Biomedical subjects

S Rodenhuis

Publications and source records attributed to S Rodenhuis.

At least 55 records · Page 3Linked to original sources

PubMed1999

Management of intermediate-prognosis germ-cell cancer: results of a phase I/II study of Taxol-BEP.

The standard chemotherapy regimen in metastatic germ-cell cancer is bleomycin, etoposide and cisplatin (BEP). Chemotherapy studies testing cisplatin dosage and the substitution of ifosfamide for bleomycin have not shown this to be superior to BEP. Paclitaxel (Taxol) has demonstrated promising activity as a second-line treatment in patients with relapsing or cisplatin-refractory germ-cell cancer. Hence, the potential of incorporating paclitaxel in first-line chemotherapy should be investigated. We assessed the feasibility of the addition of paclitaxel to BEP (T-BEP) in a phase I/II study in patients with intermediate- or poor-prognosis germ-cell cancer or with carcinoma of unknown primary (CUP). Paclitaxel was investigated at dose levels of 75, 125, 175 and 200 mg/m2 given as a 3 hr infusion on day 1, before the start of BEP. BEP comprised etoposide at a dose of either 120 mg/m2 on days 1, 3 and 5 or 100 mg/m2 on days 1-5. To deliver the highest possible dose of paclitaxel into BEP, all patients received filgrastim (G-CSF). Thirty patients were entered, 14 of whom had intermediate- (n = 7) or poor- (n = 7) prognosis germ-cell cancer. Paclitaxel up to 200 mg/m2 and BEP at 360 mg/m2 was well tolerated. There was minimal neurosensory and no neuromotor toxicity with the use of 4 T-BEP cycles. More pronounced myelotoxicity and diarrhea at the higher dose level of etoposide resulted in a recommended dose level for multicenter phase II/III testing of paclitaxel 175 mg/m2 and BEP 500 mg/m2. Of the 13 evaluable patients with intermediate- or poor-prognosis germ-cell cancer, all achieved complete response. With a median follow-up of 18 months, none of these patients has relapsed. We conclude that T-BEP is a well-tolerated induction regimen that should be further tested for its therapeutic potential. A randomized phase II/III study of T-BEP vs. BEP has been started as an EORTC trial in patients with intermediate-prognosis disease.

Adolescent↗

PubMed1999

A search for new metabolites of N,N',N''-triethylenethiophosphoramide.

An attempt was made to unravel the metabolic profile of the alkylating agent N,N',N''-triethylenethiophosphoramide (thioTEPA). thioTEPA and its metabolite N,N',N-triethylenephosphoramide (TEPA) were quantified in urine of treated patients by gas chromatography with selective nitrogen/phosphorous detection. Total alkylating activity was assessed by p-nitrobenzylpyridine reactivity. The total alkylating activity exceeded the amount of thioTEPA and TEPA, indicating the presence of other alkylating metabolites. Solid-phase extraction and liquid-liquid extractions followed by gas chromatography-mass spectrometry analysis revealed the conversion of an aziridinyl function of TEPA into a beta-chloroethyl moiety. This metabolite, N,N'-diethylene-N''-2-chloroethylphosphoramide, was quantified by gas chromatography with selective nitrogen/phosphorous detection and accounted for only 0.69% of the administered dose. Large volumes of urine were concentrated with solid-phase extraction and fractionated with high-performance liquid chromatography. Alkylating activity was determined for each 2-ml fraction and showed the presence of an alkylating compound eluting between 8 and 12 ml. The fractions with alkylating activity were collected, evaporated under a stream of nitrogen at room temperature to dryness, reconstituted in methanol, and subjected to fast atom bombardment-mass spectrometry and fast atom bombardment-tandem mass spectrometry. A new metabolite was found with a molecular mass of 352 Da, the same as that of thioTEPA-mercapturate. thioTEPA-mercapturate is likely the result of glutathione conjugation, after which the glutathione adduct loses two amino acid residues in separate stages. The fragmentation pattern and chromatographic properties of this new metabolite were identical to those of the reference, thioTEPA-mercapturate, which was obtained by incubation of thioTEPA with N-acetylcysteine at pH 11 and 95 degrees C for 30 min. Quantification of thioTEPA-mercapturate was carried out by liquid chromatography-mass spectrometry. The thioTEPA-mercapturate levels in urine accounted for 12.3% of the administered dose and exceeded the amount of TEPA, which was previously assumed to be the main metabolite of thioTEPA. The total excreted amount of thioTEPA and its metabolites accounts for 54-100% of the total alkylating activity, indicating the presence of still other alkylating metabolites.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

[High-dose chemotherapy with stem cell support for solid tumors in adults].

High-dose chemotherapy for advanced solid malignancies has been the subject of many clinical studies. The replacement of autologous bone marrow transplantation by peripheral blood haematopoietic progenitor cell transplantation and other advances in supportive care have led to a considerable reduction of therapy-related mortality and morbidity. In certain rare disorders, such as germ cell tumours or pediatric sarcomas in adults, high-dose therapy is currently considered the therapeutic standard. It is likely that a subgroup of patients with high-risk or disseminated breast cancer can also benefit in terms of survival from this treatment modality, but final proof from randomized studies remains to be generated. On theoretical grounds, high-dose chemotherapy could also be effective in small cell lung cancer and ovarian cancer, and randomized studies to answer this question are in progress. Many investigators concur that high-dose chemotherapy often leads to dramatic cytoreduction in solid tumours, but only rarely achieves cure. Novel therapeutic modalities are required to control the residual microscopic disease.

Adult↗

PubMed1999

A single 24-hour plasma sample does not predict the carboplatin AUC from carboplatin-paclitaxel combinations or from a high-dose carboplatin-thiotepa-cyclophosphamide regimen.

PURPOSE: It has been observed that the area under the free carboplatin concentration in plasma ultrafiltrate versus time curve (AUC) is related to toxicity and tumour response. For this reason, it can be important to measure the carboplatin AUC and subsequently adjust the dose to achieve a predefined target AUC. The use of limited sampling strategies enables relatively simple measurement and calculation of actual carboplatin AUCs. METHODS: We studied the performance of a limited sampling model, based on a single 24-h sample (the Ghazal-Aswad model). in 52 patients who received carboplatin in two different chemotherapy regimens (a carboplatin-paclitaxel combination and a high-dose carboplatin-thiotepa-cyclophosphamide combination). RESULTS: The measured mean AUC in our population was 4.1 min x mg/ml (median 3.9, range 1.9 6.3, SD 1.0 min x mg/ml). With the limited sampling model, the predicted mean AUC was 4.4 min x mg/ml (median 4.2, range 2.4-8.4, SD 1.2 min x mg/ml). Statistical analysis revealed that the model was slightly biased (MPE%, 6.5%), but imprecise (RMSE%, 20.6%) in our study population. CONCLUSION: Although easy and attractive to use, the Ghazal-Aswad formula is not precise enough to predict the carboplatin AUC, and needs to be evaluated prospectively in other patient populations.

Adolescent↗

PubMed1999

Dose-intensive chemotherapy for locally advanced breast cancer.

The availability of hematopoietic growth factors has allowed a range of feasibility and uncontrolled studies with high-dose chemotherapy (with or without stem-cell support) to take place. Preliminary data from some randomized studies are now available as well. Dose-intensive chemotherapy appears to be effective in downstaging the tumor. Only a minority of patients achieve a pathologic complete remission and additional therapeutic options to control minimal residual disease are urgently needed. There are few indications that high-dose chemotherapy is superior to conventional dose therapy in terms of relapse-free or overall survival. Although the results of most randomized studies are premature or unknown at this time, a modest but clinically significant survival advantage may still emerge.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

Temozolomide in adult patients with advanced soft tissue sarcoma: a phase II study of the EORTC Soft Tissue and Bone Sarcoma Group.

Temozolomide, an oral imidazotetrazine derivative, was given to 31 patients with advanced soft tissue sarcoma. The dose of 750 mg/m2 was divided over 5 consecutive days, and escalated to 1000 mg/m2 over 5 days at cycle 2 if myelosuppression no worse than common toxicity criteria grade 2 was noted in the first 28-day cycle. A total of 99 treatment cycles were given to 31 patients. The drug was well tolerated, with nausea and vomiting as the most common side-effects. Only one partial tumour response was documented, giving a response rate of 3.33%, 95% confidence interval, (CI) 0.1-17.2%. The median time to progression was 8 weeks and the median survival was 27 weeks. These results indicate that temozolomide in this schedule is not active as second-line treatment in advanced soft tissue sarcoma.

Adult↗

PubMed1999

Comparison of immunocytochemistry, reverse transcriptase polymerase chain reaction, and nucleic acid sequence-based amplification for the detection of circulating breast cancer cells.

Detection of tumor cells in blood and bone marrow is increasingly used for the staging of patients with breast cancer and to evaluate the presence of tumor cells in peripheral blood progenitor cell collections to be used after high-dose therapy. We evaluated the sensitivity and specificity of three different methods for detection of tumor cells among non-tumor tissue. An immunocytochemical assay using antibodies directed against epitopes of the cytokeratin-19 (CK19) protein and two RNA-based methods: reverse transcriptase polymerase chain reaction (RT-PCR) and Nucleic Acid Sequence-Based Amplification (NASBA) for the same target gene were tested. With all the three methods, false-positive results were observed when peripheral blood mononuclear cells (PBMC) of healthy volunteers were tested. There was no concordance between the RNA-based assays and the immunocytochemical assay. The false-positive results in the RNA-based assays may be due to 'illegitimate expression' of epithelial genes in normal PBMC. The false-positive results in the immunocytochemical assay resulted from background staining of monocytes and granulocytes. This study demonstrates that CK19 is not a suitable target to detect the presence of breast tumor tells in PBMC. To reliably detect circulating tumor cells with RNA methods, the selection of suitable target genes is required, which are highly expressed in tumors but not at all in normal cells of blood and bone marrow. Genes with such characteristics may be identifiable with novel differential display techniques.

Breast Neoplasms↗

PubMed1999

A multi-center prospective phase II study of high-dose chemotherapy in germ-cell cancer patients relapsing from complete remission.

PURPOSE: To prospectively determine the efficacy of repeated high-dose alkylating chemotherapy to salvage patients with germ-cell tumors who relapsed after adequate first-line chemotherapy. PATIENTS AND METHODS: Patients with germ-cell cancers relapsing from a first, second or third complete remission induced by chemotherapy were offered to participate in a Dutch national prospective trial with broad entry criteria. The salvage treatment began with a conventional dose of ifosfamide (4 g/m2 on day 1) and etoposide (100 mg/m2 on days 1, 2 and 3) followed by daily s.c. administration of G-CSF (10 micrograms/kg) until peripheral blood progenitor cells had been harvested. Immediately after bone marrow recovery, an intermediate dose chemotherapy course of carboplatin (target AUC: 10 mg.ml-1 min on day 1) and etoposide (500 mg/m2 on days 1, 3 and 5) was given with G-CSF daily s.c. After bone marrow recovery, two subsequent courses of high-dose 'CTC' chemotherapy were given, each containing cyclophosphamide (6 g/m2), thiotepa (480 mg/m2) and carboplatin (target AUC: 20 mg.ml-1 min). The high-dose chemotherapy was administered as 30-60-minute infusions, divided over 4 days and the stem-cell transplants were given 48-72 hours after the last chemotherapy infusion. Whenever possible, residual masses were resected at the end of treatment. RESULTS: Thirty-five patients were treated between January 1994 and October 1997. The toxicity of the treatment was manageable. Second CTC courses were administered in 25 patients and were associated with hemorrhagic cystitis and veno-occlusive disease in 3 and 4 patients, respectively. One patient who had recently undergone a partial hepatectomy, died of veno-occlusive disease. At the time of analysis, the median follow-up of the surviving patients was 37 months (range 12-56 months). The median progression-free survival for all patients was 44 months, and the median overall survival has not been reached. According to the internationally accepted criteria for predicting the outcome of salvage chemotherapy in germ-cell cancer (Beyer et al. J Clin Oncol 1996; 14: 2638-45), 30 patients had 'good risk' criteria. Of these, 29 received high-dose chemotherapy. Of this group, the salvage rate at two years was 65% (95% confidence interval: 49.5%-85.1%). CONCLUSIONS: Over half of the germ-cell cancer patients relapsing from a chemotherapy-induced complete remission can be salvaged by a treatment strategy that incorporates high-dose chemotherapy, even when treatment is given in a multi-center setting. These data confirm the international prognostic model proposed by Beyer et al. in a prospectively studied, independent patient group and provide further evidence that high-dose therapy has a role in the salvage setting of patients with germ-cell cancer.

Adult↗

PubMed1999

At home management of aplastic phase following high-dose chemotherapy with stem-cell rescue for hematological and non-hematological malignancies.

BACKGROUND: After high-dose chemotherapy with autologous stem-cell support long hospital stays in the aplastic phase are expensive, lead to increased risk of hospital infections and to increasing pressure on available hospital beds. We developed a home care regimen that allows patients to be at home for most of the aplastic period, without daily hospital visits. PATIENTS AND METHODS: Between October 1995 and December 1997, transfer of supportive care to the home setting took place in three phases for patients undergoing high-dose chemotherapy with stem-cell transplant for malignant lymphoma (one course of BEAM), breast cancer or germ-cell cancer (three courses of tCTC). In the inpatient cohort, the supportive care designed for at home use was administered in the hospital until neutrophile recovery to 0.5 x 10(9)/l. In the second, outpatient cohort, patients were discharged the day after stem-cell reinfusion but the supportive care was delivered daily in hospital. The third, home care cohort, consisted of patients who were discharged the day after stemcell reinfusion, after which specialized home care professionals delivered all supportive care including transfusions and parenteral antibiotics at home, with once weekly check-up in hospital by the transplant physician. RESULTS: Forty-two patients were treated with 81 cycles of high-dose chemotherapy (11, 18 and 13 patients and 17, 40 and 24 courses in the inpatient, outpatient and home care cohorts respectively). Inpatients were hospitalized in the aplastic phase for a median of 14 days. Patients in the outpatient cohort were at home in the aplastic phase for a median of six days (with a median of six days in hospital), and in the home care cohort for a median of 10 days (with a median of 1.5 days in hospital). Unscheduled readmissions and hospital visits were frequent in the outpatient and home care cohorts, mostly due to fever, central indwelling catheter malfunctioning or chemotherapy-related toxicity. However, patients could usually be discharged again after observation and treatment. No infectious deaths or unexpected emergencies occurred in the outpatient or home care cohort. Neither was there any suggestion of an increased number of fevers, infections, or other complications. CONCLUSIONS: At home management in the aplastic phase after high-dose chemotherapy and stemcell transplant by community-based professionals is feasible without signs of increased toxicity or infections.

Adult↗

PubMed1999

Topoisomerase I/II inhibitor intoplicine administered as a 24 h infusion: phase I and pharmacologic study.

Intoplicine, an antitumor drug which interacts with both topoisomerase enzymes I and II, has demonstrated a broad spectrum of activity in preclinical studies. This indicates further clinical evaluation. In the present phase I study, with the primary objective to determine the maximum tolerated dose, intoplicine was administered by a 24 h continuous infusion every 21 days to 32 patients with solid malignant tumors. The patients received 12-640 mg/m2 by a central venous catheter. Liver toxicity was dose limiting. One patient died in a hepatic coma after the first course (dose 640 mg/m2), which was associated with intoplicine treatment. Other side effects were sporadic and mild. Myelotoxicity was virtually absent. Twenty-two patients had stable disease for four to six courses of treatment. The plasma concentration-time curves were compatible with standard linear pharmacokinetic models, with a protracted terminal half-life (mean 115 h). Although one sudden death occurred probably due to intoplicine toxicity, we nevertheless feel that research with intoplicine should continue, mainly because of its preclinical activity and its unique mechanism of action. The recommended dose for phase II studies with intoplicine administered as a 24 h infusion is 384 mg/m2. Liver toxicity, also seen in studies employing other dosages and infusion durations, should be investigated extensively in further clinical studies.

Adult↗

PubMed1999

Phase II study of raltitrexed ('Tomudex') for patients with advanced soft tissue sarcomas refractory to doxorubicin-containing regimens.

Advanced soft tissue sarcomas (ASTS) refractory to therapy with doxorubicin and/or ifosfamide are highly resistant to therapy with other cytotoxic agents. The efficacy and safety of raltitrexed ('Tomudex') was assessed in patients with ASTS refractory to one or two doxorubicin- and/or ifosfamide-containing regimens in eight centers of the EORTC STBSG group. Raltitrexed was given at 3 mg/m2 as a 15 min i.v. infusion once every 3 weeks. Among the 23 patients [mean age 54 (range 25-73) years] included, 22 patients (15 males and seven females) were eligible and evaluable for response to therapy and 21 were evaluable for toxicity. Patients had previously received chemotherapy in metastatic phase (n=16), as adjuvant treatment (n=5) or both (n=1). The primary tumor was located in the trunk (n=11), in the limbs (n=8) or in the head and neck (n=3). Most patients (n=13) received two courses of raltitrexed (range 1-8). The best response was stable disease in five (23%) patients, while disease progression was noted in 17 patients (77%); the median time to disease progression was 6 weeks. The treatment was well tolerated with only one patient experiencing grade 4 neutropenia and thrombocytopenia, one patient experiencing grade 3 nausea, one lethargy, one headache, and one asthenia. Only one patient experienced febrile neutropenia. Raltitrexed as monotherapy is not an effective treatment for patients with ASTS who failed conventional chemotherapy with doxorubicin and ifosfamide.

Adult↗

PubMed1999

Sampling technique from central venous catheters proves critical for pharmacokinetic studies.

Double-lumen central venous access (CVA) catheters are occasionally used in pharmacokinetic studies for drug administration and blood sampling. The samples are often collected by the nursing staff and thus the investigator may not be aware of the specific sampling technique used. We present an example of the dramatic effect that an incorrect sampling technique from double-lumen CVA catheters can have on pharmacokinetic outcomes. Using a double-lumen Hickman catheter (PolyCath Central Venous Catheter; Strato Medical Corporation/Infusaid Inc., Manchester, GA, U.S.A.), sampling during the infusion can be performed when the infusion is connected to the lumen with the end most downstream and blood is collected from the proximal opening. With a normal double-lumen catheter, sampling can only be performed by briefly interrupting the infusion or after the infusion.

Catheterization, Central Venous↗

PubMed1998

Determination of N,N',N"-triethylenethiophosphoramide and its active metabolite N,N',N"-triethylenephosphoramide in plasma and urine using capillary gas chromatography.

A sensitive assay for the determination of N,N',N"-triethylenethiophosphoramide (thioTEPA) and its metabolite N,N',N"-triethylenephosphoramide (TEPA) in micro-volumes human plasma and urine has been developed. ThioTEPA and TEPA were analysed using gas chromatography with selective nitrogen-phosphorus detection or mass spectrometry after extraction with a mixture of 1-propanol-chloroform from the biological matrix. Diphenylamine was used as internal standard. The limit of detection was 1.5 ng/ml for thioTEPA and 2.5 ng/ml for TEPA, using 100 microl of biological sample; recoveries ranged between 70 and 90% and both accuracy and precision were less than 10%. Linearity was accomplished in the range of 10-1000 ng/ml for plasma and 100-10000 ng/ml for urine using thermionic nitrogen-phosphorus detection. With mass spectrometry a linear range of 100-25000 ng/ml TEPA in plasma or urine was obtained. For thioTEPA a second-order polynomial function describes the relationship between the analyte concentration in the range of 500-25000 ng/ml and detection response. TEPA proved to be stable in plasma and urine for at least 10 weeks at -80 degrees C. ThioTEPA and TEPA plasma concentrations of two patients treated with thioTEPA are presented demonstrating the applicability of the assay for clinical samples.

Chromatography, Gas↗

PubMed1998

Simultaneous determination of N,N',N"-triethylenethiophosphoramide, cyclophosphamide and some of their metabolites in plasma using capillary gas chromatography.

A sensitive assay for the simultaneous determination of N,N',N"-triethylenethiophosphoramide (thioTEPA), its metabolite N,N',N"-triethylenephosphoramide (TEPA), cyclophosphamide (CP) and its metabolite 2-dechloroethylcyclophosphamide (2-DCE-CP) in plasma has been developed and validated. The analytes were determined using gas chromatography with nitrogen/phosphorus selective detection after liquid-liquid extraction with chloroform using 100 microl of plasma. Diphenylamine (for TEPA, thioTEPA and 2-DCE-CP) and imipramine (for CP) were used as internal standards. The limits of quantitation for thioTEPA, TEPA, CP and 2-DCE-CP were 5, 5, 50 and 250 ng/ml, respectively. Linear calibration curves were observed over two decades of concentration. Accuracy, within-day and between-day precision were less than 13% for all analytes. Stability of the analytes proved to be satisfactory for at least 1 month, stored at -70 degrees C. Analysis of samples obtained from patients receiving cyclophosphamide, thioTEPA and carboplatin in a high-dose regimen demonstrated the applicability of the assay.

Antineoplastic Agents, Alkylating↗

PubMed1998

Randomised trial of high-dose chemotherapy and haemopoietic progenitor-cell support in operable breast cancer with extensive axillary lymph-node involvement.

BACKGROUND: Uncontrolled studies suggest that high-dose chemotherapy is beneficial in patients with breast cancer and multiple metastases to the axillary lymph nodes. Many physicians accept this treatment as standard care. We aimed to assess adjuvant high-dose chemotherapy in breast cancer in a phase II randomised trial. METHODS: 97 women aged younger than 60 years, who had breast cancer with extensive axillary-node metastases (confirmed by a tumour-positive infraclavicular lymph-node biopsy), received three courses of up-front chemotherapy (FE120C). This regimen consisted of cyclophosphamide 500 mg/m2, epirubicin 120 mg/m2, and 5-fluorouracil 500 mg/m2 once weekly for 3 weeks. After surgery, stable patients or those who responded to chemotherapy were randomly assigned conventional therapy (fourth course of FE120C, followed by radiation therapy and 2 years of tamoxifen [40 patients]) or high-dose therapy (identical treatment but an additional high-dose regimen and peripheral-blood progenitor-cell [PBPC] support after the fourth FE120C course [41 patients]). This high-dose regimen comprised cyclophosphamide 6 g/m2, thiotepa 480 mg/m2, and carboplatin 1600 mg/m2. The primary endpoint was overall and disease-free survival. All analyses were by intention to treat. FINDINGS: No patients died from toxic effects of chemotherapy. With a median follow-up of 49 (range 21-76) months, the 4-year overall and relapse-free survivals for all 97 patients were 75% and 54%, respectively. There was no significant difference in survival between the patients on conventional therapy and those on high-dose therapy. INTERPRETATION: High-dose therapy is associated with substantial cost and acute toxic effects, but also has potentially irreversible long-term effects. Until the benefit of this therapy is substantiated by large-scale phase III trials, high-dose chemotherapy should not be used in the adjuvant treatment of breast cancer, apart from in randomised studies.

Antibiotics, Antineoplastic↗

PubMed1998

Impairment of cognitive function in women receiving adjuvant treatment for high-risk breast cancer: high-dose versus standard-dose chemotherapy.

BACKGROUND: Although high-dose chemotherapy is rapidly gaining acceptance as a treatment option for a number of cancers, the long-term toxic effects of such therapy are a concern. Cognitive deficits (e.g., problems with memory and concentration) are not uncommon after chemotherapy, but they have not been documented systematically. In this study, we assessed the prevalence of cognitive deficits in a group of patients with high-risk breast cancer who were randomly assigned to receive either high-dose or standard-dose adjuvant chemotherapy plus tamoxifen, and we investigated whether high-dose chemotherapy impaired cognitive functioning more than standard-dose chemotherapy. METHODS: Cognitive functioning was evaluated by use of a battery of neuropsychologic tests. In addition, patients were interviewed with regard to cognitive problems, health-related quality of life, anxiety, and depression. Results from patients who received adjuvant systemic therapy were compared with results from patients who had early stage breast cancer not treated with such therapy (control patients). RESULTS: The study population consisted of 34 patients treated with high-dose chemotherapy plus tamoxifen, 36 patients treated with standard-dose chemotherapy plus tamoxifen, and 34 control patients. For all patients, the average time since the completion of last nonhormonal therapy was 2 years. Cognitive impairment was found in 32% of the patients treated with high-dose chemotherapy, in 17% of the patients treated with standard-dose chemotherapy, and in 9% of the control patients. In comparison with the control patients, patients treated with high-dose chemotherapy appeared to have an 8.2-times higher risk of cognitive impairment (odds ratio; 95% confidence interval [CI] = 1.8-37.7); in comparison with the patients who received standard-dose chemotherapy, this risk of impairment was 3.5-times higher (95% CI = 1.0-12.8). CONCLUSION: High-dose chemotherapy appears to impair cognitive functioning more than standard-dose chemotherapy. Central nervous system toxicity may be a dose-limiting factor in high-dose chemotherapy regimens.

Adult↗

PubMed1998

Malignant effusions contain lysophosphatidic acid (LPA)-like activity.

BACKGROUND: Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are bioactive phospholipids with mitogenic and growth factor-like activities that act via specific cell-surface receptors present in many normal and transformed cell types. LPA has recently been implicated as a growth factor present in ascites of ovarian cancer patients. The presence of LPA-like activity and the hypothesis that levels of this bioactivity in effusions of ovarian cancer patients are higher than those in effusions of other cancer patients was studied. MATERIALS AND METHODS: A neurite retraction bioassay in a neuroblastoma cell line previously developed for in vitro detection of LPA activity on cell lines was employed and bioactivity was expressed in virtual LPA-equivalent levels. LPA-equivalent levels were tested in effusions of 62 patients with a range of malignancies, including 13 ovarian cancer patients. Biochemical and clinical parameters were evaluated for correlations with LPA-equivalent levels. RESULTS: Average LPA-equivalent levels were 50.2 microns (range 5.4-200) for all patients, and 94.5 microns (range 15-200) for ovarian cancer patients (P = 0.004). There were no additional independent significant correlations between LPA-equivalent levels in effusions and a range of other biochemical and clinical characteristics. CONCLUSION: These data suggest a role for LPA-like lipids in the peritoneal spread of ovarian cancer and possibly that of other predominantly intraperitoneal malignancies.

Adenocarcinoma↗

PubMed1998

The detection of minimal numbers of contaminating epithelial tumor cells in blood or bone marrow: use, limitations and future of RNA-based methods.

BACKGROUND: Many solid tumors commonly metastasize to the bone marrow and the presence of tumor cells in the bone marrow is associated with a poor prognosis. Detection of tumor cells in the bone marrow has been reported to be important to determine the prognosis of newly diagnosed patients and may be helpful in deciding whether or not systemic treatment is indicated. PATIENTS AND METHODS: The majority of the studies focus on the detection of tumor cells in non-tumor tissue using immunocytochemistry and antibodies directed against epitopes of epithelial genes. Recently, the sensitive reverse-transcriptase polymerase chain reaction (RT-PCR) has been employed for the detection of tumor cells in bone marrow, using mRNA transcribed from epithelial genes as targets for RT-PCR. RESULTS: In some studies, encouraging results were reported when RT-PCR was used to detect expression of epithelial genes, but in many others frequent false-positive results were observed. These may results from the 'illegitimate expression' of epithelial genes in cells of non-epithelial tissues, such as bone marrow. CONCLUSIONS: Micrometastases in bone marrow can be detected with some sensitivity by antibodies directed against epithelial genes. RNA based methods, using epithelial genes as target for amplification, are less reliable. To improve these methods, a systematic approach is required to identify genes which are highly expressed in solid tumors and completely silent in blood and bone marrow of healthy individuals. Novel techniques, e.g., 'sequential analysis of gene expression (SAGE), are now available that allow such an endeavor.

Biomarkers, Tumor↗