clinical studies addressing new treatment modalities.

CONCLUSIONS

Brain tumors in the elderly have specific characteristics that determine their biologic behavior and response to therapy. There is a need for clinical studies designed for treatment of brain tumors in older patients, and requirements for rehabilitation and support systems for the elderly need to be addressed.

Clinical presentation, diagnosis, and pharmacotherapy of patients with primary brain tumors

OBJECTIVE

To briefly review the clinical presentation and diagnosis of patients with primary brain tumors, followed by an in-depth survey of the pertinent pharmacotherapy.

DATA SOURCES

A detailed search of the neurologic, neurosurgical, and oncologic literature for basic science research, clinical studies, and review articles related to chemotherapy and pharmacotherapy of primary brain tumors.

STUDY SELECTION

Relevant studies on tissue culture systems, animals, and humans examining the mechanisms of action, pharmacokinetics, clinical pharmacology, and treatment results of chemotherapeutic agents for primary brain tumors. In addition, studies of pharmacologic agents administered for supportive care and symptom control are reviewed.

DATA SYNTHESIS

Primary brain tumors derive from cells within the intracranial cavity and generally present with headache, seizure activity, cognitive changes, and weakness. They are diagnosed most efficiently with magnetic resonance imaging. After diagnosis, the most common supportive medications include corticosteroids, gastric acid inhibitors, and anticonvulsants. Chemotherapy is adjunctive treatment for patients with malignant tumors and selected recurrent or progressive benign neoplasms. In general, the most effective chemotherapeutic drugs are alkylating agents such as the nitrosoureas, procarbazine, cisplatin, and carboplatin. Other agents used include cyclophosphamide, methotrexate, vincristine, and etoposide. Angiogenesis inhibitors and gene therapy comprise some of the novel therapeutic strategies under investigation.

CONCLUSIONS

The efficacy of chemotherapy for primary brain tumors remains modest. Novel agents must be discovered that are more specific and attack tumor cells at the molecular level of tumorigenesis. Furthermore, strategies must be developed to counteract the pervasive problem of brain tumor chemoresistance.

Procarbazine and high-dose tamoxifen as a second-line regimen in recurrent high-grade gliomas: a phase II study

PURPOSE

A phase II study was conducted in patients with high-grade gliomas that recurred after surgery plus radiotherapy and a first-line nitrosourea-based regimen. Our aim was to investigate the efficacy of procarbazine (PCB) combined with high-dose tamoxifen in relation to tumor control, toxicity, and time to progression (TTP).

PATIENTS AND METHODS

Fifty-three patients were treated with procarbazine in repeated 30-day courses at 100 mg/m2/d plus tamoxifen 100 mg/d, with a 30-day interval between courses. Thirty-four patients had been pretreated with a first-line nitrosourea-based chemotherapy regimen (group A), and 19 patients had also been pretreated with a second-line chemotherapy regimen consisting of carboplatin and teniposide (group B). Twenty-one of the patients had also been procarbazine pretreated, whereas the remaining 32 patients were not procarbazine pretreated.

RESULTS

The response was assessed in 51 patients, 28 of whom had glioblastoma multiforme (GBM) and 23 of whom had anaplastic astrocytoma (AA). There were two complete responses (CR) (4%) and 13 partial responses (PR) (25.5%). The overall response rate (CR + PR) was 29.5% (SE, 6.4; 95% confidence interval [CI], 23 to 35.8). Seventeen patients (32%) had stable disease (SE, 6.2; 95% CI, 21 to 33.6). The median TTP was 13 weeks for patients with GBM and 33 weeks for patients with AA (P = .006). The median survival time (MST) was 27 weeks for patients with GBM and 57 weeks for those with AA (P = .006).

CONCLUSION

Combined PCB and tamoxifen as a second-line regimen gave a reasonably high response rate in patients with heavily pretreated high-grade gliomas. However, although it resulted in an improvement in the patients' quality of life and/or performance status, it was not followed by an increased TTP or MST.

Treatment of recurrent malignant supratentorial gliomas with ifosfamide, carboplatin and etoposide: a phase II study

Thirty-six patients previously treated with surgery, radiation therapy and chemotherapy with a nitrosourea for malignant supratentorial gliomas received a combination of ifosfamide, carboplatin and etoposide (ICE) at tumour progression. Carboplatin and etoposide were both given at a dose of 75-100 mg/m2/day for 3 days, whereas ifosfamide doses ranged from 750 mg/m2/day to 1500 mg/m2/ day for 3 days, according to haematological tolerance. Treatment was repeated every 4 weeks. A minimum of three courses was required to evaluate the response unless the patient had rapid tumour progression. Grade III and IV haematological toxicity occurred in 15 patients (42%) and was lethal in one patient. Grade II hepatic toxicity was observed in one patient. Five complete (CR) and five partial responses (PR) were noted. 9 patients had stable disease (SD) after a minimum of three courses. CR + PR + SD was 53% (19/36). The median time to tumour progression (MTTP) was 13 weeks. Median survival (MST) was 29 weeks (44 weeks for R + S patients and 17 weeks for patients with progressing disease). This study suggests that the ICE combination is active in recurrent supratentorial malignant gliomas after failure of surgery, radiation therapy and chemotherapy, but at the cost of substantial haematological toxicity.

Attempted dose intensified cyclophosphamide, etoposide, and granulocyte colony-stimulating factor for treatment of malignant astrocytoma

Patients with malignant astrocytoma continue to respond poorly to chemotherapy and have a dismal prognosis. Cyclophosphamide (CTX) and etoposide demonstrate activity against malignant astrocytoma at standard dosages, with bone marrow suppression as the limiting toxicity. In order to allow dose intensification, minimize leukopenia, and improve efficacy granulocyte colony-stimulating factor (G-CSF) was used in combination with CTX and etoposide. The protocol consisted of CTX (2 mg/m2/d, days 1, 2), etoposide (200-300 mg/m2/d, days 1-3), and G-CSF (5-10 micrograms/d subcutaneously, days 4-18), every 4 weeks. Nine evaluable patients (7 glioblastoma multiforme, 2 anaplastic astrocytoma) were treated, ranging in age from 26-67 (mean 41). One of 9 patients responded (11%) with a partial response (13+ months), 3 had stable disease (33%; 8, 5, 2.5 months), and 5 had progressive disease (3, 2.5, 2, 1.5, 1 months). The median time to progression for responders was 6.5 months, while overall it was 2.5 months. Overall median survival was only 7.0 months. Toxicity was frequent and severe, typically delaying treatment cycles. The most common complications were severe myeolosuppression (9), sepsis (8), rash (6), urinary infection (5), and anorexia (5). Treatment delays caused by infections and other complications occurred often, abrogating the intended dose intensification. The received dose intensity (DI) for CTX was 400-425 mg/m2/week (relative DI 0.41), while for etoposide it was 75 mg/m2/week (relative DI 0.42). In summary, as used in this protocol, dose intensive chemotherapy with CTX, etoposide, and G-CSF does not improve efficacy over standard regimens and results in excessive toxicity.