Search

Adherence to analgesics in cancer patients has scarcely been studied. In this study, the Medication Event Monitoring System (MEMS) and medication diaries were compared with respect to feasibility and adherence measurements. Forty-six outpatients with nociceptive pain caused by cancer were asked to use MEMS for their analgesics and to record their medication usage in a diary for four weeks. Seventy-nine percent of the patients used MEMS for the full four-week period; 70% did so for the diary. The majority of patients were satisfied with both MEMS and diary. Adherence data assessed by MEMS and diary were comparable. Patients used the amount of analgesics adequately (taking adherence: 87%) but took them irregularly (timing adherence: 53%). Subgroup analyses in patients using single and multiple analgesic regimens confirmed the comparable suitability of both methods. MEMS and a medication diary are equally useful for analgesic adherence measurement in cancer patients with pain.

The effectiveness of platinum drugs in the treatment of cancer is hindered by intrinsic and acquired resistance. The cause of clinical resistance to platinum compounds is still unknown. In an attempt to identify new cellular mechanisms of cisplatin resistance, a one-step cisplatin-selection procedure was used to generate resistant sublines of the platinum sensitive A2780 ovarian cancer cell line. In the present study we selected an A2780 subline, A2780-Pt, that has a significantly reduced ability to accumulate cisplatin (36% of the parent A2780 cell line) and consequently shows a clear cisplatin-resistant phenotype (resistance factor, i.e., RF: 8.6). The A2780-Pt cell line was specifically cross-resistant to carboplatin (RF: 12.0), tetraplatin (RF: 8.1) and oxaliplatin (RF: 6.1) which was associated with a reduced cellular platinum accumulation (50%, 54% and 58% of A2780, respectively). No cross-resistance was found for a variety of other anticancer agents. Further experiments to determine the cause of the platinum resistance of the A2780-Pt cell line revealed that: (1) impaired cellular platinum accumulation could not be attributed to aberrant expression of MRP2 (ABCC2), CTR1 (SLC31A1), ATP7A or ATP7B, (2) resistance was not associated with platinum inactivation by metallothionein and glutathione, (3) the platinum efflux rate was similar to that of A2780, (4) the defect in cellular accumulation and the resistance could be overcome by treatment with cisplatin nanocapsules, consistent with impaired influx, and (5) the defect in accumulation is specific for platinum compounds in the cis-configuration, since A2780-Pt cells did not show reduced accumulation of transplatin. This specificity suggests that not passive diffusion but an inward transporter is impaired in A2780-Pt. In conclusion, we generated an A2780 subline that showed a uniquely stable platinum resistance phenotype, which could theoretically be caused by an impaired inward transporter specific for cis-configurated platinum compounds.

Purpose: To describe the documented growth, clinical course, and histopathology of retinoblastomas in an untreated and otherwise normal right eye of a 27-year-old white male with a g.153211T>A (p.Tyr606X) mutation in the retinoblastoma 1 gene, whose left eye was enucleated at age 2 years for 2 retinoblastomas. Design and Participants: Retrospective interventional case report. Interventions: Over the years, the right eye was irradiated twice and underwent trans-pars plana vitrectomy, transscleral cryocoagulation, argon laser photocoagulation of tumors and their feeder vessels, extracapsular cataract extraction with posterior chamber lens implantation, and neodymium:yttrium-aluminum-garnet laser treatment of after-cataract in the form of Elschnig's pearls. Finally, the patient received combination chemotherapy with etoposide, methotrexate, actinomycin D, cisplatin, and vincristine. Results: The eye finally had to be removed 12 years later due to tumor recurrences and seeding, pseudohypopyon, and elevated intraocular pressure. Histopathology showed microcellular retinoblastoma cells in the anterior chamber angle and trabecular meshwork without subconjunctival extension and in the nasal ciliary body, pars plana, internal limiting membrane, and optic nerve head anterior to the cribriform plate. The patient is without local or systemic recurrences at age 50, 11 years after the last eye was enucleated. Conclusions: This report shows that retinoblastoma patients may have tumor growth in their fellow eye 25 years after the first eye and also that Elschnig's after-cataract pearls still can arise after irradiation of a lens with 45 Gy.

Following a previous EORTC GU-Group study, in which linomide showed some activity in poor prognosis patients, this study was initiated to determine the effect of linomide in more favourable patients. 35 patients with metastatic renal cell carcinoma with good prognostic factors, i.e. good performance status, prior nephrectomy, no prior systemic therapy, and no liver, bone or brain metastases, were treated with linomide, a quinoline derivative with immunomodulating properties, at a dose of 10 mg daily, after an initial dose escalation during the first 4 weeks of treatment. In 29 evaluable patients, no responses were observed (95% confidence interval 0-10%). Best overall response was no change in 9 patients, for a median duration of 4 months. Linomide in this schedule was poorly tolerated, with 17% (6 patients) of patients being withdrawn and 23% (8 patients) having dose reductions due to adverse events, mostly influenza-like symptoms of myalgia, arthralgia and fatigue. Several cases of pericarditis and neuropathy were observed. In spite of selection of favourable prognosis patients and an optimal daily dosing schedule, linomide was not an effective treatment in renal cell carcinoma. In view of toxicity and lack of efficacy, there is no rationale in further testing the drug in this disease. (C) 1997 Published by Elsevier Science Ltd.

The aim of this study is to discover a gene set that can predict resistance to platinum-based chemotherapy in ovarian cancer. The study was performed on 96 primary ovarian adenocarcinoma specimens from 2 hospitals all treated with platinum-based chemotherapy. In our search for genes, 24 specimens of the discovery set (5 nonresponders and 19 responders) were profiled in duplicate with 18K cDNA microarrays. Confirmation was done using quantitative RT-PCR on 72 independent specimens (9 nonresponders and 63 responders). Sixty-nine genes were differentially expressed between the nonresponders (n=5) and the responders (n=19) in the discovery phase. An algorithm was constructed to identify predictive genes in this discovery set. This resulted in 9 genes (FN1, TOP2A, LBR, ASS, COL3A1, STK6, SGPP1, ITGAE, PCNA), which were confirmed with qRT-PCR. This gene set predicted platinum resistance in an independent validation set of 72 tumours with a sensitivity of 89% (95% CI: 0.68-1.09) and a specificity of 59% (95% CI: 0.47-0.71)(OR=0.09, p=0.026). Multivariable analysis including patient and tumour characteristics demonstrated that this set of 9 genes is independent for the prediction of resistance (p0.01). The findings of this study are the discovery of a gene signature that classifies the tumours, according to their response, and a 9-gene set that determines resistance in an independent validation set that outperforms patient and tumour characteristics. A larger independent multicentre study should further confirm whether this 9-gene set can identify the patients who will not respond to platinum-based chemotherapy and could benefit from other therapies.

The aim of this study was to evaluate the effect of pegylated interferon-alpha (PEG-IFN-alpha) on the plasma citrulline/arginine ratio, regarded as an index of nitric oxide (NO) synthesis, in patients with high-risk melanoma. Forty patients were randomly assigned to either PEG-IFN-alpha treatment (n = 22) or to observation only (control group, n = 18). The treatment group received 6 microg PEG-IFN-alpha/kg once a week during 8 weeks, followed by a maintenance dose of 3 microg/kg/wk. Blood was collected at different time points, plasma concentrations of citrulline and arginine were measured and the ratio of citrulline/arginine was calculated. Patients treated with PEG-IFN-alpha showed a significant decrease in the concentrations of citrulline and in the citrulline/arginine ratio during the whole study period, both compared to baseline values and to the control group. The data suggest that therapy with PEG-IFN-alpha results in a marked decrease in the synthesis of NO in melanoma patients.

Interleukin 12 (IL-12) is a cytokine with important regulatory functions bridging innate and adaptive immunity. It has been proposed as an immune adjuvant for vaccination therapy of infectious diseases and malignancies. The inflammatory properties of IL-12 play an important role in the adjuvant effect. We studied the effect of s.c. injections of recombinant human IL-12 (rHuIL-12) in 26 patients with renal cell cancer and demonstrated dose-dependent systemic activation of multiple inflammatory mediator systems in humans. rHuIL-12 at a dose of 0.5 microg/kg induced degranulation of neutrophils with a significant increase in the plasma levels of elastase (p < 0.05) and lactoferrin (p = 0.01) at 24 h. Additionally, rHuIL-12 injection mediated the release of lipid mediators, as demonstrated by a sharp increase in the plasma secretory phospholipase A2 (sPLA2) level (p = 0.003). rHuIL-12, when administered at a dose of 0.1 microg/kg, showed minimal systemic effects. In conclusion, when IL-12 is used as an adjuvant, doses should not exceed 0.1 microg/kg, in order to avoid severe systemic inflammatory responses

The introduction of paclitaxel/platinum combination chemotherapy and (interval) debulking surgery has significantly improved the prognosis of patients with ovarian cancer. Yet, many patients die of drug-resistant disease. Second-line chemotherapy may result in prolonged secondary remissions with alleviation of symptoms and improvement of quality of life. The response to second-line chemotherapy is strongly related to platinum sensitivity. More than 60% of platinum-sensitive patients respond to a re-challenge with platinum-containing chemotherapy. In platinum-resistant patients, on the contrary, the response rate to a re-challenge with 3-weekly platinum or any nonplatinum chemotherapy is less than 20%. The response to dose-dense weekly platinum-based regimens ranged from 48% to 64% in platinum-resistant patients. Moreover, the majority of the patients responded within 8 weeks after the start of the treatment. The progression-free survival ranged from a median of 5 months in a study using cisplatin/etoposide, to 11 months in a study with paclitaxel/carboplatin. The median survival was 11-15 months. The outpatient weekly paclitaxel/carboplatin regimen, with paclitaxel at a dose of 90 mg/m(2) and carboplatin at area under the curve 4, seems similarly effective and is better tolerated. Dose-dense weekly paclitaxel/carboplatin is an effective and well-tolerated therapy for platinum-sensitive, as well as platinum-resistant tumors. Responses to therapy are observed within 8 weeks in the majority of the patients. Whether a weekly regimen indeed is more effective than 3-weekly paclitaxel/carboplatin needs to be answered in a randomized study.

The purpose of this study was to determine the mechanism of the pharmacodynamic interaction between docetaxel/paclitaxel and cisplatin. Cisplatin- induced DNA-adducts and cisplatin accumulation were quantitated in peripheral blood leukocytes (WBC). The WBC were obtained from patients treated with docetaxel or paclitaxel in phase I/II studies and were incubated in vitro with cisplatin. In addition, blank whole-blood samples were obtained from pa- tients and healthy subjects and incubated in vitro with cisplatin or docetaxel/paclitaxel and cisplatin. The cis- platin-induced DNA-adduct levels measured in WBC after treatment with docetaxel or paclitaxel were signif- icantly lower than those determined in non-pretreated WBC. Docetaxel and paclitaxel reduced the intracellu- lar accumulation of cisplatin in WBC by 46—47%. If the pharmacodynamic interaction between docetaxel/pac- litaxel and cisplatin also occurs in other normal tissues such as bone marrow, it may well contribute to the sequence dependent toxicity that has been observed in clinical studies.

A prospective study was performed to investigate the combination of the aromatase inhibitor aminoglutethimide and hydrocortisone in androgen-independent prostate cancer with changes in prostate-specific antigen (PSA) level as main determinant for response. Thirty-five patients were treated with aminoglutethimide 1000 mg daily and hydrocortisone acetate 40 mg daily. PSA measurements were performed every month. If evaluable lesions were present, objective tumor assessment was done by computed tomography scan and X-ray investigations. In 12 patients (37%) the PSA value showed a confirmed response with a decline in serum level of at least 50%. Median time to progression in responding and all patients was 10.5 and 4.5 months, respectively. Median duration of response in responding patients was 9 months. Median survival for these two groups was 23 and 14.5 months, respectively. Of seven patients with measurable disease, two showed a partial response and five a stable disease. Improvement in general condition, pain and feeling of well-being was noted in two-thirds of patients. Therapy was well tolerated with mainly grade I and II adverse events in 20% of patients. We conclude that aminoglutethimide is a valuable second-line therapy for patients with androgen-independent prostate cancer.

Our objective was to study the influence of pegylated interferon-alpha2b (PEG-IFN-alpha) on the metabolism of amino acids and pteridines. We used an exploratory study into plasma concentrations of large neutral amino acids, 5-hydroxyindolacetic acid (5-HIAA), total biopterin (BIOP) and neopterin (NEOP) in 40 high-risk melanoma patients. Patients were randomized to treatment with PEG-IFN-alpha once a week in a dose of 6 microg/kg/week s.c. during 8 weeks, followed by a maintenance treatment of 3 microg/kg/week s.c. or to observation only. We found that treatment with PEG-IFN-alpha decreases tryptophan (TRP) concentrations in the first 3 months of treatment to a maximum of 25.3% compared to controls [95% confidence interval (CI): 14.9 to 34.4]. The TRP:LNAA ratio, an index for the availability of TRP to the central nervous system (CNS), decreases during 6 months with 18.8% (95% CI: 11.9 to 25.2). Concentrations of NEOP rose; however, concentrations of BIOP, the sum of tetrahydrobiopterin [BH4] and its oxidative products, did not decrease. The ratio of phenylalanine to tyrosine was increased with 11.7% (95% CI: 1.0 to 23.5) during 6 months. We conclude that, like conventional IFN-alpha, PEG-IFN-alpha lowers TRP concentrations and decreases the availability of TRP to the CNS. PEG-IFN-alpha has a similar influence on pteridine metabolism as standard IFN-alpha. If a lowered availability of TRP and a consequent decrease of serotonergic neurotransmission are indeed a mechanism underlying neuropsychiatric side-effects of IFN-alpha, patients on PEG-IFN-alpha are not at a lower risk of developing neuropsychiatric side-effects as patients on conventional IFN-alpha.

Brostallicin (PNU-166196) is a cytotoxic agent that binds to the minor groove of DNA with significant antitumor activity in preclinical studies. This trial was designed to determine the maximum tolerated dose, the toxicity profile, and the pharmacokinetics of Brostallicin in cancer patients.Patients were treated with escalating doses of Brostallicin ranging from 0.85 to 15 mg/m(2) administered as a 10-min i.v. infusion every 3 weeks. Blood samples for pharmacokinetic analysis were collected during the first and second course, and analyzed by liquid-chromatography with tandem-mass spectrometric detection.Twenty-seven evaluable patients received a total of 73 courses. Grade 4 neutropenia was the only dose-limiting toxicity at 12.5 mg/m(2), whereas grade 4 thrombocytopenia (1 patient) and grade 4 neutropenia (2 patients) were the dose-limiting toxicities at 15 mg/m(2). Other side effects, including thrombocytopenia and nausea, were generally mild. The maximum tolerated dose was defined at 10 mg/m(2). The clearance and terminal half-life of Brostallicin were dose-independent, with mean (+/-SD) values of 9.33 +/- 2.38 liters/h/m(2) and 4.69 +/- 1.88 h, respectively. There was no significant accumulation of Brostallicin with repeated administration. Significant relationships were observed between systemic exposure to Brostallicin and neutrophil counts at nadir. One partial response was observed in a patient with a gastrointestinal stromal tumor.Brostallicin was found to be well tolerated, with neutropenia being the principal toxicity. The recommended dose for additional evaluation in this schedule is 10 mg/m(2).

Immunotherapy with interferon-alfa (IFN-alfa) is used in a variety of diseases in- and outside clinical trials (e.g., chronic hepatitis, melanoma, chronic myelogenous leukemia, renal cell carcinoma, multiple myeloma). Treatment with IFN-alfa can cause (severe) neuropsychiatric side effects. The purpose of this article is to give an updated review of data on the incidence, manifestations and prediction of psychiatric side effects of immunotherapy with IFN-alfa. Furthermore, the article gives an overview of the management strategies and of the various theories on the pathophysiology of behavioural effects induced by cytokines.Use was made of computerized searches and of checking cross-references of articles and book chapters. The data on the incidence, manifestations and prediction are arranged by source of information, by target symptoms and by method of ascertainment.Different sources of information exist, e.g. adverse event reports of clinical trials, case descriptions and research specifically targeted on neuropsychiatric side effects. IFN-alfa is capable of inducing depressive symptoms and syndromes; the evidence for the induction of other psychiatric side effects is weaker. The depressive syndromes induced by IFN-alfa are in need of a more precise characterization. The results of studies on prediction of side effects are contradictory. Guidelines on managing psychiatric side effects predominantly arise from practical experience and common sense. Patient education plays a pivotal role. At this moment, there is no comprehensive theory on the pathophysiology of cytokine-induced psychiatric side effects.There is sufficient empirical support for a causal relation between IFN-alfa and the development of depressive symptoms and syndromes. Practical management of neuropsychiatric side effects begins before the start of therapy and should consist of repeated patient education, drug treatment and supportive measures. There are diverging theories on the pathophysiological backgrounds.

The aim of this study was to investigate whether expression of particular drug resistance genes in primary operable breast cancer correlates with response to first-line chemotherapy in advanced disease.We determined mRNA levels of BCRP, LRP, MRP1, MRP2, and MDR1 in 59 primary breast tumor specimens of patients who received chemotherapy as first-line systemic treatment after diagnosis of advanced disease. The relative expression levels were measured by quantitative real-time reverse transcription-PCR and subsequently analyzed in relation to the type of response to chemotherapy, the length of progression-free survival (PFS), and post-relapse overall survival.For each of these drug resistance genes, a large variation in expression level was observed among the tumors of the different patients. When analyzing mRNA expression in relation to overall response, it was found that the median expression level of these five drug resistance genes in the responding tumors, as compared with nonresponding tumors, was markedly lower. Classification of tumors as high versus low with respect to the expression level of these genes showed that the overall response in the MDR1-high subset (17%), as compared with the MDR1-low subset (68%), was significantly lower (P = 0.005). Although similar differences in response rate were found for subsets of tumors stratified by the expression level of the other drug resistance genes, none of the observed differences were statistically significant. However, in the subgroup of patients treated with anthracycline-based chemotherapy (5-fluorouracil, Adriamycin/epirubicin, and cyclophosphamide), a correlation between response and the expression of BCRP and MRP1 (only PFS) was found, whereas such an association was not present in the cyclophosphamide, methotrexate, and 5-fluorouracil-treated group of patients. Furthermore, high expression of LRP as well as MDR1 was found to be significantly associated with a poor PFS (P = 0.04 and P0.001, respectively). For lung resistance-related protein, this association was limited to 5-fluorouracil, Adriamycin/epirubicin, and cyclophosphamide. Expression levels of BCRP, MRP1, or MRP2 were not related with the length of PFS. Furthermore, no correlation between the expression level of these drug resistance genes and post-relapse overall survival was found.In this pilot study, MDR1 expression in primary breast tumors was inversely related with the efficacy of first-line chemotherapy, and high expression level was a significant predictor of poor prognosis for patients with advanced disease. Apart from MDR1, the expression levels of BCRP, LRP, and MRP1 might have some additional predictive value for clinical outcome.

Repeated administrations of recombinant human interleukin-12 (rHuIL-12) to cancer patients are characterized by a reduction of side effects during treatment. Induction of IFN-gamma, considered a key mediator of antitumor effects of IL-12, is known to decline on repeated administrations. We studied whether other immunological effects of rHuIL-12 are tapered in the course of treatment.In a Phase I study of 26 patients with advanced renal cell cancer, rHuIL-12 was administered s.c. on day 1, followed by 7 days rest and six injections administered over a 2-week time period. Plasma concentrations of various cytokines were monitored, as well as absolute counts of circulating leukocyte and lymphocyte subsets.The first injection of IL-12 was accompanied by rapid, transient, and dose-dependent increments of plasma levels IFN-gamma, tumor necrosis factor-alpha, IL-10, IL-6, IL-8, but not IL-4, as well as rapid, transient, and dose-dependent reductions of lymphocyte, monocyte, and neutrophil counts. The major lymphocyte subsets, i.e., CD4+ and CD8+ T cells, B cells, and natural killer cells, followed this pattern. On repeated rHuIL-12 injections, IL-10 concentrations increased further, whereas the transient increments of IFN-gamma, tumor necrosis factor-alpha, IL-6, and IL-8 concentrations, as well as the fluctuations of the leukocyte subset counts, were tapered. Dose escalation of IL-12 within clinically tolerable margins did not reduce the decline of these immunological effects.Induction of pro-inflammatory cytokines and associated fluctuations in leukocyte subset counts decrease on repeated administrations of rHuIL-12. The steady increment of IL-10 plasma levels may mediate the observed down-regulation of clinical and immunological effects.

The therapeutic potential of antitumor drugs is seriously limited by the manifestation of cellular drug resistance. We used the budding yeast Saccharomyces cerevisiae as a model system to identify novel mechanisms of resistance to one of the most active anticancer agents, cisplatin. We pinpointed NPR2 (nitrogen permease regulator 2) as a gene whose disruption conferred resistance to cisplatin. In addition, we observed a 4-fold cross-resistance of yeast npr2Delta cells (i.e., cells from which the NPR2 gene had been disrupted) to the anticancer drug doxorubicin, in combination with hypersensitivity to cadmium chloride. Furthermore, npr2Delta cells displayed unaltered cellular cisplatin and doxorubicin accumulation and showed an enhanced rate of spontaneous mutation compared with the isogenic parent. These data indicate that the npr2Delta phenotype overlaps that of the sky1Delta cells that we characterized previously (Mol Pharmacol 61:659-666, 2002). Therefore, we generated yeast npr2Delta sky1Delta double-knockout cells and performed clonogenic survival assays for cisplatin and doxorubicin, which revealed that NPR2 and SKY1 (SR-protein-specific kinase from budding yeast) are epistatic. The double-knockout strain was just as resistant to cisplatin and doxorubicin as the single-knockout strain that was most resistant to either drug. In conclusion, we identified NPR2 as a novel component involved in cell kill provoked by cisplatin and doxorubicin, and our data support the hypothesis that NPR2 and SKY1 may use mutual regulatory routes to mediate the cytotoxicity of these anticancer drugs.

To improve the curative success of chemotherapy, it will be essential to understand the molecular basis of drug resistance (DR) and sensitivity. We have developed a cell culture system that enables the functional cloning of mammalian DR genes based on phenotypic selection after overexpression of mammalian retroviral cDNA libraries and validated our system using the anticancer drug cisplatin. ERCC1-deficient and therefore cisplatin-hypersensitive mouse embryonic fibroblast target cells were transduced with a human placenta retroviral cDNA library. Subsequent cisplatin selection yielded 20 DR clones, each containing a recurring human ERCC1 gene. Surprisingly, nine of these clones contained 5′-truncated ERCC1 sequences that required alternative splicing of the vector sequence to encode a functional ERCC1 protein. The usage of cryptic splice sites in the vector sequence should be taken into consideration when interpreting results from retroviral gene expression applications, and might have consequences for the safe application of retroviral constructs in gene therapy.

Previously, a gender dependency of topotecan was found in the pharmacokinetics in the plasma compartment. Here, we prospectively studied the red blood cell (RBC) partitioning of topotecan and evaluated its consequences for overall drug disposition. Blood samples were obtained from 12 patients receiving cisplatin followed by i.v. topotecan. Topotecan pharmacokinetic analysis was performed in whole blood, plasma and RBCs. Significantly slower clearance was noted in females (n=7) compared to males (n=5) for lactone and total topotecan in plasma (p

It has been hypothesized that the paclitaxel vehicle Cremophor EL (CrEL) is responsible for nonlinear drug disposition by micellar entrapment. To gain further insight into the role of CrEL in taxane pharmacology, we studied the pharmacokinetics of paclitaxel in the presence and absence of CrEL after i.p. and i.v. dosing. Patients received an i.p. tracer dose of [G-(3)H]paclitaxel in ethanol without CrEL (100 microCi diluted further in isotonic saline) on day 1, i.p. paclitaxel formulated in CrEL (Taxol; 125 mg/m(2)) on day 4, an i.v. tracer of [G-(3)H]paclitaxel on day 22, and i.v. Taxol (175 mg/m(2)) on day 24. Four patients (age range, 54-74 years) were studied, and serial plasma samples up to 72 h were obtained and analyzed for total radioactivity, paclitaxel, and CrEL. In the presence of CrEL, i.v. paclitaxel clearance was 10.2 +/- 3.76 liters/h/m(2) (mean +/- SD), consistent with previous findings. The terminal disposition half-life was substantially prolonged after i.p. dosing (17.0 +/- 11.3 versus 28.7 +/- 8.72 h), as was the mean residence time (7.28 +/- 2.76 versus 40.7 +/- 13.8 h). The bioavailability of paclitaxel was 31.4 +/- 5.18%, indicating insignificant systemic concentrations after i.p. treatment. CrEL levels were undetectable after i.p. dosing (0.05 microl/ml), whereas after i.v. dosing, the mean clearance was 159 +/- 58.4 ml/h/m(2), in line with earlier observations. In the absence of CrEL, the bioavailability and systemic concentrations of i.p. paclitaxel were significantly increased. This finding is consistent with the postulated concept that CrEL is largely responsible for the pharmacokinetic advantage for peritoneal cavity exposure to total paclitaxel compared with systemic delivery.

An additional chromatographic peak was observed in plasma samples of patients receiving NX 211, a liposomal formulation of the topoisomerase I inhibitor lurtotecan. We have isolated and purified this product by sequential solid-phase extractions, and we report its structure and cytotoxicity relative to lurtotecan and related agents. Nuclear magnetic resonance data indicate that cleavage of the piperazino moiety occurred at the N-C bond of the B-ring, yielding 7-methyl-10,11-ethylenedioxy-20(S)-camptothecin (MEC). Tests of the growth inhibition potential of MEC in seven human tumor cell lines showed that the compound was approximately 2-18-fold more cytotoxic than lurtotecan, topotecan, and 7-ethyl-10-hydroxy-20(S)-camptothecin (SN-38). Subsequently, we found that MEC was the product of rapid photolysis of lurtotecan, with the rate of degradation inversely proportional to NX 211 concentrations, and greatly depends on light intensity. Furthermore, MEC concentrations were found to increase significantly in plasma samples exposed to laboratory light but not in blood. MEC was not produced from NX 211 in the presence of human liver microsomes, suggesting that it is not a product of cytochrome P-450 metabolism. Using a validated analytical method, trace levels of MEC were quantitated in blood samples of two patients. These observations confirm that the precautions for protection from light currently specified for preparation and administration of NX 211 dose solutions are critical. Procedures to minimize formation of MEC, by the use of amber vials for NX 211 and by preparation of dilutions immediately before clinical use in a fashion completely protected from light, are now being routinely implemented.

PURPOSE: To evaluate relationships between various body-size measures and irinotecan (CPT-11) clearance and metabolism in cancer patients, and to provide future dosing recommendations for this agent. PATIENTS AND METHODS: Pharmacokinetic data were obtained from 82 adult patients (50 men, 32 women; median age, 54 years) receiving CPT-11 as a 90-minute intravenous infusion (dose range, 175 to 350 mg/m2). In each patient, plasma samples were collected at timed intervals in the first administration of a 3-week schedule, and CPT-11 and its metabolite, SN-38, were measured by a liquid chromatographic assay. RESULTS: The mean (± SD) CPT-11 clearance was 33.6 ± 10.8 L/h, with an interindividual variability (IIV) of 32.1%. When clearance was adjusted for body-surface area (BSA), the IIV was similar (34.0%). In addition, in a multiple linear regression analysis, none of the studied measures (BSA, lean body mass, [adjusted] ideal body weight, and body mass index) was a significant covariate (P > .13; r2 < .014) in our population. Similarly, BSA did not significantly contribute to variability in the relative extent of conversion to SN-38 (P = .26). CONCLUSION: BSA is not a predictor of CPT-11 clearance or SN-38 pharmacokinetics and does not contribute to reducing kinetic variability. These findings provide a rationale for the conduct of a comparative phase III study between BSA-based dosing and flat or fixed dosing of CPT-11.

Piritrexim is a lipid-soluble inhibitor of dihydrofolate reductase (DHFR) that enters tumour cells rapidly by passive diffusion, cannot be polyglutamated, and is as effective as methotrexate in inhibiting DHFR. Bioavailability after oral dosing is approximately 75%. We performed a phase II study with oral piritrexim in non-chemotherapy pretreated patients with metastatic urothelial cancer. Thirty-three patients were treated with 25 mg three times daily for 5 consecutive days, repeated weekly, with provision for dose escalation or reduction according to the toxicity observed. Of 29 evaluable patients, one patient achieved a complete response of 19+ weeks duration, and ten patients achieved a partial response with a median duration of 22 weeks (range 16-48), for a total response rate of 38%. Piritrexim was generally well tolerated, with myelosuppression as the major toxicity, that frequently required dose modification. We conclude that piritrexim appears to be an active agent in patients with metastatic urothelial cancer when administered as a 5-day, low-dose oral schedule. It would be attractive to investigate the combination of piritrexim and cisplatin.

Nonlinear disposition of paclitaxel (Taxol) in cancer patients has been described in several studies, but the underlying mechanism is still a matter of speculation. Previously, we have shown in vitro that the paclitaxel formulation vehicle, Cremophor EL (CrEL), alters the blood distribution of paclitaxel as a result of entrapment of the compound in circulating CrEL micelles, thereby reducing the free drug fraction available for cellular partitioning. Based on these findings, we prospectively re-evaluated the linearity of paclitaxel disposition in patients using whole blood and plasma analysis, and sought to define a new pharmacokinetic model to describe the data. Seven patients with solid tumors were treated with paclitaxel infused over 3 h, each at consecutive 3-weekly dose levels of 225, 175 and 135 mg/m2 (CrEL dose level, 18.8, 14.6, and 11.3 ml/m2, respectively). Patient samples were collected up to 24 h after the start of infusion, and analyzed by high-performance liquid chromatography. Paclitaxel peak levels and areas under the curve in whole blood increased linearly with dose, whereas plasma levels showed substantial deviation from linearity. This was shown to be caused by a CrEL concentration-dependent decrease in paclitaxel uptake in blood cells, as reflected by the blood:plasma concentration ratios which altered significantly from 0.83 +/- 0.11 (at 135 mg/m2) to 0.68 +/- 0.07 (at 225 mg/m2). It is concluded that the nonlinear disposition of paclitaxel is related to paclitaxel dose-related levels of the formulation vehicle CrEL, leading to a disproportionate drug accumulation in the plasma fraction. The pharmacokinetic model developed accurately described the data, and will help guide future development and refinement of clinical protocols, especially in defining the exposure measure best linked to paclitaxel effects and toxicities.

The ether lipid miltefosine (hexadecylphosphocholine) was orally given to patients with various tumours in a dose-finding study. All patients initially received a daily total dose of 100 mg, which in the absence of side-effects was increased to 150 mg and further to 200 mg. A total of 54 patients were entered and were evaluable for gastrointestinal toxicity. Nausea and vomiting were found to be dose-limiting; 22% of patients ultimately tolerated a dose of 100 mg, 59% tolerated a dose of 150 mg and 19% tolerated a dose of 200 mg. In addition 30% of patients developed renal dysfunction, which was thought to be related to the drug. No other toxicities were observed. For further phase II studies it is recommended that one starts with a dose of 150 mg daily, divided over three administrations.

47 patients with advanced urothelial cancer and no prior chemotherapy were randomly assigned to therapy with either carboplatin or iproplatin. Both platinum analogues were administered intravenously every 28 days at doses of 400 mg/m 2 carboplatin and 300 mg/m 2 iproplatin. None of 14 evaluable patients treated with carboplatin responded. Therefore, this arm was closed and from then on all eligible patients were registered on the iproplatin arm. 5 of 29 evaluable patients treated with iproplatin achieved a partial response (17%) for a median duration of 27 weeks (range 22–37). Iproplatin did not induce renal function disturbance. Gastrointestinal toxicity was mild to moderate. Bone marrow toxicity predominantly consisted of thrombocytopenia and required platelet transfusions in 13% of patients. 2 patients developed hypersensitivity reactions. It is concluded that the bone marrow toxicity and the chance of hypersensitivity render iproplatin an unattractive alternative to cisplatin.

A multicentre study of IL2 and IFN alpha has been performed in 58 patients with metastatic melanoma. The scheme consisted of IL2 3.0 BRMP MU/m2/d as a continuous infusion for 4 d combined with subcutaneous administration of IFN alpha 6 MU/m2/d, day 1 + 4. The cycle was repeated every 2 weeks for a maximum duration of 26 weeks. 54 patients were evaluable for response. One (2%) achieved a complete and 10 (19%) a partial response. 19 (35%) patients were stable and 24 (44%) showed progressive disease. Common side-effects included fever, chills, fatigue, skin rash, anorexia, nausea and diarrhoea. Hypothyroidism was noted in 10% of the patients. These results show that this regimen of IL2 and IFN alpha is active but, in contrast to what could be expected, not superior to IL2 alone possibly due to suboptimal dosing. In an ongoing study in Rotterdam and Nijmegen, a more intense schedule was chosen, consisting of three daily i.v. doses of IL2 4.5 BRMP MU/m2 and IFN alpha 3.0 MU/m2 for 5 d. This regimen is repeated at intervals of 3 weeks for a total of three cycles. Presently, nine patients have been entered. One patient achieved a complete response, four a partial response (overall 56%), three had stable disease and one progressed. Toxicity was severe and treatment was prematurely stopped in five patients: myocardial infarction (one patient), atrial fibrillation (one patient), negative T waves and myocardial hypokinesia (one patient) and psychosis (two patients). This regimen can only be justified if the therapeutic results are superb, which has yet to be awaited.

A high-performance liquid chromatographic assay with fluorescence detection has been developed for the determination of doxorubicin and its metabolite doxorubicinol in plasma of cancer patients. Quantitative extraction was achieved by a single protein-precipitation step of 1-ml samples with 500 microl of acetone in the presence of 100 microl of zinc sulfate [70% (w/v) in water]. Doxorubicin and doxorubicinol were separated isocratically on a column packed with Inertsil ODS-80A material and a mobile phase composed of water:acetonitrile:tetrahydrofuran (76:24:0.5, v/v/v). The related compound daunorubicin was used as internal standard. The column effluent was monitored fluorimetrically at an excitation wavelength of 480 nm and an emission wavelength of 560 nm, with a band width of 40 nm. The calibration graphs of doxorubicin and doxorubicinol were linear over a range of 1.0 to 100 and 0.50 to 50. 0 ng/mL, respectively, with lower limits of quantitation of 1.0 and 0.50 ng/ml. Results obtained from a 4-day validation study demonstrated excellent accuracy (91.0-106%) and precision (0.90-10. 2%) across the calibration ranges for both compounds. The developed method has been applied extensively to a clinical study to examine the pharmacokinetics and metabolism of doxorubicin in patients cotreated with a potent inhibitor of MDR1 P-glycoprotein activity, GF120918.

The induction of apoptosis by diverse apoptotic stimuli was studied in a panel of 6 testicular germ cell tumour(TGCT) cell lines with defined p53 status. Although the sensitivity to a particular stimulus varied considerably among the TGCT cell lines, the differences in response were not associated with the presence of functional p53. Mutant (mt) p53-expressing NCCIT and S2 (no p53 protein) were both readily triggered into apoptosis by cisplatin and doxorubicin, while wild-type(wt)-p53-transactivation-competent 2102 EP cells failed to undergo drug-induced apoptosis. Moreover, transactivation-deficient NCCIT cells and wtp53-expressing NT2 cells were equally sensitive to cisplatin, doxorubicin, gamma radiation, and cell-permeable C2-ceramide. Our p53 data suggest that, at least in this panel of non-isogeneic TGCT cell lines, hypersensitivity to therapeutic agents is not associated with p53 status. Next, we examined the impact of p53 inactivation on apoptosis induction in isogeneic NT2 sublines expressing human papillomavirus E6 protein. Evidently, abrogation of p53 function did not affect the hypersensitivity to apoptotic stimuli. We noted that drug-sensitive S2 cells were highly resistant to radiation-induced apoptosis, indicating distinct signalling pathways for chemotherapy and irradiation. The impaired radiation-induced apoptotic pathway in S2 and 2102 EP could not be restored by addition of cell-permeable C2-ceramide, suggesting that the blockade is downstream of ceramide generation. Ligation of Fas/APO-1/CD95 by anti-Fas effectively induced apoptosis in Fas-antigen expressing S2, 2102 EP and 833 KE. The efficient Fas-mediated activation of apoptosis in drug-, radiation-, and ceramide-resistant 2102 EP cells further suggests that diverse apoptosis-inducing factors may use distinct signalling pathways. In summary, we demonstrated the presence of distinct p53-independent apoptotic pathways in TGCT cells. Int. J. Cancer 81:620–628, 1999. © 1999 Wiley-Liss, Inc.

7-Ethyl-10-hydroxycamptothecine (SN-38) is the active metabolite of the topoisomerase I inhibitor and antineoplastic agent, irinotecan (CPT-11). Here, we present a new and sensitive reversed-phase high-performance liquid chromatographic method for the determination of SN-38 in human plasma samples. Sample pretreatment involves a protein precipitation of 1-mL samples with 2 mL of acetonitrile, followed by a one-step solvent extraction with 5 mL of chloroform, with camptothecine used as internal standard. Chromatographic separation was achieved on an analytical column packed with Hypersil ODS material (100 x 4.6 mm i.d., 5 microm P.S.), and isocratic elution with a mixture of acetonitrile:0.1 M ammonium acetate containing 10 mM tetrabutylammonium sulfate (23:77, v/v), pH 5.3 (hydrochloric acid). The column effluent was monitored at excitation and emission wavelengths of 380 and 556 nm, respectively. The limit of quantitation of the method presented was at the low femtomole level ( approximately 8.4 fmol; equivalent to 5 pg/mL), with the standard curves being linear over nearly three orders of magnitude. Intraassay precision was9%, while interassay variations were between 2 and 5%. The extraction efficiency was concentration independent and averaged 88.0 +/- 14.3% (mean +/- standard deviation; n = 59). The described method will be used in future studies to assess the extent of enterohepatic recirculation of SN-38 in cancer patients following intravenous CPT-11 treatment.

Testicular cancer is the most frequent malignant disease in men aged 15–40 years. Due to its sensitivity to chemotherapeutic drugs, most patients, including those with widespread metastatic disease, can now be cured. Bleomycin is an essential component of the most effective chemotherapy regimen for testicular cancer—ie, bleomycin, etoposide, and cisplatin [BEP].1 However, bleomycin is feared for its induction of bleomycin-induced pneumonitis (BIP), which is sometimes fatal.2 After reports in the 1980s of perioperative complications that were ascribed to bleomycin, high inspired-oxygen fractions during anaesthesia were avoided, as were high inspired-oxygen fractions under hyperbaric circumstances, such as scuba diving.

Docetaxel is a new antimicrotubule agent that induces a predominantly sensory neuropathy that is mild in most patients. This prospective study was performed to determine if corticosteroid co-medication reduces the incidence and severity of docetaxel-induced neuropathy. Two groups of patients treated with docetaxel in subsequent cohorts were prospectively analyzed for neurotoxicity. Group A consisted of 38 patients with a variety of solid tumors, who were treated in studies before corticosteroid co-medication was recommended, while 49 female patients in group B with metastatic breast cancer were treated after co-medication with corticosteroids was introduced as a routine. Neuropathy was evaluated by a clinical sum-score for symptoms and signs, and by measurement of the vibration perception threshold (VPT). The severity of neuropathy was graded according to NCI Common Toxicity Criteria. In 42% of patients of group A and in 65% of patients of group B a mainly mild neuropathy was documented. There was no statistically significant difference in neurotoxicity between group A and B. The cumulative dose of docetaxel showed a significant correlation with post-treatment scores of VPT, sensory sum-score, grade of paresthesias, and grade of neurosensory and neuromotor toxicity. Corticosteroid co-medication does not reduce the development of docetaxel-related neuropathy.

We investigated the efficacy and toxicity of induction chemotherapy with cisplatin and etoposide with either bleomycin or ifosfamide in patients with intermediate-prognosis testicular non-seminoma. A total of 84 eligible patients were randomized to receive four cycles of etoposide, ifosfamide, cisplatin (VIP), or four cycles of bleomycin, etoposide, cisplatin (BEP). Intermediate prognosis was defined as any of the following: lymph node metastases 5-10 cm in diameter, lung metastases more than four in number or > 3 cm, HCG 5000-50 000 IU l(-1), AFP > 1000 IU l(-1). The complete response (CR) rates to VIP and BEP were similar, 74% and 79% respectively (P = 0.62). Including the cases in whom viable cancer was completely resected with post-chemotherapy debulking surgery, the percentages of patients who achieved a no-evidence-of-disease status were 80% on VIP and 82% on BEP (P = 0.99). In addition, there were no differences in relapse rate, disease-free and overall survival after a median follow-up of 7.7 years. The 5-year progression-free survival was 85% (95% CI 74-96%) in the VIP arm and 83% (95% CI 71-96%) in the BEP arm, hazard ratio (VIP/BEP) 0.83 (95% CI 0.30-2.28). The VIP regimen was more toxic with regard to bone marrow function; the frequency of leucocytes below 2000 mu l(-1) throughout four cycles was 89% on VIP and 37% on BEP (P

An isocratic reversed-phase high-performance liquid chromatographic method with ultraviolet detection at 230 nm has been developed for the determination of paclitaxel in human plasma. Plasma samples were prepared by a selective one-step liquid-liquid extraction involving a mixture of acetonitrile-n-butyl chloride (1:4, v/v). Paclitaxel and the internal standard docetaxel were separated using a column packed with ODS-80A material, and a mobile phase consisting of water-methanol-tetrahydrofuran-ammonium hydroxide (37.5:60:2.5:0.1, v/v). The calibration graph for paclitaxel was linear in the range 10-500 ng/ml, with a lower limit of quantitation of 10 ng/ml, using 1 ml plasma samples. The extraction recoveries of spiked paclitaxel and docetaxel to drug-free human plasma were 89.6+/-8.52 and 93.7+/-5.0%, respectively. Validation data showed that the assay for paclitaxel is sensitive, selective, accurate and reproducible. The assay has been used in a single pharmacokinetic experiment in a patient to investigate the applicability of the method in vivo.

DNA adducts formed by cisplatin [cis-diamminedichloroplatinum(II)] were measured in blood samples from 48 testicular cancer patients treated in four centers in Europe during four six cycles with cisplatin infusions on five successive days (total samples, 112). Total protein-bound platinum (Pt) in blood was also measured (total samples, 84). The mean on main DNA adduct, cis-Pt(NH3)(2) d(pGpG) (Pt-GG), was 0.75 fmol/mu g DNA [standard deviation (SD) = 0.66] on the first day of the first cycle, increased after the infusion at day 5 of the cycle (mean 1.74 fmol/mu g DNA, SD = 0.90) and decreased on the following day (mean 1.09 fmol/mu g DNA, SD = 0.62). In subsequent cycles, there was a tendency to an increase in the mean Pt-GG levels. The values of protein-bound Pt in blood showed little reduction between day 5 and 6 of each cycle, and a stable increase during the course of the therapy. Strong correlations were seen between day 1, 5 and 6 of the first cycle for both Pt-GG and protein-bound Pt in blood. A strong correlation (r = 0.62, p

In this article we review the in vivo model systems that have been developed for studying P-glycoprotein-mediated multidrug resistance (MDR) in the preclinical setting. Rodents have two mdr genes, both of which confer the MDR phenotype: mdr 1a and mdr 1b. At gene level they show strong homology to the human MDR1 gene and the tissue distribution of their gene product is very similar to P-glycoprotein expression in humans. In vivo studies have shown the physiological roles of P-glycoprotein, including protection of the organism from damage by xenobiotics. Tumors with intrinsic P-glycoprotein expression, induced MDR or transfected with an mdr gene, can be used as syngeneic or xenogenic tumor models. Ascites, leukemia, and solid MDR tumor models have been developed. Molecular engineering has resulted in transgenic mice that express the human MDR1 gene in their bone marrow and in knockout mice missing a murine mdr gene. The data on pharmacokinetics, efficacy, and toxicity of chemosensitizers of P-glycoprotein in vivo are described. Results from studies using monoclonal antibodies directed against P-glycoprotein and other miscellaneous approaches for modulation of MDR are mentioned. The importance of in vivo studies prior to clinical trials is being stressed and potential pitfalls due to differences between species are discussed.

Purpose: Testicular germ cell tumors (TGCTs) represent one of the few tumor types that are curable by antineoplastic therapy, probably due to the high sensitivity of this neoplasm to induction of apoptosis by chemotherapeutic agents and/or ionizing radiation. Here, we tested cell susceptibility to radiation-induced apoptosis in a panel of TGCT cell lines and attempted to correlate this with the known potentially relevant molecular determinants (p53 gene status and Bcl-2 family proteins) of apoptosis. Methods and Materials: Induction of apoptosis by γ-radiation was morphologically recognized in NT2, NCCIT, S2, and 2102 EP using Hoechst/PI staining and additionally confirmed by Western blot analysis of PARP cleavage. The p53 gene status was estimated by sequence analysis. Expression of p21/WAF/CIP was determined by Northern blot analysis and immunoblotting was used to monitor p53, Bax, Bcl-2, Bcl-x, and Bak protein levels. In vitro colony formation was studied to establish clonogenic survival curves. Results: NT2 and NCCIT appeared to be susceptible for radiation-induced apoptosis, contrasting 2102 EP and S2 which were highly resistant. Sequence analysis showed that NT2, S2, and 2102 EP are homozygous for wild-type p53 (wtp53), whereas NCCIT contains mutant p53 (mtp53). NT2 and 2102 EP cells showed radiation-induced p53 upregulation, while NCCIT (mtp53) and S2 (no p53 protein) cells did not. Consistently, γ-radiation-induced DNA damage resulted in a p53-dependent transactivation of the p21/WAF/CIP gene in NT2 and 2102 EP, but not in mtp53-containing NCCIT cells and p53 nonexpressing S2 cells. Constitutive expression of Bax, Bcl-2, Bcl-x, and Bak was not affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis. A discrepancy was found between apoptosis and reproductive death. Conclusions: The present study revealed that: i) the presence of wtp53 may not be absolutely required for the hypersensitivity for radiation-induced apoptosis in TGCT cell lines, ii) the molecular mechanism underlying the unique radiosensitivity was independent of the expression of Bcl-2 family proteins, and iii) cell susceptibility to apoptosis induction is not sufficiently informative to predict intrinsic radiosensitivity as determined by clonogenic survival.

We investigated the role of p53 and of the Bcl-2 family proteins in the apoptotic response of a panel of testicular tumour cell lines (NT2, NCCIT, S2 and 2102 EP). The p53 gene status and the capacity of the p53 protein to transactivate the p21/WAF/CIP gene were determined, and we examined the correlation between p53 status and the susceptibility to cisplatin-induced apoptosis. In contrast to wild-type p53-containing NT2 and 2102 EP cells, NCCIT (mutant p53) and S2 (no p53 protein) cells were shown to be p53-transactivation defective. However, NCCIT and S2 cells with non-functional p53 were readily triggered into apoptosis by cisplatin, whereas p53-transactivation competent 2102 EP cells failed to undergo cisplatin-induced apoptosis. The defective apoptotic pathway in 2102 EP cells was reflected by a 4-fold decreased sensitivity to cisplatin in the MTT assay. We further demonstrated that the p53-independent differential cisplatin sensitivity among the testicular germ cell tumour (TGCT) cell lines was not due to differences in cellular cisplatin accumulation or DNA platination. The pattern of endogenous expression levels of Bax, Bcl-2, Bcl-x and Bak, which was not modulated by cisplatin treatment, demonstrated that these Bcl-2 family proteins are not involved in drug-induced apoptosis in the TGCT cell lines. Our results suggest a lack of correlation between cisplatin-induced apoptosis, p53 status and expression of Bcl-2 family proteins in our panel of TGCT cell lines. We conclude that the cisplatin-induced apoptotic pathway in TGCT cell lines might be p53-independent and is probably not associated with differences in the Bcl-2/Bax rheostat.

PURPOSE This prospective randomized trial was designed to compare the efficacy of etoposide plus cisplatin (EP) versus bleomycin, etoposide, and cisplatin (BEP) chemotherapy in patients with good-prognosis metastatic nonseminomatous testicular cancer. PATIENTS AND METHODS Four hundred nineteen patients with good-prognosis nonseminomatous testicular cancer were randomized to receive four cycles of cisplatin 20 mg/m2 on days 1 to 5 plus etoposide 120 mg/m2 on days 1, 3, and 5 with or without bleomycin 30 mg weekly. RESULTS Of 395 eligible patients, 169 of 195 patients allocated to EP (87%) and 189 of 200 patients allocated to BEP (95%) achieved a complete response with chemotherapy alone or after postchemotherapy surgery. These results are significantly different (P = .0075). After a median follow-up duration of 7.3 years, eight patients (4%) on each treatment arm relapsed. In view of the low number of unfavorable treatment outcomes (11%), no significant differences were detected in time to progression (P = .136) and survival (P = .262). Both the acute and late pulmonary toxicity and neurotoxicity were significantly greater in patients who received BEP, whereas Raynaud's phenomenon occurred exclusively in patients who received BEP (P < .001). Two patients treated with BEP died of bleomycin pulmonary toxicity. CONCLUSION BEP is the most effective combination regimen in the treatment of disseminated nonseminomatous germ cell cancer. In this particular BEP regimen with etoposide at a dose of 360 mg/m2 per cycle, even in good-prognosis patients, bleomycin cannot be deleted without compromising treatment efficacy, but its use is associated with more toxicity (particularly pulmonary) and efforts to reduce this merit further exploration.

Expression of the apoptosis-associated proteins Bcl-2 and Bax was quantitated by flow cytometry (FCM) in chemosensitive testicular germ-cell tumor NT2 cells, and the results were compared with those obtained by Western blotting. NT2 cells were incubated with cisplatin (3.1 μM for 2 h at 37°C), and 24, 48, and 72 h later were analyzed for induction of apoptosis, and for modulation of the expression of cell death suppressing protein Bcl-2, as well as cell death promoting protein Bax. Apoptosis was quantitated by binding of annexin V conjugated with fluorescein isothiocyanate (FITC) to the cell membrane. Cisplatin-treatment induced apoptosis in NT2 cells. The apoptotic cell population increased in time, and at t = 72 h after drug incubation, about 90% of cells that were present in the cell culture were apoptotic. Subsequently, we determined the expression of the Bcl-2 and Bax proteins by FCM and Western blotting before and after drug treatment. NT2 cells had low constitutive expression levels of Bcl-2 and elevated constitutive expression levels of Bax protein, as determined by both methods. At t = 24 h and 48 h after drug treatment, no changes were observed in the expression of the Bcl-2 protein, as quantitated by FCM and Western blotting. Also, the expression of the Bax protein had not changed, based on Western blotting. However, FCM revealed that in a specific subpopulation of drug-treated NT2 cells, Bax expression was increased. On the basis of forward and perpendicular light-scatter this subpopulation, which consisted of large, early apoptotic, swollen cells with increased internal complexity, was sorted, and showed abundant Bax protein by FCM and Western blotting. Our results demonstrate that the chemosensitivity of NT2 cells is probably due to a low intrinsic threshold for drug-induced apoptosis that is accompanied by overexpression of the death-promoting Bax protein during the early stages of the apoptotic process. We conclude that FCM is superior to Western blotting for the detection of heterogeneous expression of Bax in a given cell population. Cytometry 27:275–282, 1997. © 1997 Wiley-Liss, Inc.

We investigated the prognostic value of the serum half-life of human chorionic gonadotrophin (HCG) and alpha-fetoprotein (AFP) during induction chemotherapy and the relative prognostic importance of initial marker concentrations and marker half-life. Marker half-lives were calculated using two abnormal values observed between day 8 and day 22 of the first chemotherapy cycle, Moreover, analyses were carried out using day 43 as the second measurement point. Treatment failure at any time was chosen as the end point. The relative prognostic influence of marker half-lives and initial marker concentrations was tested in univariate and multivariate analyses. Half-lives were considered to be prolonged ii > 3 days for HCG and > 6 days for AFP. In addition, we separated patients into those with half-lives > 6 days for HCG and those with half-lives > 10 days for AFP to examine whether these long half-lives were associated with a poor prognosis. A group of 669 patients treated with cisplatin combination chemotherapy was studied. Forty-two per cent of the patients had normal HCG and 37% had normal AFP at the start of chemotherapy. At day 22, HCG was still elevated in 138 patients and AFP in 211, At day 43, the numbers of these patients were 35 and 80 respectively. Based on the measurements obtained on day 8 and day 22, a half-life of HCG > 3 days or > 6 days and/or a half-life AFP > 6 days or > 10 days did not accurately predict treatment failure (P=0.413 and P=0.851, respectively; values obtained using tests for trend). However, initial marker concentrations of HCG and/or AFP greater than or equal to 1000 IU l(-1) were highly significant prognosticators for treatment failure (P=0.001 and P

The pharmacokinetics of oral dexniguldipine, a new multidrug-resistance-modifying agent under clinical evaluation, and its pyridine metabolite M-1 were determined in plasma, tumor, and renal tissue in Wag/Rij rats bearing a multidrug-resistant CC531 colon adenocarcinoma tumor under the renal capsule. The pharmacokinetics were studied in four experiments. After a single administration of dexniguldipine (30 mg/kg), tumors and kidneys were collected after 5 (experiment 1), 24 (experiment 2), and 48 h (experiment 3). In the fourth experiment, dexniguldipine was given once daily for 3 consecutive days at a dose of 30 mg/kg. In all experiments, plasma samples were collected at regular intervals. The concentrations of dexniguldipine and M-1 could be determined in plasma in most of the rats at up to 32 h after drug administration. The area under the curve (AUC) of dexniguldipine and M-1 varied by a factor of 2-6 in the four experiments. High tumor-tissue concentrations of dexniguldipine were observed. The concentrations were highest in the multiple-dose experiment (2014 +/- 1005 ng/g tissue). High degrees of correlation (> 0.8) were established between the concentrations of dexniguldipine measured in plasma and tumor as well as renal tissue. Overall, tumor-tissue concentrations of M-1 comprised one-third of the dexniguldipine concentrations measured.

Sensitive high-performance liquid chromatographic assays have been developed to determine the levels of the lactone and lactone plus carboxylate (total) forms of the antitumor agent irinotecan (CPT-11) and its active metabolite SN-38, in human plasma. The related compound camptothecin was used as the internal standard. The selective sample pretreatment for the lactone forms involved a single solvent extraction with acetonitrile-n-butyl chloride (1:4, v/v), whereas the sample clean-up for the total forms was a simple protein precipitation with aqueous perchloric acid-methanol (1:1, v/v), which results in the conversion of the carboxylate to the lactone forms. Chromatography was carried out on a Hypersil ODS column, with detection performed fluorimetrically. The methods have been validated, and stability tests under various conditions have been performed. The lower limits of quantitation are 0.5 and 2.0 ng/ml for the lactone and total forms, respectively. The assays have been used in a single pharmacokinetic experiment in a patient to investigate the applicability of the method in vivo.

In stage I non-seminomatous testicular cancer, the decision between surveillance and adjuvant chemotherapy rests heavily upon the valuation of quality of life. Decision analysis was used to assess at what relapse rate adjuvant chemotherapy is preferred when patients' and clinicians' evaluations are considered. Probabilities were obtained from the literature and from experts. Evaluations of the disease states were obtained from patients (n = 68) and clinicians (n = 50). Results from the model were compared with a treatment preference question, asking for the relapse rate directly. Adjuvant chemotherapy was preferred at relapse rates above 50% when patient evaluations were used. The evaluations of the disease states had a strong impact on the decision. Using clinician evaluations, adjuvant chemotherapy was preferred at relapse rates above 73%. The relapse rates from the treatment preference question were lower: 46% for patients and 35% for clinicians. The results indicate that when patient preferences are accounted for, adjuvant chemotherapy should be considered more often.

The presence of multidrug resistant cells, either acquired or de novo, severely limits treatment outcome in haematological malignancies. Although expression of the Mr 170,000 P-glycoprotein drug pump is likely to play a role in multidrug resistance (MDR) in haematological malignancies, it is now evident that other MDR mechanisms may be operational as well in leukaemias, lymphomas, and multiple myeloma. We determined the expression of a newly recognised drug resistance gene, the Multidrug Resistance-associated Protein (MRP) gene, in peripheral blood cells from healthy volunteers and from patients with haematological malignancies. Expression of MRP mRNA and its Mr 190,000 glycoprotein were estimated by RNase protection assay and immunocytochemistry, respectively. MRP appeared to be ubiquitously expressed at low levels in all nonmalignant haemopoietic cell types. However, some leukaemias showed elevated levels of MRP, probably due to transcriptional activation or increased mRNA stability. High to very high MRP expression levels were frequently found in chronic lymphocytic leukaemia and prolymphocytic leukaemia. Acute myelocytic leukemia often exhibited low but occasionally high MRP expression levels, while in the other acute and chronic leukaemias, lymphomas, and multiple myeloma, predominantly low, basal levels of MRP were found. We conclude that hyperexpression of MRP is observed in leukaemias, and that further studies are needed to assess the clinical relevance of MRP.

Article abstract-Docetaxel, a new semisynthetic taxoid used as an antineoplastic agent, induced a predominantly sensory neuropathy in 20 of 41 patients. We assessed neurotoxicity in all patients participating in four phase II trials conducted in our institution. The neuropathy was evaluated by a clinical sum-score for symptoms and signs and by measurement of the Vibration Perception Threshold (VPT). The severity of neuropathy was graded according to the National Cancer Institute's Common Toxicity Criteria. Neuropathic symptoms were mild in most patients. However, at cumulative doses above 600 mg/m2, 3 of 15 patients developed a moderate and 1 of 15 patients a severe neuropathy. There was a significant correlation between the cumulative dose of docetaxel and the post-treatment sum-score (p = 0.002). We found no correlation between post-treatment VPT and clinical sum-score or between post-treatment VPT and the cumulative dose of docetaxel. We conclude that docetaxel produces a mild and predominantly sensory neuropathy in a high proportion of treated patients. This neurotoxicity appeared to be dose dependent and may be severe and disabling at higher dose levels. Determination of the VPT is not a reliable method to monitor docetaxel-induced neuropathy.NEUROLOGY 1996;46: 104-108

Sample preparation for the measurement of non-protein-bound platinum was evaluated by precipitation of plasma proteins with cold ethanol. The method was compared with the routinely used plasma ultrafiltration and with trichloroacetic acid (TCA) protein precipitation. After incubation of human plasma samples with cisplatin or carboplatin, unbound platinum concentrations were determined applying Amicon Diaflo ultrafiltration membranes and Millipore ultrafree-MC filters. For protein precipitation, 1 ml of cold (-20 degrees C) pure ethanol was added to 0.5 ml of human plasma and the supernatant was collected after 2 h, or 0.5 ml of cold 20% TCA was added to 0.5 ml of plasma. Platinum was analyzed by atomic absorption spectrophotometry (AAS). There was no significant difference between the ethanol and ultrafiltration methods in the unbound platinum concentration. The protein content in the supernatant (1.00 +/- 0.20%) was slightly higher than that in the Amicon (0.58 +/- 0.05%) and Millipore (0.55 +/- 0.04%) ultrafiltrates. On average, the TCA and ethanol method seemed to be equally appropriate. The ethanol precipitation method is concluded to be simple, convenient, and reproducible and has negligible costs.

PURPOSE To determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF) used in addition to standard inpatient antibiotic therapy shortens the period of hospitalization due to chemotherapy-induced neutropenic fever. PATIENTS AND METHODS One hundred thirty-four patients with a hematologic (n = 47) or solid tumor (n = 87) who had severe neutropenia (< 0.5 x 10(9)/L) and fever (> 38.5 degrees C once or > 38 degrees C twice over a 12-hour observation period) were randomly assigned to receive GM-CSF 5 micrograms/kg/d (n = 65) or placebo (n = 69) in conjunction with broad-spectrum antibiotics for a minimum of 4 days and a maximum of 14 days. GM-CSF/placebo and antibiotics were stopped if the neutrophil count was greater than 1.0 x 10(9)/L and temperature less than 37.5 degrees C during 2 consecutive days, or for a leukocyte count > or = 10 x 10(9)/L, both followed by a 24-hour observation period (hospitalization period). RESULTS Compared with placebo, GM-CSF enhanced neutrophil recovery. Median neutrophil counts at day 4 were 2.5 x 10(9)/L (range, 0 to 25) in the GM-CSF arm and 1.3 x 10(9)/L (range, 0 to 9) in the placebo arm (P < .001). No significant difference was observed with regard to median number of days with less than 1.0 x 10(9)/L neutrophils (4 v 4) or days of fever (3 v 3). The median number of days patients were hospitalized while on study was comparable in the GM-CSF and placebo groups at 6 (range, 3 to 14) versus 7 (range, 4 to 14), respectively, according to an intention-to-treat analysis (P = .27). Quality-of-life scores in 90 patients demonstrated significant differences in favor of the placebo group. Hospital costs were significantly higher for GM-CSF-treated patients if GM-CSF was included in the price (median costs, $4,140 [US] for GM-CSF v $590 for placebo; P < .05). CONCLUSION These results indicate that GM-CSF does not affect the number of days for resolution of fever or the hospitalization period for this patient group, although a significant effect of GM-CSF was observed on neutrophil recovery.

The chemosensitizing potency of dexniguldipine hydrochloride (B8509-035) on epidoxorubicin was assessed in a multidrug-resistant (MDR) tumour model, the intrinsic MDR rat colon carcinoma CC531. In vitro in the sulphorhodamine B cell-viability assay the cytotoxicity of epidoxorubicin was increased approximately 15-fold by co-incubation with 50 ng/ml dexniguldipine. In vivo concentrations of dexniguldipine 5 h after a single oral dose of 30 mg/kg were 72 (+/- 19 SD) ng/ml in plasma and 925 (+/- 495 SD) ng/g in tumour tissue. Levels of the metabolite of dexniguldipine, M-1, which has the same chemosensitizing potential, were 26 (+/- 6 SD) ng/ml and 289 (+/- 127 SD) ng/g respectively. The efficacy of treatment with 6 mg/kg epidoxorubicin applied intravenously combined with 30 mg kg-1 day-1 dexniguldipine administered orally for 3 days prior to epidoxorubicin injection was evaluated on tumours grown under the renal capsule. Dexniguldipine alone did not show antitumour effects in vivo. Dexniguldipine modestly, but consistently, potentiated the tumour-growth-inhibiting effect of epidoxorubicin, reaching statistical significance in two out of four experiments. In conclusion, these experiments show that dexniguldipine has potency as an MDR reverter in vitro and in vivo in this solid MDR tumour model.