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At least 19 recordsLinked to original sources
PubMed1994

Cyclophosphamide, cisplatin, and carmustine: pharmacokinetics of carmustine following multiple alkylating-agent interactions.

Cyclophosphamide, cisplatin, and carmustine (CPA/cDDP/BCNU) constitute a combination alkylating-agent regimen commonly used with autologous marrow support. Its therapeutic effectiveness is accompanied by sporadic life-threatening and fatal toxicities, the most common of which is acute lung injury. We have previously shown that variation in the BCNU AUC can be correlated to the risk of pulmonary injury in patients receiving CPA/cDDP/BCNU. In an attempt to understand further the role of interpatient variation in drug pharmacokinetics (PK) with respect to pharmacodynamic outcomes, we evaluated the effect of pretreatment with CPA, cDDP, or both on BCNU PK in male Sprague-Dawley rats. The drug-administration pattern was designed to mimic that of the CPA/cDDP/BCNU regimen in patients. Each pretreatment increased both the absolute value of and the variation in BCNU AUC relative to the control values. These findings are consistent with an important rate-limiting elimination pathway for BCNU in rats and may explain the wide interpatient variability of BCNU AUC and the sporadic pulmonary toxicity seen in patients receiving CPA/cDDP/BCNU.

Animals↗
PubMed2004

Randomized comparison of stereotactic radiosurgery followed by conventional radiotherapy with carmustine to conventional radiotherapy with carmustine for patients with glioblastoma multiforme: report of Radiation Therapy Oncology Group 93-05 protocol.

PURPOSE: Conventional treatment of glioblastoma multiforme (GBM) cures less than 5% of patients. We investigated the effect of stereotactic radiosurgery (SRS) added to conventional external beam radiation therapy (EBRT) with carmustine (BCNU) on the survival of patients with GBM. METHODS AND MATERIALS: A total of 203 patients with supratentorial GBM (tumor < or =40 mm) were randomly assigned either to postoperative SRS followed by EBRT (60 Gy) plus BCNU (80 mg/m(2) Days 1-3 every 8 weeks for six cycles) or to EBRT with BCNU alone. The dose of radiosurgery was tumor size-dependent and ranged from 15 Gy for largest to 24 Gy for smallest tumors. RT and BCNU were identical in both arms. RESULTS: At a median follow-up time of 61 months, the median survival in the radiosurgery group was 13.5 months (95% confidence interval, 11.0-14.8) as compared with 13.6 months (95% confidence interval, 11.2-15.2, p = 0.5711) for the standard treatment group. There were also no significant differences in 2- and 3-year survival rates and in patterns of failure between the two arms. Quality of life deterioration and cognitive decline at the end of therapy, compared with baseline, were comparable and there was no difference in quality-adjusted survival between the arms. CONCLUSIONS: Stereotactic radiosurgery followed by EBRT and BCNU does not improve the outcome in patients with GBM nor does it change the general quality of life or cognitive functioning.

Adolescent↗
PubMed1993

Acute lung injury following treatment with high-dose cyclophosphamide, cisplatin, and carmustine: pharmacodynamic evaluation of carmustine.

BACKGROUND: Therapy with high-dose cyclophosphamide, cisplatin, and carmustine (BCNU) plus autologous bone marrow transplantation has been extensively studied as treatment for patients with stage II or III breast cancer who have a 70% or greater risk of developing metastatic disease. This therapy is being used in a cooperative intergroup phase III clinical trial. In the cyclophosphamide-cisplatin-BCNU regimen, cyclophosphamide and BCNU, but not cisplatin, have been reported to cause acute lung injury, suggesting that either cyclophosphamide or BCNU may contribute to this injury. PURPOSE: The purpose of this study was to analyze clinical and pharmacokinetic data from our ongoing phase II trials and to determine whether there is an association between BCNU pharmacokinetics and acute lung injury following cyclophosphamide-cisplatin-BCNU therapy. METHODS: We performed a retrospective study of 38 patients treated following induction therapy or relapse, 29 with stage II-IV breast cancer and nine with intermediate and high-grade stage III-IV non-Hodgkin's lymphoma. These patients received therapy with cyclophosphamide at a dose of 1875 mg/m2 daily as a 1-hour intravenous infusion for 3 days, cisplatin at 55 mg/m2 per day as a 72-hour continuous intravenous infusion, and BCNU at 600 mg/m2 as a 2-hour infusion immediately following completion of the cisplatin infusion. Data from analysis of blood samples were used to calculate pharmacokinetic parameters for BCNU, and acute lung injury was determined on the basis of pulmonary function test results and histologic examination of lung biopsy specimens. RESULTS: Our analysis showed that 20 (53%) of the 38 patients developed pulmonary injury following treatment. Twelve (60%) of the 20 had values for area under the curve (AUC) for BCNU concentration x time that exceeded 600 (micrograms/mL) x minute, whereas only two (11%) of the 18 without pulmonary injury had values above this level (P < .03). Thus, 12 (86%) of 14 patients with BCNU AUC greater than 600 (micrograms/mL) x minute developed lung injury. CONCLUSIONS: These results suggest that BCNU exposure greater than 600 (micrograms/mL) x minute is associated with increased risk of acute lung injury after cyclophosphamide-cisplatin-BCNU therapy and may be a major cause of pulmonary drug injury following this regimen. IMPLICATIONS: Strategies aimed at more uniform drug exposure or selective neutralization of chlorethylisocyanate, one of the two major hydrolysis products of BCNU, might reduce the incidence of acute lung injury following this regimen without major compromise of antitumor effect.

Acute Disease↗
PubMed2003

Phase III study comparing three cycles of infusional carmustine and cisplatin followed by radiation therapy with radiation therapy and concurrent carmustine in patients with newly diagnosed supratentorial glioblastoma multiforme: Eastern Cooperative Oncology Group Trial 2394.

PURPOSE: This phase III Eastern Cooperative Oncology Group-Southwest Oncology Group intergroup study was conducted to determine whether three 72-hour infusions of carmustine (BiCNU) and cisplatin administered monthly before external-beam radiotherapy would improve the survival of patients with newly diagnosed glioblastoma multiforme. The control arm consisted of radiation with standard adjuvant BiCNU. PATIENTS AND METHODS: A total of 223 patients were accrued from 1996 to 1999. Of these, 219 patients were eligible; 109 were randomly assigned to the experimental arm, and 110 were randomly assigned to the control arm. Randomization was stratified by age, performance status, and extent of resection. RESULTS: The median age of the patients was 55 years; 55% were male, 93% were white, 26% had a biopsy only, and 84% were ambulatory. Treatment arms were well balanced with respect to baseline characteristics. Median follow-up time of the 15 patients still alive at the time of analysis was 3.3 years (range, 2 to 5 years). Median survival times for the standard and experimental arms were 11.2 and 11.0 months (P =.33, two-sided log-rank test), and survival at 1 year was 45% versus 44%, respectively. Fifty-six percent of patients received all three cycles of BiCNU/cisplatin, 12% received two cycles, and 31% received only one cycle. Toxicity was primarily hematologic and was more common in the experimental arm (P <.01). CONCLUSION: This study demonstrates that 72-hour infusions of BiCNU and cisplatin followed by radiation do not improve median survival, survival at 1 year, or time to progression. Furthermore, this treatment requires more time in the hospital and is associated with more serious toxicities than standard therapy.

Adult↗
PubMed2006

Phase III trial of carmustine and cisplatin compared with carmustine alone and standard radiation therapy or accelerated radiation therapy in patients with glioblastoma multiforme: North Central Cancer Treatment Group 93-72-52 and Southwest Oncology Group 9503 Trials.

PURPOSE: In patients with newly diagnosed glioblastoma multiforme, to determine whether cisplatin plus carmustine (BCNU) administered before and concurrently with radiation therapy (RT) improves survival compared with BCNU and RT and whether survival using accelerated RT (ART) is equivalent to survival using standard RT (SRT). PATIENTS AND METHODS: After surgery, patients were stratified by age, performance score, extent of surgical resection, and histology (glioblastoma v gliosarcoma) and then randomly assigned to arm A (BCNU plus SRT), arm B (BCNU plus ART), arm C (cisplatin plus BCNU plus SRT), or arm D (cisplatin plus BCNU plus ART). RESULTS: Four hundred fifty-one patients were randomly assigned, and 401 were eligible. Frequent toxicities included myelosuppression, vomiting, sensory neuropathy, and ototoxicity and were worse with cisplatin. There was no difference in toxicity between SRT and ART. Median survival times and 2-year survival rates for patients who received BCNU plus RT (arms A and B) compared with cisplatin, BCNU, and RT (arms C and D) were 10.1 v 11.5 months, respectively, and 11.5% v 13.7%, respectively (P = .19). Median survival times and 2-year survival rates for patients who received SRT (arms A and C) compared with ART (arms B and D) were 11.2 v 10.5 months, respectively, and 13.8% v 11.4%, respectively (P = .33). CONCLUSION: Cisplatin administered concurrently with BCNU and RT resulted in more toxicity but provided no significant improvement in survival. SRT and ART produced similar toxicity and survival.

Adult↗
PubMed2002

The Brain Tumor Cooperative Group NIH Trial 87-01: a randomized comparison of surgery, external radiotherapy, and carmustine versus surgery, interstitial radiotherapy boost, external radiation therapy, and carmustine.

OBJECTIVE: The objective of the Brain Tumor Cooperative Group NIH Trial 87-01 trial was to investigate the effect of additional implanted radiation therapy in newly diagnosed patients with pathologically confirmed malignant gliomas. METHODS: The study involved a randomized comparison of surgery, external beam radiotherapy, and carmustine (BCNU) versus surgery, external beam therapy, interstitial radiotherapy boost, and BCNU in newly diagnosed malignant gliomas. (125)I was chosen as best suited for this effort because it allowed preimplantation planning and postimplantation quality assurance review. Two hundred ninety-nine patients met the eligibility criteria and were randomized into the two arms of the study between December 1987 and April 1994. Follow-up continued for an additional 3 years. Twenty-nine patients were identified as having committed protocol violations and were excluded, resulting in 270 subjects in the Valid Study Group. One hundred thirty-seven patients received external beam radiation and BCNU, and 133 underwent the (125)I implantation plus external beam radiation and BCNU therapy. RESULTS: The overall median survival for the Valid Study Group was 64.3 weeks. The median survival for patients receiving additional therapy of (125)I was 68.1 weeks, and median survival for those receiving only external beam radiation and BCNU was 58.8 weeks. The cumulative proportion surviving between the two treatment groups was not statistically significantly different (log-rank test, P = 0.101). As in other studies in the literature, age, Karnofsky score, and pathology were predictors of mortality. Additional analyses incorporating an adjustment for these prognostic variables, either in a stratified analysis or Cox proportional hazards model, did not result in statistically significant differences in the cumulative proportion of patients surviving between the two treatment groups. CONCLUSION: We conclude that there is no long-term survival advantage of increased radiation dose with (125)I seeds in newly diagnosed glioma patients.

Antineoplastic Agents, Alkylating↗
PubMed1986

Phase III study of 5-FU and carmustine versus 5-FU, carmustine, and doxorubicin in advanced gastric cancer.

Seventy-seven patients with advanced gastric carcinoma were prospectively randomized to receive 5-FU and carmustine (FB) with or without doxorubicin (FAB). Thirty-five patients were evaluable for response. Neither the response rates (partial remission, 11% for FB and 24% for FAB) nor survival times (median, 4.0 months for FB and 5.5 months for FAB) were statistically different. The median survival of patients with partial remission (7.8 months) and those with no change (7.4 months) was significantly prolonged compared to patients with progressive disease (4.5 months). The side effects of both regimens after the first treatment cycle (except alopecia in FAB) were low. After the second cycle more pronounced myelosuppression in the FAB arm was observed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Lack of survival benefit after stereotactic radiosurgery boost for glioblastoma multiforme: randomized comparison of stereotactic radiosurgery followed by conventional radiotherapy with carmustine to conventional radiotherapy with carmustine for patients with glioblastoma multiforme: report of radiation therapy oncology group 93-05 protocol: in regard to Souhami et al. (Int J Radiat Oncol Biol Phys 2004;60:853-860).

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Antineoplastic Agents, Alkylating↗
PubMed2004

Effects on Walker 256 tumour of carmustine associated with a cholesterol-rich microemulsion (LDE).

A cholesterol-rich microemulsion that binds to low-density lipoprotein (LDL) receptors (LDE), after injection into the bloodstream, concentrates in neoplastic tissues that over-express those receptors. LDE can thus serve as a vehicle for drug targeting. It was shown that carmustine side effects are pronouncedly reduced when the drug is associated with LDE in cancer patients. In this study, the therapeutic action of LDE associated with carmustine was compared with that of the non-associated drug in rats implanted with Walker 256 tumour. The toxicity and anti-tumour activity in rats treated with either free carmustine or carmustine associated with LDE and in control rats treated with saline solution were determined after a single intraperitoneal injection. The LD90 (90% lethal dose) of LDE-carmustine was 77 mg kg(-1) and of free carmustine was 44 mg kg(-1), indicating that LDE decreases toxicity. LDE-carmustine was able to decrease tumour mass at a lower dose level than free carmustine. Tumour regression time was shorter in LDE-carmustine- than in free carmustine-treated animals. Therefore, this study shows that the association of carmustine with LDE increases the therapeutic index of carmustine.

Animals↗
PubMed2001

Quinacrine enhances carmustine therapy of experimental rat glioma.

OBJECTIVE: The high rate of mutagenesis in malignant cells has been considered to be a primary factor in the appearance of chemotherapy-resistant cell clones in glioblastomas. Quinacrine binds strongly to deoxyribonucleic acid, preventing mutagenesis. We investigated whether quinacrine could improve carmustine therapy in C6 cell cultures and in C6 malignant gliomas implanted subcutaneously into Wistar rats. METHODS: A potential chemopreventive effect of quinacrine on acquired resistance to carmustine therapy was studied in vitro and in vivo. Deoxyribonucleic acid damage was measured in cultured C6 cells by using the micronucleus test. Wistar rats with subcutaneously implanted C6 gliomas were treated with carmustine, quinacrine, or carmustine plus quinacrine, using pharmacological schemes similar to those used for human patients. RESULTS: The addition of quinacrine to cultured C6 cells did not modify carmustine-induced cytotoxicity; however, the deoxyribonucleic acid damage in surviving cells was minor, as indicated by the frequency of micronucleated cells. The surviving cells continued to be susceptible to a second exposure to carmustine, in contrast to non-quinacrine-treated control cells, which developed resistance to carmustine in a subsequent exposure (P < 0.05). The rate of tumor remission was higher for glioma-bearing rats treated with quinacrine plus carmustine, compared with rats treated with carmustine alone (P < 0.01). CONCLUSION: The addition of quinacrine to carmustine therapy increases the antineoplastic effect of the carmustine therapy. Our results suggest that chemical inhibition of mutagenesis in malignant glial cells during chemotherapy prevents the appearance of resistant clones.

Animals↗
PubMed2006

Cotreatment with a novel phosphoinositide analogue inhibitor and carmustine enhances chemotherapeutic efficacy by attenuating AKT activity in gliomas.

BACKGROUND: Heightened activity of the AKT signaling pathway is prominent in malignant gliomas and has been suggested to play a role in treatment resistance. Selective targeting of AKT, therefore, may increase chemosensitivity. Recently, a novel class of AKT-selective inhibitors has been described, including SH-6, a phosphatidylinositol analogue. METHODS: The effects of SH-6 on AKT signaling were tested in glioma cells, and the putative role of AKT signaling in chemoresistance was tested by attenuating AKT signaling pharmacologically and genetically. The initial characterization of SH-6 included treatment of glioma cells with increasing doses of SH-6 (0.30-30 microM) and examining the effects on AKT signaling proteins by Western blot analyses and in kinase assays with immunoprecipitated AKT1. Dose-response studies with SH-6 administered to glioma cell lines were performed using a luminescent cell-viability assay (0.1-30 microM). Studies examining the effect of carmustine, either alone or in combination with either the phosphatidylinositol 3-kinase inhibitor LY294002 or SH-6, were performed by cell viability assays and clonogenic survival assays. The effect of carmustine on AKT activity as a response to treatment also was examined. Caspase assays were used to examine the potential role of apoptosis in SH-6/ carmustine -elicited cell death. Finally, the induction of a dominant-negative AKT1 transgene was used in combination with carmustine to demonstrate the role of AKT1 in carmustine chemoresistance. RESULTS: Serum-stimulated phosphorylation of AKT1 was inhibited by SH-6 at doses > or =10 microM (>70% decrease in Threonine 308 and Serine 473 phosphorylation of AKT1). In adenosine triphosphate assays, 72 hours of treatment with SH-6 led to 50% lethal doses near 10 microM for 2 cell lines tested. SH-6 enhancement of carmustine-mediated cell death led to synergistic increases in Caspase 3/Capsase 7 activity, implicating apoptosis as the cell death mechanism. In clonogenic assays, SH-6 cotreatment with carmustine significantly decreased the number of colonies at 10 microM (P < .05) compared with carmustine alone. No decrease was observed in cells that were treated with SH-6 alone (10 microM). LY294002 (10 microM) was also able to enhance the effects of carmustine significantly in both cell lines. CONCLUSIONS: In the current study, the authors characterized the efficacy of a new class of adjuvant chemotherapeutics that show promise in enhancing the efficacy of standard chemotherapy regimens in gliomas.

Antineoplastic Agents, Alkylating↗
PubMed2000

Phase I clinical and pharmacological study of O6-benzylguanine followed by carmustine in patients with advanced cancer.

O6-benzylguanine (BG) is a potent inactivator of the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) that enhances sensitivity to nitrosoureas in tumor cell lines and tumor-bearing animals. The major objectives of this study were to define the optimal modulatory dose and associated toxicities of benzylguanine administered alone and in combination with carmustine; to define the maximally tolerated dose and associated toxicities of carmustine administered with benzylguanine and to describe the pharmacokinetics of BG in humans and its effects on AGT depletion and recovery in peripheral blood mononuclear cells. Patients with histologically confirmed advanced solid tumors or lymphoma that had failed to respond to standard therapy or for which no standard therapy was available were eligible to participate in this study. Patients initially received BG as a 1-h i.v. infusion without carmustine. After a 14-day washout (ie., without therapy) period, patients received BG as a 1-h i.v. infusion followed, 1 h later, by a 15-min i.v. infusion of carmustine. Cycles of chemotherapy were repeated every 6 weeks. Cohorts of patients received BG doses ranging from 10 to 120 mg/m2 and carmustine doses ranging from 13 to 50 mg/m2. Plasma and urine samples were collected and analyzed for BG, and O6-benzyl-8-oxoguanine concentrations and AGT activity was determined in peripheral blood mononuclear cells. There was no toxicity attributable to BG alone at any dose tested. Bone marrow suppression was the primary and dose-limiting toxicity of BG combined with carmustine and was cumulative in some patients. The neutrophil nadir occurred at a median of day 27, with complete recovery in most patients by day 43. Nonhematological toxicity included fatigue, anorexia, increased bilirubin, and transaminase elevation. Recommended doses for Phase II testing are 120 mg/m2 BG given with carmustine at 40 mg/m2. BG rapidly disappeared from plasma and was converted to a major metabolite, O6-benzyl-8-oxoguanine, which has a 2.4-fold higher maximal concentration and 20-fold higher area under the concentration versus time curve than BG. AGT activity in peripheral blood mononuclear cells was rapidly and completely suppressed at all of the BG doses. The rate of AGT regeneration was more rapid for patients treated with the lowest dose of BG but was similar for BG doses ranging from 20-120 mg/m2. In conclusion, coadministration of BG and carmustine is feasible in cancer patients, but the maximal dose of carmustine that can be safely administered with BG is approximately one-third of the standard clinical dose. Bone marrow suppression, which may be cumulative, is the dose-limiting toxicity of the combination. Prolonged AGT suppression is likely attributable primarily to the effect of O6-benzyl-8-oxoguanine.

Adult↗
PubMed2002

Association of carmustine with a lipid emulsion: in vitro, in vivo and preliminary studies in cancer patients.

PURPOSE: We had previously shown in acute leukemia and in breast and ovary carcinoma patients that a cholesterol-rich emulsion (LDE) that binds to receptors for low-density lipoprotein (LDL) may concentrate in neoplastic tissues. In this study, the potential of LDE as a carrier for anticancer drugs was investigated. METHODS: LDE was associated with carmustine, and the cytotoxicity of the LDE-carmustine complex was studied in a neoplastic cell line and its biodistribution was studied in mice. The plasma kinetics of the complex and its uptake by tumor and normal tissue were determined in cancer patients. Finally, an exploratory clinical study to determine the toxicity profile of LDE-carmustine at escalating dose levels was conducted in 42 advanced cancer patients refractory to conventional chemotherapy. RESULTS: Carmustine formed a stable association with LDE. The pharmacological action of carmustine, as tested in cancer cells, was not diminished by association with LDE compared with the free drug and was indeed mediated by the LDL receptor. The biodistribution in mice and plasma kinetics in patients of the emulsion were not changed by association of the drug. The uptake of LDE-carmustine by tumor was severalfold greater than the uptake by the corresponding normal tissue. Finally, patients treated with LDE-carmustine showed negligible side effects even at very high dose levels. CONCLUSIONS: Association with LDE preserves the cytotoxicity of carmustine and markedly diminishes its side effects.

Adult↗
PubMed1998

Intralesionally implanted cisplatin plus systemic carmustine for the treatment of brain tumor in rats.

BACKGROUND AND OBJECTIVES: The benefit of conventional chemotherapy for the treatment of malignant brain tumors, although limited, is real. A major obstacle in the treatment of these lesions is the ability to deliver drug across the blood-brain barrier (BBB). Local drug implantation, circumventing the BBB, has been a useful strategy for treatment of intracranial lesions, and may work synergistically with systemic chemotherapy. To test this hypothesis, either intraperitoneal (i.p.) carmustine or cisplatin was combined with the intracranial (i.c.) administration of polymer-delivered cisplatin in rats with intracranial tumors. METHODS AND RESULTS: 9L gliosarcoma tumor cells (5 x 10(3)) were administered through a right frontal lobe cannula in rats 7 days prior to treatments. Cisplatin-loaded biodegradable polymer was then administered via the cannula, with free cisplatin or carmustine injected i.p. Animals were monitored for 60 days post-treatment. In experiment 1, i.c. cisplatin at a dose of 0.5, 1.0, 2.0, and 4.0 mg/m2 resulted in a mean survival time of 34 +/- 3, 39 +/- 14, 47 +/- 11, and 31 +/- 20 days (MST +/- SD), respectively, compared to 26 +/- 4 days in the control group and 30 +/- 7 days in the group treated with 50 mg/m2 i.p. free cisplatin. In experiment 2, i.p. free cisplatin at 25, 40, 50, and 100 mg/m2 resulted in a MST of 28 +/- 3, 30 +/- 4, 32 +/- 3, and 14 +/- 8 days, respectively, compared to 26 +/- 1 days in the control group. In experiment 3, the MST in the groups treated with 0.5 mg/m2 of i.c. cisplatin, 25 mg/m2 of i.p. cisplatin, 10 mg/kg of i.p. carmustine, i.c. cisplatin (0.5 mg/m2) plus i.p. cisplatin (25 mg/m2), and i.c. cisplatin (0.5 mg/m2) plus i.p. carmustine (10 mg/kg) was 30 +/- 4 days (P > 0.05), 28 +/- 2 (P > 0.05), 36 +/- 4 (P < 0.01), 32 +/- 3 (P < 0.01), and 50 +/- 11 days (P < 0.01), respectively, compared to the tumor control group (26 +/- 1 days). Long-term survivors (29%) were seen only in the i.c. cisplatin plus i.p. carmustine group. Additive toxicity was not observed. CONCLUSIONS: Intralesional polymer-delivered (i.c.) cisplatin plus systemic (i.p.) carmustine is highly effective for the treatment of intracranial 9L gliosarcoma in tumors.

Animals↗
PubMed1995

Sensitization of human colon tumour cell lines to carmustine by depletion of O6-alkylguanine-DNA alkyltransferase.

In nine human colon tumour cell lines the relationship between O6-alkylguanine-DNA alkyltransferase (O6-AGT) activity and carmustine resistance was investigated. Three lines with O6-AGT activity below 25 fmol/mg protein had carmustine ED50 values ranging from 5.0 microM to 11.9 microM; six lines displaying an O6-AGT activity above 240 fmol/mg protein had ED50 values ranging from 28.9 microM to 69.5 microM. In lines with low O6-AGT activity, depletion of the repair protein by O6-benzylguanine resulted in a marginal increase of carmustine cytotoxicity (sensitization factors less than 2). In the majority of cell lines with high O6-AGT activity, pretreatment with O6-benzylguanine resulted in a pronounced sensitization to carmustine. In one line, an optimal time schedule for sensitization of colon tumour cells by O6-benzylguanine was assessed; continuous exposure to O6-benzylguanine > or = 16 h after carmustine exposure) was superior to short-term exposure limited to a period before carmustine treatment.

Carmustine↗
PubMed2004

The glutathione reductase inhibitor carmustine induces an influx of Ca2+ in PC12 cells.

We studied the effects of carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea) on the intracellular Ca(2+) concentration ([Ca(2+)](i)) in PC12 cells using fura-2 fluorescence imaging. Carmustine (100 microM) caused a delayed increase in [Ca(2+)](i) that developed within approximately 3 h. This effect was enhanced in cells that were pretreated with an inhibitor of glutathione (GSH) synthesis, buthionine sulfoximine (BSO, 200 microM, 24 h), and was suppressed in cells that were treated with an antioxidant deferoxamine (50 microM). The carmustine-induced increase in [Ca(2+)](i) was absolutely dependent on the presence of extracellular Ca(2+) and could be inhibited by dihydropyridine blockers of L-type voltage-gated Ca(2+) channels (nimodipine or nitrendipine, 10 microM). The increase in [Ca(2+)](i) was also suppressed in Cl(-)-free solution and in the presence of the Cl(-) channel blockers, indanyloxyacetic acid 94 (IAA-94, 100 microM) and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, 100 microM). The inhibition was complete when the blockers were applied simultaneously with carmustine and was partial when the blockers were applied after the initial increase in [Ca(2+)](i). We conclude that carmustine induces an influx of extracellular Ca(2+) through L-type Ca(2+) channels and that this effect is mediated by oxidative stress that results from the depletion of GSH following the inhibition by carmustine of glutathione reductase.

Animals↗
PubMed2004

Phase I study pilot arms of radiotherapy and carmustine with temozolomide for anaplastic astrocytoma (Radiation Therapy Oncology Group 9813): implications for studies testing initial treatment of brain tumors.

PURPOSE: To determine the safety and toxicity of carmustine (BCNU) and temozolomide (TMZ) with radiotherapy (RT) in newly diagnosed anaplastic astrocytoma. METHODS AND MATERIALS: Patients >18 years old with anaplastic astrocytoma, a Karnofsky performance status score of > or =60, and adequate pulmonary function were eligible. All patients provided informed consent. Standard RT started within 5 weeks of diagnosis. In both arms, 150 mg/m(2) of TMZ was given on Days 1-5 of RT. In Arm 1, 200 mg/m(2) of carmustine was given on Day 1 of RT. In Arm 2, 150 mg/m(2) of carmustine was given on Day 5 of RT. After RT, TMZ and carmustine were repeated for a total of six cycles. RESULTS: A total of 15 and 14 patients were enrolled in the two pilot arms. Because of hematologic and pulmonary toxicities, dose reductions by the second cycle of therapy occurred in >70% of the patients in Arm 1 and >50% in Arm 2 despite a reduction in the carmustine dose. CONCLUSION: The results of these pilot studies have implications for the design of studies testing the initial treatment of brain tumors. Because of the poor tolerance of the combination, the multicooperative group Phase III study consists of two randomized arms of single-agent carmustine vs. single-agent TMZ.

Antineoplastic Combined Chemotherapy Protocols↗