Search

The objective of this retrospective study was to report treatment outcomes in dogs with histiocytic sarcoma (HS) that were treated with nimustine (ACNU). This study evaluated data from 11 dogs including 5 with macroscopic tumors that were treated in the primary setting and 6 that underwent aggressive local therapy while being treated in the adjuvant setting. The median ACNU starting dose was 25 mg/m 2 (range, 20-30 mg/m 2 ; 3- to 5-wk intervals, 1-8 administrations). The median overall survival in the primary and adjuvant settings was 120 days (median progression-free survival [PFS], 63 days) and 400 days (median PFS, 212 days), respectively. Neutropenia was observed in eight cases (grade 1, n = 1; grade 2, n = 2; grade 3, n = 2; grade 4, n = 3) with nadir neutrophil count at 1 wk after ACNU administration. Mild gastrointestinal toxicity (grade 1-2) was observed in three cases. ACNU was well tolerated and showed a similar outcome to that seen for lomustine, which is a drug commonly used to treat canine HS, in terms of overall survival and PFS in the current study population. Further investigations will need to be undertaken to definitively determine if ACNU is an appropriate alternative to lomustine for the treatment of HS.

Purpose: A major adverse effect arising from nimustine hydrochloride (ACNU) therapy for brain tumors is myelosuppression. Because its timing and severity vary among individual patients, the ACNU dose level has been adjusted in an empiric manner at individual medical facilities. To our knowledge, ours is the first study to develop a machine-learning approach to estimate myelosuppression through analysis of patient factors before treatment and attempts to clarify the relationship between myelosuppression and hematopoietic stem cells from daily clinical data. Adverse effect prediction will allow ACNU dose adjustment for patients predicted to have decreases in blood cell counts and will enable focused follow-up of patients undergoing chemoradiotherapy., Patients and Methods: Patients were newly pathologically diagnosed with WHO grade 2 or 3 tumors and were treated with ACNU-based chemoradiotherapy. For detailed analysis of the timing and intensity of adverse effects in patients, we developed a data-weighted support vector machine (SVM) based on adverse event criteria (nadir-weighted SVM [NwSVM]). To evaluate the estimation accuracy of blood cell count dynamics, the determination coefficient ( r 2 ) between real and estimated data was calculated by three regression methods: polynomial, SVM, and NwSVM., Results: Only the NwSVM-based regression enabled estimation of the dynamics of all blood cell types with high accuracy (mean r 2 = 0.81). The mean timing of nadir arrival estimated using this regression was 35 days for platelets, 41 days for RBCs, 52 days for lymphocytes, 57 days for WBCs, and 62 days for neutrophils., Conclusion: The NwSVM can be used to predict myelosuppression and clearly depicts nadir timing differences between platelets and other blood cells.

Rationale: Small cell lung cancer (SCLC) characterized by high degree of malignancy and rapid tumor progression. Intracranial metastases often appear at the time of the initial diagnosis or treatment. Besides of radiotherapy, chemotherapy is supposed to have limited effect., Patient Concerns: A 66-year-old male had blurred vision and unsteady step with moderate headache, nausea, vomit., Diagnoses: The patient was diagnosed with SCLC with intracranial metastases., Interventions: High dose of nimustine (ACNU) (300 mg/m) add to the regimen containing carboplatin and irinotecan., Outcomes: Although the patient suffered severe myelosuppression, the intracranial lesion almost disappeared and maintained half a year., Lessons: ACNU at a dose of 200 mg/m might be tolerable in combination with other chemotherapeutic drugs for the treatment of SCLC with intracranial metastases besides radiotherapy.

Nimustine (ACNU) is an alkylating agent of the nitrosourea and can be an antineoplastic agent in dogs. But, there has been no report on its dose-limiting toxicity (DLT) in dogs. This study was a phase I dose-escalation clinical trial to determine the maximum tolerated dose (MTD) and DLT of ACNU in tumor-bearing dogs. The starting dosage was 25 mg/m(2), and subsequent dosages were administered in increments of 5 mg/m(2) in cohort of 3 dogs. Eight dogs were included, the MTD was determined to be 25 mg/m(2), DLT was neutropenia, and the optimal interval was considered to be 21 days. The data herein provide a basis for the subsequent phase II trial of ACNU in dogs.

Although temozolomide (TMZ) replaced nitrosoureas as the standard initial chemotherapy for glioblastoma (GBM), no studies have compared TMZ with nimustine (ACNU), a nitrosourea agent widely used in central Europe and most Asian regions. One hundred thirty-five patients with GBM who underwent extensive tumor resection in our institution received both radiation and chemotherapy as initial treatment, 34 received TMZ and 101 ACNU-based (ACNU plus teniposide or cisplatin) chemotherapy. Efficacy analysis included overall survival (OS) and progression-free survival (PFS). The following prognostic factors were taken into account: age, performance status, extent of resection, and O(6)-methylguanine-DNA-methyltransferase (MGMT) gene status. The median OS was superior in the TMZ versus the ACNU group (p = 0.011), although MGMT gene silencing, which is associated with a striking survival benefit from alkylating agents, was more frequent in the ACNU group. In multivariate Cox analysis adjusting for the common prognostic factors, TMZ chemotherapy independently predicted a favorable outcome (p = 0.002 for OS, hazard ratio [HR], 0.45; p = 0.011 for PFS, HR, 0.56). Given that >40 % of patients in ACNU group did not receive the intensive chemotherapy cycles because of severe hematological and nonhematological toxicity, we performed a further subanalysis for patients who received at least 4 cycles of chemotherapy. Although a modest improvement in survival occurred in this ACNU subgroup, the efficacy was still inferior to that in the TMZ cohort. Our data suggest that the survival benefit of TMZ therapy is superior to that of an ACNU-based regimen in patients with extensive tumor resection, also shows greater tolerability.

Recently, local chemotherapy proved its efficacy against malignant gliomas. Under the hypothesis that local delivery of chemotherapeutic agents into the brain parenchyma induce opening of the blood-brain barrier (BBB), we evaluated the opening of BBB after convection-enhanced delivery of nimustine hydrochloride into the brain parenchyma. Local convection-enhanced delivery of nimustine hydrochloride transiently opened the BBB from about 7-12 days after delivery in normal rodent brain. Systemic chemotherapy during this period of BBB disruption had synergistic effects resulting in prolonged survival of tumor-bearing rats. The present strategy may provide a new approach for glioma chemotherapy., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

This 13-year-old boy with a history of cranial irradiation for the CNS recurrence of acute lymphocytic leukemia developed a glioblastoma in the right cerebellum. Resection and chemo- and radiotherapy induced remission of the disease. However, recurrence was noted in the brainstem region 8 months later. Because no effective treatment was available for this recurrent lesion, the authors decided to use convection-enhanced delivery (CED) to infuse nimustine hydrochloride. On stereotactic insertion of the infusion cannula into the brainstem lesion, CED of nimustine hydrochloride was performed with real-time MR imaging to monitor the co-infused chelated gadolinium. The patient's preinfusion symptom of diplopia disappeared after treatment. Follow-up MR imaging revealed the response of the tumor. The authors report on a case of recurrent glioblastoma infiltrating the brainstem that regressed after CED of nimustine hydrochloride.

Therapy-related myelodysplastic syndrome (t-MDS) is mostly attributed to chemotherapeutic agents of alkylating agents. Few studies have evaluated the late effects of chemotherapy for malignant melanoma (MM). To evaluate whether dacarbazine, nimustine hydrochloride and vincristine sulfate (DAV) therapy for MM related to t-MDS or not, a retrospective analysis was performed. We conducted a retrospective case-control study in a cohort of the 217 patients diagnosed with MM from 1989-2007 in Aichi Medical University Department of Dermatology and Nagoya University Graduate School of Medicine Department of Dermatology. One hundred and fifty-five of the 217 patients with MM were prospectively followed after DAV therapy or with or without local injection of β-interferon, of whom two patients developed t-MDS. Cytogenetic abnormalities were found in two of the 35 patients by chromosome banding method - leukemia (G-Banding). The karyotypes were found in the chromosome of -5, deletion (5), addition (7) and 7q-. In conclusion, DAV therapy should be used carefully for older patients with MM after satisfactory operation., (© 2010 Japanese Dermatological Association.)

Aims and Background: Glioblastoma has a poor prognosis, with few therapeutic options if it recurs. We report a case in which we were able to inhibit the growth of a recurrent glioblastoma by weekly single-dose administration of interferon-beta., Case Report: A patient with recurrent glioblastoma after radiation and chemotherapy was treated with nimustine and interferon-beta. After 2 cycles of nimustine, the patient's leukocyte, neutrophil, and platelet counts showed grade 4 toxicity according to the National Cancer Institute's Common Toxicity Criteria. The patient was treated with a weekly single dose of interferon-beta at 6 x 10(6) IU. The tumor showed no remarkable changes after 18 months, and the patient's Karnofsky performance status remained at 50%., Conclusions: The administration of interferon-beta produced long-term control in one case of glioblastoma and may be an effective therapy.

Myelotoxicity is a dose-limiting effect of many chemotherapeutic regimens. Thus, there is great interest in protecting human hematopoietic stem cells by the transfer of drug resistance genes. The main focus of this study was the simultaneous overexpression of multidrug resistance 1 (MDR1) and the O(6)-benzylguanine (O(6)-BG)-resistant mutant MGMT(P140K) (O(6)-methylguanine-DNA methyltransferase) with a bicistronic lentiviral vector (HR'SIN-MDR1-IRES-MGMT(P140K)), with regard to the capability to convey chemoprotection in the leukemia cell line, HL60, and human hematopoietic stem cells (CD34(+)). Combination therapy with O(6)-BG/1-(2-chloroethyl)-3-(4-amino-2-methylpyrimidine-5-yl)methyl-1-nitrosourea) (ACNU) plus paclitaxel showed a significant survival advantage of HL60 cells transduced with this combination vector. In CD34(+) cells, monotherapy with O(6)-BG/temozolomide (TMZ) resulted in an increased percentage of MGMT-positive cells (vs untreated cells) after transduction with HR'SIN-MDR1-IRES-MGMT(P140K) (28.3%). For combination therapy with O(6)-BG/temozolomide plus paclitaxel the increase was higher with the combination vector (52.8%) than with a vector expressing MGMT(P140K) solely (29.1%). With regard to MDR1-positive cells the protective effect of the combination vector (88.5%) was comparable to the single vector HR'SIN-MDR1 (90.0%) for monotherapy with paclitaxel and superior for combination therapy with O(6)-BG/temozolomide plus paclitaxel (84.6 vs 69.7%). In conclusion, the combination vector presents simultaneous protective effects of two drug-resistance genes, offering an opportunity to increase the cancer therapeutic index.

Purpose: Bi-weekly administrations of nimustine hydrochloride (ACNU) plus paclitaxel were evaluated in this phase II study in patients with refractory small cell lung cancer (SCLC)., Methods: Patients who had disease progression within 3 months after treatment with irinotecan (CPT-11)-containing regimens were entered. They were treated with every other week administrations of ACNU 50 mg/m(2) plus paclitaxel 110 mg/m(2) on day 1 over 2 weeks., Results: Twenty-four patients (20 males and 4 females, median age of 64 years, 17 patients with Eastern Cooperative Oncology Group [ECOG] performance status [PS] 0-1 and 7 patients with PS 2) participated in the trial. Of the 24 refractory patients after CPT-11 containing regimens, 17 patients had been given etoposide plus platinum. There were six partial responses, and an overall response rate of 25% (95% confidence interval, 10-46%) was obtained. The median time to progression and the median survival time after enrollment into this study were 2.8 and 5.8 months, respectively. The median overall survival from the first-line treatment was 19.5 months. The major toxicity was myelosuppression. Grade 4 neutropenia occurred in 13% of patients, and Grade 4 thrombocytopenia was observed in 13% of patients. There was one treatment-related death, attributed to pneumonitis., Conclusion: Bi-weekly administrations of ACNU plus paclitaxel provided a practical and well-tolerated regimen that was active for CPT-11-refractory SCLC.

Background: In a previous trial (NOA-01), the combination of nimustine and teniposide showed efficacy in previously untreated glioblastoma (GBM). After establishing temozolomide as standard first-line therapy in GBM patients, the nimustine (ACNU)/teniposide (VM-26) combination has been employed as salvage chemotherapy for recurrent GBM. However, data on the toxicity and efficacy of this regimen in recurrent GBM are lacking., Patients and Methods: In two neurooncological centers, all patients with recurrent GBM treated with nimustine (90 mg/m(2), day 1/42) and teniposide (45-70 mg/m(2), days 1-3/42) were analyzed retrospectively for progression-free survival (PFS), overall survival (OS) and toxicity., Results: Thirty-five patients (median age 51 years, range 25-71 years) were identified. Six months after chemotherapy initiation, PFS was 29% and the median OS 6 months; 23% of patients were alive > or = 1 year after initiation of nimustine-teniposide chemotherapy. Grade 4 hematotoxicity was observed in 12 of 35 patients (34%) and in 14 of 83 evaluable chemotherapy courses (17%)., Conclusions: The benefit of the nimustine-teniposide combination is moderate in patients with recurrent GBM. The data support the efficacy of the nimustine-teniposide chemotherapy, but the rate of high-grade hematotoxicity is increased., (Copyright 2009 S. Karger AG, Basel.)

Even though past studies have suggested efficacy of nitrosourea drugs in patients with high-grade glioma and temozolomide has recently been shown significantly to be beneficial, no conclusive comparisons between these agents have been published. We performed a survival gain analysis of 364 studies describing 24,193 patients with high-grade glioma treated in 504 cohorts, and compared the effects of drugs. The most frequent diagnoses were glioblastoma multiforme (GBM) (72%) and anaplastic astrocytoma (22%). The mean overall survival (mOS) was 14.1 months. The outcome was influenced by several of the known prognostic factors including the histological grade, if the tumors were newly diagnosed or recurrent, the completeness of resection, patients' age, and gender. This information allowed the calculation of a predicted mOS for each cohort based on their prognostic factors independent of treatment. Survival gain to characterize the influence of treatment was subsequently defined and validated as the difference between the observed and the predicted mOS. In 62 CCNU-treated cohorts and 15 ACNU-treated cohorts the survival gain was 5.3 months and 8.9 months (P < 0.0005), respectively. No detectable survival gain for patients treated with various BCNU-containing regimens was found. Conclusion CCNU- and ACNU-containing regimens were superior to BCNU containing regiments.

Background: Despite intensive multimodal treatment, outcome of patients with malignant glioma remains poor, and a standard dose of radiotherapy for anaplastic astrocytoma has not been defined. In the past RTOG study (83-02), the arm of 72 Gy hyperfractionated radiotherapy (HFRT) for malignant gliomas showed better outcome than the arms of higher doses (76.8 - 81.6 Gy) and the arms of lower doses (48 - 54.4 Gy). The purpose of this study is to verify the efficacy of this protocol., Methods: From July 1995, 44 consecutive eligible patients with histologically proven anaplastic astrocytoma were enrolled in this study (HFRT group). The standard regimen in this protocol was post-operative radiotherapy of 72 Gy in 60 fractions (1.2 Gy/fraction, 2 fractions/day) with concurrent chemotherapy (weekly ACNU). The primary endpoint was local control rate (LCR), and the secondary endpoints were overall survival (OS), progression-free survival (PFS) and late toxicity., Results: Three-year OS of the HFRT group was 64.8% (95% confidence interval; 48.4-81.3%). Three-year PFS rate and LCR were 64.4% (95%CI: 48.4-80.3%) and 81.6% (95%CI: 69.2-94.8%), respectively. The number of failures at 5 years in the HFRT group were 14 (32%). The number of failures inside the irradiation field was only about half (50%) of all failures. One (2%) of the patients clinically diagnosed as brain necrosis due to radiation therapy., Conclusion: The results of this study suggested that 72 Gy HFRT seemed to show favorable outcome for patients with anaplastic astrocytoma with tolerable toxicity.

Object: To assess whether nimustine (ACNU), a drug that can cross the blood brain barrier, combined with radiotherapy, improved the survival of patients with primary central nervous system lymphoma (PCNSL)., Clinical Materials and Methods: Between 1995 and 2005, we treated 63 immunocompetent PCNSL patients with combination therapy consisting of intra-arterial ACNU (100 mg/m(2)) and whole brain radiotherapy (36-50 Gy). Their median age was 60 years (range 28-81). The median follow-up was 24 months., Findings: With this regimen we achieved a complete response rate of 75% (43 of 57 patients). Kaplan-Meier estimates for median progression-free survival and median overall survival were 26 and 39 months, respectively. The 3- and 5-year survival rates were 51% (95% confidence interval [CI], 36-65%) and 32% (95% CI, 17-47%), respectively. By multivariate analysis, age (<60 vs. > or =60 years) was the only statistically significant prognostic factor; the WBRT dose, sex, and number of tumors were not significant prognostic factors in this study. Myelosuppression was the most frequent side effect, 60% of patients experienced grade 3-4 leukopenia. Late neurotoxicity as a result of treatment was observed in 14 of 43 patients (34%) and higher age (>60) was associated with a high risk of neurotoxicity., Conclusion: The intra-arterial administration of ACNU combined with radiation therapy yielded a high response rate at acceptable toxicity levels in younger patients with PCNSL. However, late neurotoxicity was a serious complication in patients above 60 years of age.

We retrospectively evaluated early and long-term complications of an intensified conditioning regimen consisting of busulfan and etoposide in combination with either nimustine hydrochloride (ACNU) (BVA regimen, n = 18) or melphalan (BVL regimen, n = 34) in 52 children with acute leukemia or non-Hodgkin's lymphoma. With a median follow-up of 13.2 years after the BVA regimen and 8.1 years after the BVL regimen, 61% and 76% of patients, respectively, are in continuous complete remission. Transplantation-related mortality was 17% and 6% after the BVA and BVL regimens, respectively, and the corresponding relapse rates were 17% and 15%. The most common and severe toxicity was pulmonary complication in the BVA regimen, which was seen in 67% of patients and was life-threatening in 20%. Thirty-three percent of patients after the BVA regimen and 24% after BVL died of relapse or disease progression (n = 9), interstitial pneumonia (n = 2), fungal pneumonia (n = 1), or chronic graft-versus-host disease (n = 2). One of the long-term survivors developed secondary leukemia. A significant decrease in the height standard deviation score of more than 2 SD from diagnosis to the last follow-up was seen in 17% of the patients, with hypothyroidism in 15%, and alopecia in 42%. Because our experience is limited to a small heterogeneous population of patients who mainly underwent transplantation in the first remission, we cannot draw conclusions on the treatment's effectiveness. The BVL regimen is tolerable, however, because no regimen-related death was observed, whereas the BVA regimen is not recommended because of the high incidence of pulmonary complications. The effectiveness of the BVL regimen requires further study.

We undertook a comparative study of Pegfilgrastim vs. Filgrastim after high-dose melphalan and autologous peripheral blood stem cell transplantation (APBSCT) in multiple myeloma (MM) patients. Thirty-seven consecutive patients were randomly assigned to receive a single 6 mg dose of Pegfilgrastim on day 1 post-transplant (n = 18 patients) vs. daily subcutaneous injections of Filgrastim 5 microg/kg (n = 19 patients) starting on day 5 post-transplant. The median duration of grade 4 neutropenia in the Pegfilgrastim and Filgrastim groups was 5 and 6 d, respectively (P = ns). The results for the two groups were also not significantly different for time to neutrophil and platelet recovery, but incidence of febrile neutropenia (61.1% vs. 100%, P = 0.003) and duration of febrile neutropenia (1.5 d vs. 4 d, P = 0.005), were lower in the Pegfilgrastim arm. After initial haematopoietic reconstitution, we observed significantly higher value of leukocytes x 10(9) L on day 15 (6.0 vs. 2.7, P = 0.004), in the Pegfilgrastim group compared with the Filgrastim group. This study shows that a single injection Pegfilgrastim can be used with safety and efficacy similar to those provided by daily injections of Filgrastim and it is associated with a decrease incidence of infectious events after APBSCT in MM patients.

Aim: To evaluate the feasibility, efficacy and toxicity of hyperfractionated radiotherapy and multi-agent chemotherapy, including procarbazine, nimustine (ACNU) and vincristine, in adults with high-grade gliomas., Materials and Methods: Radiotherapy was administered using two fractions per day of 1.2 Gy to a total dose of 72 Gy. The chemotherapy consisted of procarbazine (90 mg/m2 orally, days 1 to 14), ACNU (80 mg/m2 intravenously, day 1) and vincristine (0.5 mg/m2 intravenously, days 1 and 8) and was administered during and after radiotherapy, up to a maximum of four courses., Results: From September 1997 to August 1999, a total of ten patients (five with glioblastoma and five with grade 3 gliomas) were enrolled. All ten patients were able to complete a total dose of 72 Gy hyperfractionated radiotherapy with one course of concurrent chemotherapy. Of eight assessable patients, three (38%) had an objective response, comprising two CR and one PR. The median time to progression was 10.7 months and the median survival time of all patients was 15.0 months. Although grade 4 leukopenia and grade 4 thrombocytopenia occurred in 10% and 10% of all patients, respectively, these were transient and no patients developed neutropenic fever or intracranial hemorrhage. No serious non-hematological or late toxicities occurred., Conclusion: Hyperfractionated radiotherapy and multi-agent chemotherapy using procarbazine, ACNU and vincristine is safe and well tolerated for high-grade gliomas.

Background: In this randomized phase III study, the effectiveness as well as the side-effects of intraarterial [i.a.] (17 patients) versus intravenous [i.v.] (16 patients) ACNU [Nimustine] administration in newly diagnosed glioblastoma, were compared., Patients and Methods: All patients undenwent extensive surgical resection, and both groups were homogeneous for the other known risk factors. Thirty-three patients with glioblastoma were treated with ACNU at the dose of 80-100 mg/m2. Treatment was repeated every 5-8 weeks for a minimum of 2 and maximum of 14 cycles. Total survival time (TST) and to time to progression were chosen as outcome variables., Results and Conclusion: No significant differences in systemic and hematological toxicity between the i.a. and iv. ACNU administration routes were detected. In both groups, tolerance of the procedure was excellent. Analysis of the main outcome measured showed no significant differences between i.a. and i.v. ACNU administration: time to progression was 6 months for i.a. ACNU and 4 months for i.v. ACNU and total survival time was 17 months for i.a. ACNU and 20 months for i.v. ACNU. In spite of ACNU dose incrementation, obtained through i.a. route administration, and subsequent higher concentration in the tumor bed, no improvement could be achieved in effectiveness.

Purpose: To evaluate the activity and the toxicity of ACNU (1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-cholroethyl)-3-nitrosourea hydrochloride) administered with cisplatin by intravenous infusion for 72 h in select patients with recurrent glioblastoma., Patients and Methods: From April 1996 to 2002, 37 patients with histologically proven glioblastoma, who showed recurrence on image study after operation and radiation, met the eligibility criteria of our cohort. The mean time to recurrence was 9.7+/-7.0 (1-26 months). Treatment response was evaluated every 6 weeks using magnetic resonance imaging (MRI). Complete blood counts were collected every week to monitor and treat possible bone marrow suppression from the treatment. Survival rates were analyzed using the Kaplan-Meier and log rank test., Results: Post-chemotherapy MRI was available in 36 of 37 patients. Response to treatment was observed in 19 patients (53%) including two cases of complete remission. Six patients (17%) showed progression (PD) and 11 patients (31%) had stable disease (SD). Two or more cycles of chemotherapy was the only factor that predicted response to treatment. The overall median survival for all patients was 17.0+/-5.5 months. Age (< 40 years) and time to recurrence (>or=1 year) were the clinical factors that predicted improved overall survival. Survival gain after chemotherapy was 9 months. Patients who responded and those with SD after treatment (11 months) had a longer median survival compared to PD (5 months) (P=0.01). Myelosuppression was severe (grade III/IV leukopenia in 15 patients (40%) and grade III/IV thrombocytopenia in 19 patients (52%)) but most recovered more than WHO grade II at the end of the chemotherapy cycles. There was only one fatality due to sepsis from pneumonia during the initial leukopenic state., Conclusion: ACNU and cisplatin chemotherapy can be an effective salvage therapy for recurrent glioblastoma patients. Myelosuppression from the chemotherapy regimen was the greatest side-effect but was manageable.

Purpose: To evaluate the efficacy and toxicity of chemotherapy with ACNU (1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-(2-chloroethyl)-3-nitrosourea) plus cisplatin followed by cranial irradiation in patients with newly diagnosed glioblastoma multiforme., Patients and Methods: Between August 1999 and July 2001, previously untreated 30 patients with histologically confirmed glioblastoma multiforme were treated. Chemotherapy consisting of up to 2 cycles of 72 h of continuous intravenous infusion of ACNU (40 mg/m2/day) and cisplatin (40 mg/m2/d) was given over a 6-week period. Radiation was begun 6 weeks after the second cycle of chemotherapy., Results: Median age was 48 years (range 18-66 years) and 22 patients with residual measurable disease after surgery were eligible for response analysis. One (5%) had a complete response (CR), 36% partial response (PR), 14% stable disease (SD), and 45% progressive disease (PD) after chemotherapy. After additional radiation, 22% had CR, 22% PR, 16% SD, and 42% PD. Grades III and IV leukopenia and thrombocytopenia occurred in 18 cycles (36%) and 15 cycles (30%), respectively. No fatal complications occurred. Median time to progression was 5.9 months (95% CI 5.1-6.8 months) and median overall survival was 14.9 months (95% CI 9.1-20.7 months)., Conclusions: Preradiation chemotherapy with ACNU plus cisplatin is effective and feasible in patients with gliobiastoma multiforme.

This prospective randomized trial was performed to compare the effectiveness of intra-arterial ACNU with intravenous ACNU in newly diagnosed patients with supratentorial glioblastoma. The primary end points were overall survival and progression-free survival. Within 3 weeks after surgery, patients were randomly assigned to receive either intravenous or intra-arterial ACNU (80 mg/m2) once every 6 weeks concomitant with radiotherapy. Intraarterial ACNU was administered for the first 3 courses followed by intravenous administration. Eighty-four patients were enrolled onto this study and among them 82 patients who passed eligibility criteria were analyzed. Patients characteristics were not different significantly between 2 treatment arms. Median survival and progression-free survival time was 59 and 24 weeks, respectively for intra-arterial arm and 56 and 45 weeks, respectively for intravenous arm. There was no significant difference respectively between two treatment arms. Among the prognostic variables including age, Karnofsky performance status, extent of surgery and treatment arm, Cox's proportional hazards model showed that age was the only significant factor for both survival and progression-free survival (P = 0.003 and 0.016, respectively). With regard to toxicity, there was no significant difference between two treatment arms. Leukoencephalopathy was not observed in intra-arterial arm. In conclusion, intra-arterial ACNU when administered by the method in this study does not increase the survival and progression-free survival of newly diagnosed patients with glioblastoma over that afforded by intravenous ACNU.

The de novo leukemic transformation of essential thrombocythemia is a rare event, and usually associated with previous treatments. We describe a patient who received treatments with nitrosourea for long-standing essential thrombocythemia and subsequently developed extramedullary tumors, tentatively diagnosed as lymphoblastic lymphoma. Combination chemotherapy was initially successful, but relapsed with marked bone marrow involvement. Surface marker analysis revealed that the tumor cells had CD5, CD7, CD33, CD34, and CD56 antigens but lacked other T-cell, and B-cell markers. Immunogenotypical studies revealed germline configurations for both T-cell receptors and immunoglobulin genes. These clinical and phenotypical features are consistent with a myeloid/natural killer cell precursor leukemia, a recently proposed distinct clinical entity. To our knowledge, this is the first report of secondary leukemia of myeloid/ natural killer cell precursor origin, and suggest that myeloid/natural killer cell precursor might be a potent target of therapy-related leukemia.

The aim of this study is to describe the authors' experience with intra-arterial ACNU chemotherapy of malignant gliomas. The prognosis of cerebral malignant gliomas remains poor, whatever traditional therapy is applied. ACNU is a well tolerated nitrosourea with a strong antimitotic effect on neurogenic cells both in vitro and in vivo; this drug has enhanced efficacy when used at high concentrations, particularly as an intraarterial infusion. Seventy-six patients have been studied to date, 68 of whom are evaluable; these patients were treated by intra-arterial infusion of ACNU (100 mg/m2) every 6 weeks, with a mean of 2.5 courses per patient. The objective response (OR) was 28% and analysis of pretreatment factors revealed that survival was influenced by histological grade, other types of therapy applied, and age. In general IAC is well tolerated and the response and survival appear to be better than with systemic chemotherapy.

Thirty-three adult patients with anaplastic astrocytoma or glioblastoma multiforme, verified between 1990 and 1997, received postoperative intra-arterial ACNU chemotherapy and irradiation. Since our previous strategies to malignant gliomas had included intra-venous ACNU, the purpose of the present study is to evaluate the advantage of intra-arterial ACNU over its intra-venous counterpart as the historical control (37 patients). The median survival was 74.7 weeks for the former and 81.7 weeks for the latter. Although both groups were equivalent in survival, toxicity was less frequent in the intra-arterial group. Histopathological diagnosis, patient age and the Karnofsky's performance status related well with the survival.

Chloroethylnitrosoureas (CNUs) are being used in the therapy of various neoplastic diseases, including skin cancer. Because secondary tumor formation is a serious threat in chemotherapy with these drugs, we explored whether and to what extent the DNA repair protein DNA-O6-methylguanine:protein-L-cysteine S-methyltransferase (MGMT) protects against CNU-induced tumors. We made use of transgenic mice overexpressing human MGMT in their skin and the initiation-promotion protocol on treatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU, nimustine) that is representative of CNUs. ACNU applied topically as a single low dose to the dorsal skin was highly effective in tumor induction in nontransgenic mice, whereas in cytokeratin MGMT transgenic mice, tumor formation was remarkably reduced. ACNU-induced skin tumors harbored mutations in the c-Ha-ras gene in both groups of mice. The results provide clear evidence that MGMT exerts protection against CNU-induced cancer. Our data also indicate that O6-chloroethylguanine, which is repaired by MGMT, is a main precarcinogenic CNU-induced DNA lesion.

Objective: A derivative of chloroethylnitrosoureas, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), is a drug of choice for the chemotherapy of human malignant brain tumors. However, the cytocidal effect of ACNU is effectively repressed through repair of ACNU-mediated deoxyribonucleic acid lesions by O6-methylguanine-deoxyribonucleic acid methyltransferase (MGMT). Because a variety of human tumors, including brain tumors, contain high levels of MGMT activity, we investigated the effect of antisense ribonucleic acid (RNA) complementary to MGMT messenger RNA on ACNU resistance in tumor cells., Methods: We established a stable ACNU-resistant clone, C6AR, from the rat glioma cell line C6 exposed to a stepwise increasing concentration of ACNU. We transfected a plasmid deoxyribonucleic acid-encoding antisense MGMT RNA under the control of the human metallothionein promoter into C6AR cells and determined the effect of the antisense RNA on ACNU resistance of tumor cells by a colony-forming efficiency assay., Results: C6AR cells expressed abundant MGMT messenger RNA, although the transcription level of the MGMT gene in parental C6 cells was below the lower limits of detection under the same assay conditions. ACNU resistance of C6AR cells was significantly repressed by transfected gene-dependent antisense MGMT RNA expression that resulted in decreased survival of the tumor cells., Conclusion: ACNU resistance resulting from the expression of MGMT in rat glioma cells is significantly overcome by the expression of antisense MGMT RNA. This result suggests that the antisense MGMT RNA system might be a useful strategy for overcoming ACNU resistance in the treatment of intractable malignant gliomas.

We examined the effects of recombinant human thrombopoietin (rhTPO) on myelosuppressive chemotherapy-induced thrombocytopenia in cynomolgus monkeys. After treatment with nimustine (ACNU) on day 0, the monkeys intravenously received rhTPO at a dose of 0.04, 0.2 or 1 microgram/kg/d or monkey's serum once each day from day 1 to day 28. Administration of rhTPO reduced the severity of thrombocytopenia and accelerated the rate of platelet recovery in a dose-dependent fashion. Treatment with the highest rhTPO dose completely prevented thrombocytopenia and stimulated a marked increase in platelet counts over the normal values. Animals treated with ACNU also became neutropenic and slightly anaemic. Administration of rhTPO following ACNU treatment significantly improved neutropenia with increasing doses of rhTPO, but had no effect on anaemia. Compared to the control animals, rhTPO-treated animals exhibited no significant changes in several serum parameters. C-reactive protein concentration and some blood coagulation profiles within the study period. These results suggest a therapeutic efficacy of rhTPO in improving chemotherapy-induced thrombocytopenia.

A 19-year-old male with chronic myelomonocytic leukaemia (CMML) with bone marrow eosinophilia terminating in myeloblastic transformation is described. Before the appearance of CMML, he received a total dose of 2,894 mg of nimustine for the treatment of a pontine glioma over 12 years. Peripheral blood count showed leucocytosis with mature neutrophils and monocytes. Bone marrow smears showed myeloid hyperplasia with increased blasts and abnormal eosinophils and dysplastic features in the myeloid and megakaryocytic cells. A karyotype analysis of the bone marrow cells indicated 46, XY, der(11)t(1;11)(q21;q14). No bcr/abl rearrangement was observed in the cells. He was treated with hydroxyurea to control the leucocyte count, but myeloblastic transformation developed.

Background: Intraarterial chemotherapy with carboplatin for malignant gliomas has been tried recently, but its therapeutic efficacy and toxicity have not yet been elucidated., Methods: We treated patients with malignant glioma by intraarterial chemotherapy using carboplatin, and compared the efficacy as well as the side effects with intraarterial ACNU., Results: Twenty patients were treated with carboplatin (300 mg/m2) and 22 patients were treated with ACNU (80-200 mg/m2). Response (complete remission+partial response) rate for carboplatin was 12.5% compared to 45% for ACNU. Despite higher response rate for ACNU, the difference in the survival curves of the two groups was not significant. Three patients who were treated with high dose (150-200 mg/m2) of ACNU developed hemiparesis and aphasia. Seven patients treated with carboplatin developed 10 incidences of neurotoxicities; two hemiparesis, one aphasia, one blindness, one visual field disturbance, three convulsions, and two developed incidences of disturbances of consciousness., Conclusions: Intraarterial carboplatin was not superior to intraarterial ACNU in achieving remissions, and showed much greater tendency to produce neurotoxicities.

Thirty cases of gliomas treated by surgery, radiotherapy and intra-arterial (IA) ACNU were reviewed with a focus on the late side-effect known as leukoencephalopathy. All cases were classified into three groups; remission (10 cases), regrowth (15 cases) and leukoencephalopathy (5 cases) from their outcome. The average total doses of IA ACNU were 49.8 mg/sqm body surface area in the remission group, 157.3 mg/sqm in the regrowth group and 203.1 mg/sqm in the leukoencephalopathy group. There were significant differences in the total IA ACNU doses between the remission group and both regrowth and leukoencephalopathy groups, while no significant differences were noticed in the dose of radiation given. There was a correlation between the total dose of IA ACNU and the occurrence of leukoencephalopathy. An autopsy of a typical case of leukoencephalopathy revealed various degrees of myelin breakdown and thickening of arterial walls, which probably manifested progressive dementia accompanied by urinary incontinence and gait disturbance.

A 40-year-old male, treated with radiotherapy and supraophthalmic intracarotid artery (ICA) ACNU infusion for glioblastoma in the right occipital lobe, developed cerebral infarction secondary to vasculopathy manifesting as hemiparesis 3 months after a second ICA injection. The initial diagnosis was focal neurotoxicity, but angiography revealed severe vasospasm of the anterior choroidal artery. The symptoms improved gradually with therapy for the vasospasm. Angiography is required to discriminate vasospasm and focal neurotoxicity as a complication of ICA injection of antineoplastic agents.

We report on the toxicity, intrathecal pharmacokinetics, and therapeutic effect of the ventriculolumbar perfusion of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitros our ea hydrochloride (ACNU) against the subarachnoid dissemination of primary central nervous system tumors. Fifteen patients received ventriculolumbar perfusion of ACNU. One was treated with ventriculolumbar perfusion of ACNU alone, and the others underwent concomitant systemic chemotherapy; three of these patients received irradiation as well. ACNU was administered at an initial dose of 0.5 and was increased to 1.5 to 10.0 mg in six patients. Because of a lack of Level 2 or greater toxicity, the subsequent seven patients received 8.7 to 10.0 mg of ACNU dissolved in artificial cerebrospinal fluid (CSF) at a concentration of 0.1 mg/ml, from the start of the treatment. During ACNU administration, the lumbar CSF was drained at approximately the same rate as that of the infusion. Twelve patients received from 3 to 42 courses (average, 14 courses). The cumulative dose of ACNU ranged from 5 to 330.4 mg (average, 82.9 mg). One patient had a convulsion; two patients experienced transient headache, nausea, and vomiting; two others reported transient headache, nausea, vomiting, and fecal incontinence; and one experienced transient nausea, vomiting, and fecal incontinence. No side effects were noted in the other nine patients. When 9.0 to 9.5 mg of ACNU, dissolved in 90 to 95 ml of artificial CSF, was administered for 37 to 52 min, the maximum concentration of ACNU in the lumbar CSF was 9.86 to 12.79 micrograms/ml and the area under the drug concentration-time curve was 260.8 to 502.5 micrograms.min/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors report five patients with primary intracerebral non-Hodgkin's lymphoma who were treated with several cycles of intra-arterial injection of 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) at doses of 80 to 100 mg/m2/injection at several monthly intervals. There was no simultaneous use of steroids, and no patients had concomitant immunosuppression; no patient was human immunodeficiency virus positive. This therapy was initially used in four patients with advanced recurrent lymphoma. These patients experienced tumor progression despite our institutional standard therapy comprising cranial irradiation followed by repeated courses of systemic multi-agent chemotherapy (cyclophosphamide, vincristine, adriamycin, and prednisolone) more than 3 months previously. Based upon brain computed tomography scans and clinical neurologic examinations, three of the four cases showed partial responses ranging from 10 to 12 months in duration, whereas the other patient remained stable without worsening for 8 months. A fifth case was particularly noteworthy; this patient had no prior therapy and intra-arterial chemotherapy alone induced an 18-month, disease-free remission. No significant therapy-related complications nor neurotoxicity were seen. These results suggest that intra-arterial administration of ACNU may be a potential candidate for intracerebral lymphoma therapy.

Background: The clinical dose of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitro- sourea hydrochloride (ACNU) is limited by the bone marrow suppression it produces. The authors investigated whether bone marrow transplantation (BMT) associated with a high dose of ACNU could alleviate marrow toxicity and achieve greater antitumor effects in Fischer rats., Methods and Results: High doses of ACNU (20, 25, and 30 mg/kg) were administered on day 1, followed by injection of syngeneic bone marrow cells on day 3. Patterns of leukocyte recovery were compared in BMT and non-BMT groups. There was a significant benefit in leukocyte recovery in the BMT groups. A 9L glioma that was sensitive to ACNU was transplanted into the brain tissue of rats. Seven days later, the animals were divided into three groups based on the dose of ACNU (2, 10, and 25 mg/kg). The median survival time increased with larger ACNU doses., Conclusions: This suggested that high-dose ACNU chemotherapy with BMT could achieve greater antitumor effects and less bone marrow suppression than high-dose ACNU alone.

ACNU [1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride], one of the chloroethylnitrosoureas (CENUs), is believed to be effective against malignant glioma when intravenously or intrathecally administered. A rat model with meningeal gliomatosis (MG) induced by an intracisternal inoculation of rat C6 or 9L glioma cells was intrathecally and intravenously treated with ACNU in order to test the feasibility of intrathecal chemotherapy with ACNU in the treatment of meningeal gliomatosis. The median survival time (MST) of the animals was significantly prolonged when ACNU was intrathecally administered at dosages of 0.5 to 1.5 mg kg-1 in the early stages of MG, i.e. within 3 days after the tumour inoculation, whereas intravenous therapy with ACNU at a dose of 15 mg kg-1 did not exhibit any efficacy in the rats inoculated with C6 glioma cells (C6-MG). Intrathecal ACNU, however, at dosages of up to 1.5 mg kg-1 failed to demonstrate any therapeutic effect in the late stage of MG, i.e. 5 days after the tumour inoculation, except in the rats inoculated with 9L brain tumour cells (9L-MG). Intravenous chemotherapy with ACNU at a dose of 15 mg kg-1 extended the MST of the 9L-MG rats more significantly in the late stage of MG than in its early stage. This points to the feasibility of intrathecal ACNU in the treatment of meningeal gliomatosis in its early stages, but not in its late stages in which intravenous ACNU might be more effective than intrathecal treatment against MG of which the parenchyma has already been deeply invaded by the tumour.

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 effect of recombinant human interleukin 1 beta (rHuIL-1 beta) on myelosuppression induced by 3-[(4-amino-2-methyl-5-pyrimidynyl)methyl]-1-(2-chloroethyl)-1-nit rosourea hydrochloride (ACNU) was studied. In in vivo study using BALB/c mice, pretreatment with 1 microgram/mouse of rHuIL-1 beta as a single intraperitoneal (i.p.) injection had a significant preventive effect on thrombocytopenia as well as granulocytopenia induced by ACNU at an intravenous dose of 60 mg/kg. Facilitated recovery by rHuIL-1 beta administered seven days after injection of high-dose ACNU was also observed. Experimental combination immunochemotherapy with high-dose ACNU and rHuIL-1 beta was performed in nude mice inoculated with human glioblastoma subcutaneously. The elongation of the survival time of the tumor bearing nude mice was also observed in combined use of high dose ACNU with rHuIL-1 beta. Seven patients with malignant brain tumors received intravenous 2.5-3 mg/kg ACNU. All patients were subcutaneously injected with 2 x 10(4)-U or more rHuIL-1 beta twice a week or daily. The mean nadir of leukocyte, granulocyte, and thrombocyte counts of the 7 patients received 2.5-3 mg/kg ACNU were significantly higher than in matched historical controls. In combination with rHuIL-1 beta, it may be possible to use chemotherapeutic agents at a relatively high dose.

Forty patients with malignant supratentorial gliomas received iterative intraarterial (IA) infusions of ACNU, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea at a dose of 150 mg repeated every 6 weeks. Group A consisted of eighteen patients previously treated with surgery, radiation therapy (RT) and sometimes chemotherapy, who received IA ACNU at tumor recurrence. Group B consisted of twenty two patients who received IA ACNU in the postoperative pre-RT period. In group A, 8/18 patients (44%) had an objective response, including 6/12 anaplastic astrocytomas (AA) and 2/6 glioblastoma multiforme (GBM), while 10/18 patients (56%) did not respond. Median survival time was 6 months for GBM and 12 months for AA. In group B, 6/22 patients (27%) had an objective response (4/18 GBM and 2/4 AA) and 16/22 patients (73%) did not respond. Nine patients had such an extensive tumor after one or two courses of IA ACNU that RT was cancelled. Median survival time was 8 months for GBM and 8 months for AA. Three patients (8%) had ophthalmologic toxicity on the infused side. There was no case of leukoencephalopathy.

A total of 24 patients presenting with small-cell lung cancer either resistant to or relapsing within 3 months after first-line treatment were entered in a phase II study of 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU). ACNU was given i.v. at a dose of 75 mg/m2 every 6 weeks. We observed a partial response of 7 months' duration in one patient and one case of stable disease that lasted for 6 months; all other subjects exhibited progressive disease. Two patients developed brain metastases during treatment. The toxicity of ACNU consisted mainly of bone marrow suppression, especially thrombocytopenia. At this dose and on this schedule, ACNU shows minimal activity as second-line treatment in small-cell lung cancer.

Thirty-two patients with metastatic colorectal cancer were entered in a phase II study of ACNU as first-line treatment. ACNU was given at a dose of 100 mg/m2 i.v. every six weeks. In 30 evaluable patients we observed partial responses lasting 5 and 8 months in 2 patients with liver metastases, and stable disease in 4 patients. The toxicity mainly consisted of leuco- and trombocytopenia. We conclude that in this dose and schedule ACNU has only very limited activity in metastatic colorectal cancer.

A 44-year-old female with malignant astrocytoma received subtotal removal and high dose (200 mg/m2) intra-arterial 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2- chloroethyl)-3-nitrosourea hydrochloride (ACNU) with autologous bone marrow transplantation. Tumor remission with minimal bone marrow suppression was achieved. However, she developed severe encephalopathy and computed tomographic scans revealed a low-density area at the ACNU delivery site. She received glycerol solution to treat the brain edema and recovered completely from the encephalopathy. Intra-arterial ACNU exceeding 200 mg/m2 possibly causes neurotoxicity.

A total of 62 patients with metastatic or locally advanced non-small-cell lung cancer were entered in a phase II study of ACNU. Initially, the drug was given i.v. at a dose of 100 mg/m2 every 6 weeks, but due to observed haematological side effects in chemotherapy-pretreated patients, the dose was lowered in this group to 75 mg/m2. We observed one complete response in a subject exhibiting multiple lung metastases and a partial response in two patients, one showing brain metastases and one who experienced local disease recurrence. The toxicity of ACNU mainly consisted of bone marrow suppression especially thrombocytopenia, with one toxic death occurring due to intracerebral haemorrhage. We concluded that at this dose and on this schedule, ACNU has limited activity in non-small-cell lung cancer.

The EORTC Soft Tissue and Bone Sarcoma Group has conducted a phase II trial in 33 eligible patients with metastatic soft tissue sarcoma with nimustine 100 mg/m2 every 6 weeks. In 31 evaluable patients there were 3 (10%) partial responses lasting 4.5, 6 and 7.5 months, and 5 cases of stable disease. 12 patients had progressive disease and 11 patients early progressive disease. Toxicity consisted mainly of leukopenia and thrombocytopenia and nausea and vomiting. It is concluded that nimustine has only minor activity in soft tissue sarcoma.

The clinical effects and problems of intra-arterial water-soluble antitumor nitrosourea (ACNU) therapy following osmotic blood-brain barrier modification are discussed. Twenty-one patients with malignant brain tumors were divided into two groups. Group 1 consisted of 16 patients treated by operation, irradiation, and two or more courses of intracarotid infusion of ACNU 100 mg/body (1.7-2.2 mg/kg) following 20% mannitol 200 ml (1.3-1.6 ml/sec) (7 grade 4 astrocytomas, 5 grade 3 astrocytomas, and 4 others). Group 2 consisted of five patients treated by operation, irradiation, and repeated intracarotid infusion of ACNU 100 mg/body alone (grade 4 astrocytoma). The 2-year survival rate in Group 1 was 79% (11 of 14 cases followed up for longer than 2 years) and the 3-year survival rate was 67%. Five of seven grade 4 astrocytoma patients (71%) in Group 1 survived for more than 1 year 6 months, whereas four of five grade 4 astrocytoma in Group 2 died within 1 year 6 months. The measurement of the ACNU concentration in tumor tissues and blood in 11 brain tumors, after intracarotid infusion of ACNU with blood-brain barrier disruption, showed peak values in the tumor tissues of 3.02-32.53 micrograms/gm (mean, 9.67 micrograms/gm), about three to five times as high as that in blood in most cases. This method used in Group 1 appears to be relatively safe without permanent neurological deficits and offers a potential therapeutic effect when used in combination with appropriate premedication in suitable patients.

The neurotoxicity of local administration of nitrosoureas in malignant gliomas was investigated clinicopathologically. Twenty patients were entered into this study: 13 were treated with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and 7 with methyl 6-[3-(2-chloroethyl-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU). On the average, a single dose of 20 mg of ACNU was administered 15 times, for a total dose of 295 mg in each case, while a single dose of 11 mg of MCNU was given 2 times, for a total dose of 24 mg. These nitrosoureas provoked greater toxicity when the administration dose was larger or the indwelling multiperforated Silastic basket was in direct continuity with the ventricle or the basal cistern. Usually ACNU was well tolerated, whereas MCNU induced marked brain edema. Side effects consisted of headache, nuchal stiffness, vomiting, motor weakness, and cranial nerve palsy for ACNU, and headache, vomiting, abnormal respiration, and arrhythmia for MCNU. Pathological changes were represented by capsule formation, spongy degeneration and reactive gliosis of adjacent white matter, occlusion of neighboring arteries, and demyelination of cranial nerves in the patients treated with ACNU, while they were represented by focal brain necrosis in two patients treated with MCNU. The differences in neurotoxity of ACNU and MCNU conceivably derive from the different blood-brain delivery of these drugs.