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L Edler

Publications and source records attributed to L Edler.

At least 19 recordsLinked to original sources
PubMed2006

Risk assessment of substances that are both genotoxic and carcinogenic report of an International Conference organized by EFSA and WHO with support of ILSI Europe.

The European Food Safety Authority (EFSA) and the World Health Organization (WHO), with the support of the International Life Sciences Institute, European Branch (ILSI Europe), organized an international conference on 16-18 November 2005 to discuss how regulatory and advisory bodies evaluate the potential risks of the presence in food of substances that are both genotoxic and carcinogenic. The objectives of the conference were to discuss the possible approaches for risk assessment of such substances, how the approaches may be interpreted and whether they meet the needs of risk managers. ALARA (as low as reasonably achievable) provides advice based solely on hazard identification and does not take into account either potency or human exposure. The use of quantitative low-dose extrapolation of dose-response data from an animal bioassay raises numerous scientific uncertainties related to the selection of mathematical models and extrapolation down to levels of human exposure. There was consensus that the margin of exposure (MOE) was the preferred approach because it is based on the available animal dose-response data, without extrapolation, and on human exposures. The MOE can be used for prioritisation of risk management actions but the conference recognised that it is difficult to interpret it in terms of health risk.

Animals↗
PubMed2006

Corticosteroid-induced chemotherapy resistance in urological cancers.

PURPOSE: Glucocorticoids such as dexamethasone are widely used for medication of urological diseases, e.g., as cotreatment of advanced prostate cancer, to improve appetite, weight loss, fatigue, relieve bone pain, diminish ureteric obstruction, to reduce the production of adrenal androgens, as an antiemetic in patients undergoing chemo- and/or radiotherapy together with serving as "standard" therapy arm in randomized studies. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumor therapy in lymphoid cells are well studied, the impact to growth of prostate and other urological carcinomas is unknown. METHODS: We isolated cells from surgical resections of 21 prostate tumors and measured apoptosis and viability in these primary cells and 17 established cell lines from human prostate, bladder, renal cell and testicular carcinomas. RESULTS: We found that dexamethasone induces resistance regarding exposure to several cytotoxic agents such as taxol, gemcitabine, cisplatin, 5-FU and gamma-irradiation in 86% of the freshly isolated prostate tumors and in 100% of the established urological cell lines. No difference in dexamethasone-mediated protection was found in normal, benign and malignant prostate tumors. CONCLUSIONS: These data show for the first time that dexamethasone induced therapy resistance in urological carcinomas is not the exception but a more common phenomenon and implicate that glucocorticoids may have two faces in cancer therapy, a beneficial and a dangerous one.

Adrenal Cortex Hormones↗
PubMed2006

Dacarbazine (DTIC) versus vaccination with autologous peptide-pulsed dendritic cells (DC) in first-line treatment of patients with metastatic melanoma: a randomized phase III trial of the DC study group of the DeCOG.

BACKGROUND: This randomized phase III trial was designed to demonstrate the superiority of autologous peptide-loaded dendritic cell (DC) vaccination over standard dacarbazine (DTIC) chemotherapy in stage IV melanoma patients. PATIENTS AND METHODS: DTIC 850 mg/m2 intravenously was applied in 4-week intervals. DC vaccines loaded with MHC class I and II-restricted peptides were applied subcutaneously at 2-week intervals for the first five vaccinations and every 4 weeks thereafter. The primary study end point was objective response (OR); secondary end points were toxicity, overall (OS) and progression-free survival (PFS). RESULTS: At the time of the first interim analysis 55 patients had been enrolled into the DTIC and 53 into the DC-arm (ITT). OR was low (DTIC: 5.5%, DC: 3.8%), but not significantly different in the two arms. The Data Safety & Monitoring Board recommended closure of the study. Unscheduled subset analyses revealed that patients with normal serum LDH and/or stage M1a/b survived longer in both arms than those with elevated serum LDH and/or stage M1c. Only in the DC-arm did those patients with (i) an initial unimpaired general health status (Karnofsky = 100) or (ii) an HLA-A2+/HLA-B44- haplotype survive significantly longer than patients with a Karnofsky index <100 (P = 0.007 versus P = 0.057 in the DTIC-arm) or other HLA haplotypes (P = 0.04 versus P = 0.57 in DTIC-treated patients). CONCLUSIONS: DC vaccination could not be demonstrated to be more effective than DTIC chemotherapy in stage IV melanoma patients. The observed association of overall performance status and HLA haplotype with overall survival for patients treated by DC vaccination should be tested in future trials employing DC vaccines.

Cancer Vaccines↗
PubMed2005

Dexamethasone desensitizes hepatocellular and colorectal tumours toward cytotoxic therapy.

The glucocorticoid dexamethasone is frequently used as co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact to cytotoxic treatment of colorectal and hepatocellular carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using 8 established cell lines, 18 surgical specimen and a xenograft on nude mice. In the presence of dexamethasone we found strong inhibition of apoptosis in response to 5-FU, cisplatin, gemcitabine or gamma-irradiation, enhanced viability and tumour growth of colorectal and hepatocellular carcinomas. No correlation with age, gender, histology, TNM, the p53 status and induction of therapy resistance by dexamethasone co-treatment could be detected. These data show that glucocorticoid-induced resistance occurs not occasionally but is common in colorectal and hepatocellular carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients.

Animals↗
PubMed2005

Adjuvant therapy with edrecolomab versus observation in stage II colon cancer: a multicenter randomized phase III study.

BACKGROUND: In a phase III study recruiting patients with stage II colon cancer the effect of adjuvant therapy with edrecolomab, a murine monoclonal antibody to the cell-surface glycoprotein 17-1A, was compared to observation alone. PATIENTS AND METHODS: From January 1997 until July 2000 a total of 377 patients were postoperatively stratified according to tumor stage (T3 vs. T4) and center, and randomly allocated to either treatment with edrecolomab (cohort A, n = 183) or observation (cohort B, n = 194). Patients in cohort A received a total of 900 mg edrecolomab. The study was terminated prematurely because of discontinuation of drug supply in Germany. RESULTS: 305 patients were eligible for the primary endpoint of overall survival and 282 patients for disease-free survival. After a median follow-up of 42 months overall survival and disease-free survival were not significantly different. Toxicity was mild. CONCLUSIONS: In the present study, postoperative adjuvant treatment with edrecolomab in patients with resected stage II colon cancer did not improve overall or disease-free survival.

Adult↗
PubMed2004

Randomized phase III study of gemcitabine and vinorelbine versus gemcitabine, vinorelbine, and cisplatin in the treatment of advanced non-small-cell lung cancer: from the German and Swiss Lung Cancer Study Group.

PURPOSE: To evaluate whether cisplatin-based chemotherapy (gemcitabine, vinorelbine, and cisplatin [GVP]) prolongs overall survival in comparison to cisplatin-free chemotherapy (gemcitabine and vinorelbine [GV]) as first-line treatment in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Between September 1999 and June 2001, 300 patients with NSCLC stage IIIB with malignant pleural effusion or stage IV disease were randomly assigned to receive GV (gemcitabine 1000 mg/m(2) + vinorelbine 25 mg/m(2) on days 1 and 8 every 3 weeks) or GVP (gemcitabine 1000 mg/m(2) + vinorelbine 25 mg/m(2) on days 1 and 8 + cisplatin 75 mg/m(2) on day 2 every 3 weeks). Primary end point of the study was overall survival. RESULTS: Two hundred eighty-seven patients (GV, 143 patients; GVP, 144 patients) were eligible for analysis. At the time of analysis, April 15, 2002, 209 patients (GV, 103 patients; GVP, 106 patients) of 287 patients had died (73%). No statistically significant difference was observed for overall survival (P =.73; median survival, 35.9 versus 32.4 weeks; 1-year survival rate, 33.6% versus 27.5%) as well as for event-free survival (P =.35; median time-to-event, 19.3 versus 22.3 weeks) between GV and GVP. Two hundred fourteen patients were assessable for best response. The overall response rates were 13.0% for GV versus 28.3% for GVP (P =.004; complete responders, 0% versus 3.8%; partial responders, 13.0% versus 24.5%). Hematologic and nonhematologic toxicity was significantly lower in the GV treatment arm compared with GVP. No statistically significant difference in quality of life was observed. CONCLUSION: In this phase III study, the cisplatin-based GVP regimen showed no survival benefit as first-line chemotherapy in advanced NSCLC when compared with the cisplatin-free GV regimen, which was substantially better tolerated.

Adolescent↗
PubMed2003

Randomized clinical trial: myths around elementary statistical principles.

In discussing design and results of randomized clinical trials, in particular with clinical oncologists, one often encounters the opinion that a phase III trial is a complicated, highly costly, and difficult task. Part of this opinion seems to originate in myths around underlying biostatistical principles such as randomization, sampling and sample size, statistical hypotheses, statistical error probabilities, and statistical power. This work clarifies basic statistical issues of randomized clinical trials and the interpretation of their results. Six issues ('myths') relevant for the design of clinical trials and the interpretation of their results are addressed. They concern choice of study design, choice of participating centers, and recruitment of patients as well as statistical questions of establishing study hypotheses and interpreting p values. These myths are shown to be caused primarily through a misunderstanding of statistical inference and statistical thinking that can be avoided when a rational understanding of statistical principles is translated into a clinical research approach. We also conclude that before clinical evidence is summarized from different studies each study should be examined thoroughly.

Bias↗
PubMed2003

Evaluation of historical control data in carcinogenicity studies.

Results obtained in long-term carcinogenicity studies with animals should be evaluated, first and foremost, by statistical comparisons of the data obtained from the treated group with that from the concurrent control group. Often the results are compared with data from so-called historical control groups in order to take variations in the incidences of spontaneous tumours into account. Because historical control data change in the course of time and for a variety of reasons, certain requirements must be met before they may be used in the evaluation of the results of long-term studies. The present paper discusses potential sources of variability of tumour incidences in untreated animals, presents databanks for historical control data, mentions the factors that affect tumour incidences in untreated animals and describes biostatistical data evaluation. Finally, details are given of the criteria used by the DFG Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area to decide whether historical control data may be applied. These include the requirement that the historical control data were obtained with animals of the same species and strain and from the same breeder. The data were obtained in the same laboratory, the study design, experimental methods and assessment criteria were the same, and the studies used for the comparison were carried out within a limited time window. Historical control data that have not been published may be used provided they fulfil the above criteria and have been made available in sufficient detail to be comprehensible.

Animals↗
PubMed2002

Gemcitabine, vinorelbine and cisplatin combination chemotherapy in advanced non-small cell lung cancer: a phase II trial.

The purpose of this phase II trial was to investigate the efficacy and safety of a combination chemotherapy with gemcitabine, vinorelbine and cisplatin in the first-line treatment of advanced non-small cell lung cancer (NSCLC). Patients with NSCLC stage IIIB or IV disease received 1000 mg/m(2) gemcitabine and 25 mg/m(2) vinorelbine on days 1 and 8 and 75 mg/m(2) cisplatin on day 2, every 3 weeks. From December 1998 to May 1999, 31 patients (21 stage IV and 10 stage IIIB disease), with a median age of 59 years (range 40-72 years) were enrolled. The overall intent-to-treat response rate was 45% (95% confidence interval (CI): 27-64%) with 2 complete responders (CR) and 12 partial responders (PR), 7 patients had stable disease and 10 progressed. Median survival was 12.8 months (95% CI: 6.5-12.8+ months), median time to progression was 5.1 months (95% CI: 3.5-7.7 months), and the 1-year survival rate was 52.9% (95% CI: 36.7-76.2%). Patients with stage IIIB disease had a significantly longer overall survival than patients with stage IV disease (P=0.05). Transient World Health Organization (WHO) grade IV leucopenia, anaemia and thrombocytopenia occurred in 3 (10%), 2 (6%) and 3 (10%) patients, respectively. The predominant non-haematological toxicities were alopecia and nausea/vomiting. 15 patients (48%) had WHO grade II and III alopecia and 14 patients (45%) nausea/vomiting. The combination of gemcitabine, vinorelbine and cisplatin has demonstrated major antitumour efficacy in advanced NSCLC with a manageable toxicity profile.

Adult↗
PubMed2001

p53 codon 72 polymorphism and various human papillomavirus 16 E6 genotypes are risk factors for cervical cancer development.

Risk factors other than human papillomavirus (HPV) infection per se for cervical cancer development have been investigated recently. It was suggested that HPV 16 E6 variants and the p53 codon 72 arginine polymorphism could be progression markers. Indeed, it has been demonstrated that specific E6 variants and p53 arginine were both enriched in cancer. However, especially with regard to the latter, divergent results have been reported. Our aim was thus to investigate whether p53 arginine is important for cervical carcinogenesis by scaling up samples of the two European cohorts, the initial results of which were reported previously. In addition, we have assessed the occurrence of p53 codon 72 arginine, in combination with specific HPV 16 E6 genotypes. We found p53 arginine to be increased in cancer of both cohorts, consistent with our previous concept. Although specific E6 genotypes increased gradually with the severity of the lesion, p53 arginine was enriched in cancer only. Moreover, the frequency of the arginine allele was similar in groups with different E6 genotypes. It is concluded that p53 arginine is a risk factor for cervical cancer but probably acts independently of E6 variants.

Arginine↗
PubMed2001

Modeling cancer detection: tumor size as a source of information on unobservable stages of carcinogenesis.

This paper is concerned with modern approaches to mechanistic modeling of the process of cancer detection. Measurements of tumor size at diagnosis represent a valuable source of information to enrich statistical inference on the processes underlying tumor latency. One possible way of utilizing this information is to model cancer detection as a quantal response variable. In doing so, one relates the chance of detecting a tumor to its current size. We present various theoretical results emerging from this approach and illustrate their usefulness with numerical examples and analyses of epidemiological data. An alternative approach based on a threshold type mechanism of tumor detection is briefly described.

Computer Simulation↗
PubMed2001

Gemcitabine and vinorelbine as first-line chemotherapy for advanced non-small cell lung cancer: a phase II trial.

The purpose of this phase II study was to investigate the efficacy and safety of gemcitabine plus vinorelbine as first-line chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). Eligibility criteria included cytologically or histologically confirmed NSCLC (stage IIIB or IV), no previous chemotherapy, and bidimensionally measurable disease. Patients received 1000 mg/m(2) gemcitabine and 30 mg/m(2) vinorelbine on days 1, 8 and 15 every 4 weeks up to eight courses. From December 1997 to November 1998, 70 patients (59 stage IV and 11 stage IIIB disease), with a median age of 59 years (range 38-74 years) were enrolled. The intent-to-treat response rate was 41% (95% confidence interval (CI) 30-54%) with 1 complete responder (CR) and 28 partial responders (PRs), 15 patients had stable disease (SD) and 26 progressed (PD). Median survival was 8.3 months (95% CI 6.0-9.9 months), median progression-free survival (PFS) was 4.8 months (95% CI 3.9-5.5 months), and 1-year survival rate was 33.5% (95% CI 24.0-46.8%). Patients received a total of 229 cycles. Haematological and non-haematological toxicities were moderate. Transient World Health Organization (WHO)-grade IV leucopenia and thrombocytopenia occurred in 13 (6%) and two (1%) cycles, respectively. The predominant non-haematological toxicity was local reactions of the veins in 19 (27%) patients (WHO-grade II and III). Neurotoxicity was infrequent, non-cumulative, and reversible. The combination of gemcitabine and vinorelbine has demonstrated activity in metastatic NSCLC, with response and survival rates similar to those of cisplatin-based regimens and a more favourable toxicity profile that is well tolerated in an outpatient setting.

Adult↗
PubMed2001

DNA of adeno-associated virus (AAV) in testicular tissue and in abnormal semen samples.

BACKGROUND: Human genital tissues, including spermatozoa, have been found to be frequently infected with the helper-virus dependent parvovirus, adeno-associated virus (AAV). METHODS: To assess the role of AAV infection in disorders of the male reproductive system, semen samples from 95 men (including 73 men attending a fertility programme) and testicular samples from patients with azoospermia (n = 38) or prostate cancer (n = 8) were analysed using polymerase chain reaction for the presence of AAV DNA. Semen quality was assessed according to World Health Organization guidelines and the grade of atrophy of testicular biopsies was determined histomorphologically. RESULTS: AAV DNA was detected in 38% (28/73) of ejaculates from men with abnormal semen analyses (oligoasthenozoospermia or asthenozoospermia) and in 4.6% of normal semen samples (1/22, P = 0.003). DNA from AAV helper-viruses (human papillomaviruses, cytomegalovirus) was detected at similar frequencies in normal and abnormal semen samples. In testes, AAV DNA was detected in 10 out of 38 biopsies from infertile men (26%), and in 2 out of 8 orchidectomy samples. CONCLUSION: The data show an increased incidence of AAV infection with abnormal semen analysis. Detection of AAV DNA in the testes might point to a role for AAV infection in male infertility, possibly by interfering with spermatozoa development.

Adolescent↗
PubMed2001

Relevance of N-acetyltransferase 1 and 2 (NAT1, NAT2) genetic polymorphisms in non-small cell lung cancer susceptibility.

The highly polymorphic N-acetyltransferases (NAT1 and NAT2) are involved in both activation and inactivation reactions of numerous carcinogens, such as tobacco derived aromatic amines. The potential effect of the NAT genotypes in individual susceptibility to lung cancer was examined in a hospital based case-control study consisting of 392 Caucasian lung cancer patients [152 adenocarcinomas, 173 squamous cell carcinomas (SCC) and 67 other primary lung tumours] and 351 controls. In addition to the wild-type allele NAT1*4, seven variant NAT1 alleles (NAT1*3, *10, *11, *14, *15, *17 and *22) were analysed. A new method based on the LightCycler (Roche Diagnostics Inc.) technology was applied for the detection of the polymorphic NAT1 sites at nt 1088 and nt 1095. The NAT2 polymorphic sites at nt 481, 590, 803 and 857 were detected by polymerase chain reaction-restriction fragment length polymorphism or LightCycler. Multivariate logistic regression analyses were performed taking into account levels of smoking, age, gender and occupational exposure. An increased risk for adenocarcinoma among the NAT1 putative fast acetylators [odds ratio (OR) 1.92 (1.16-3.16)] was found but could not be detected for SCC or the total case group. NAT2 genotypes alone appeared not to modify individual lung cancer risk, however, individuals with combined NAT1 fast and NAT2 slow genotype had significantly elevated adenocarcinoma risk [OR 2.22 (1.03-4.81)] compared to persons with other genotype combinations. These data clearly show the importance of separating different histological lung tumour subtypes in studies on genetic susceptibility factors and implicate the NAT1*10 allele as a risk factor for adenocarcinoma.

Aged↗
PubMed2001

Glutathione-S-transferase M1, M3, T1 and P1 polymorphisms and susceptibility to non-small-cell lung cancer subtypes and hamartomas.

Polymorphic glutathione-S-transferase (GST) genes causing variations in enzyme activity may influence individual susceptibility to lung cancer. In this case-control study (consisting of 389 Caucasian lung cancer patients, including 151 adenocarcinomas (ACs) and 172 squamous cell carcinomas (SCCs), and 353 hospital control subjects without malignant disease, genotype frequencies for GSTM1, GSTM3, GSTP1 and GSTT1 were determined by polymerase chain reaction (PCR)/ restriction fragment length polymorphism (RFLP)-based methods. While adjusted odds ratios (ORs) indicated no significantly increased risk for lung cancer overall due to any single GST genotype, the risk alleles for GSTM1, GSTM3 and GSTP1 conferring reduced enzyme activity were present at higher frequency in SCC than in AC patients. This is consistent with a reduced detoxification of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from cigarette smoke that are more important for the development of SCC than for AC. An explorative data analysis also identified statistically significantly increased ORs for the combinations GSTT1 non-null and GSTP1 GG or AG for lung cancer overall (OR 2.23, CI 1.11-4.45), and for SCC (OR 2.69, CI 1.03-6.99). For lung cancer overall, and especially among SCC patients, the GSTT1 null genotype was underrepresented (SCC 11.2% v. control subjects 19%, P = 0.026, OR 0.57, CI 0.30-1.06). Additionally, in 28 patients with hamartomas, the GSTT1 null genotype was also protective (P = 0.013), while GSTP1 variant allele carriers were overrepresented (OR 2.48, CI 1.06-6.51). In conclusion, GST genotypes may act differently, either by detoxifying harmful tobacco carcinogens and/or by eliminating lung cancer chemopreventive agents. The latter role for GSTT1 would explain the observed lower risk of SCC and hamartoma associated with GSTT1 null. Further confirmatory studies are required.

Adenocarcinoma↗
PubMed2001

Adjuvant radio-chemotherapy in stage II-III rectal cancer with 24-hour infusion of high-dose 5-fluorouracil and folinic acid: evaluation of feasibility.

BACKGROUND: Postoperative radio-chemotherapy has been established as standard treatment for stage II and III rectal cancer patients in the last decade. To improve the efficacy of this therapy, we decided to evaluate continuous 24-hour infusion of 5-fluorouracil (5-FU) with folinic acid (FA) in combination with local radiation versus standard bolus 5-FU/FA with local radiation in a randomized study. Here we report on the first 28 patients to receive the experimental treatment. PATIENTS AND METHODS: Patients with stage II and III rectal cancer received weekly 2-hour infusions of FA 500 mg/m2 followed by continuous 24-hour infusions of 5-FU 2,600 mg/m2 postoperatively via a Port-A-Cath system. The first cycle included 8 consecutive weekly administrations, the 1st-4th in full dose, the 5th-8th with 50% reduced dose while local irradiation (45 or 50.4 Gy) was performed. Thereafter, two further chemotherapy cycles (6 weekly administrations, 100% dose) followed. RESULTS: 28 patients received continuous 5-FU/FA treatment, of whom only 21 were evaluable for tolerability. 19 patients (90.4%) completed the first cycle, only 14 patients entered the second treatment cycle. Especially during the combined radiochemotherapy, increased toxicity was observed with grade III/IV diarrhea (n = 2), nausea (n = 1), leukopenia (n = 1), and cardiac toxicity (n = 1). CONCLUSION: The high rate of premature treatment dropout indicate that the chosen schedule of weekly high-dose 5-FU/FA continuous infusion and combined postoperative radiotherapy should not be recommended for further use in postoperative adjuvant treatment.

Adenocarcinoma↗