RESUMEN
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is one of the most common malignant tumours and is still associated with a poor prognosis in advanced disease. To improve the standard therapy with gemcitabine, we initiated a prospective randomised phase-II trial with gemcitabine (GEM) versus gemcitabine plus sunitinib (SUNGEM) based on data of in vitro trials and phase-I data for the combination treatment. The rational of adding sunitinib was its putative antiangiogenic mechanism of action. METHODS: A total of 106 eligible patients with locally advanced, unresectable or metastatic PDAC without previous system therapy were randomised to receive GEM at a dosage of 1.000mg/m(2) d1, 8, 15 q28 versus a combination of SUNGEM at a dosage of GEM 1.000mg/m(2) d1+8 and sunitinib 50mg p.o. d1-14, q21d. The primary end-point was progression free survival (PFS), secondary end-points were overall survival (OS), toxicity and overall response rate (ORR). RESULTS: The confirmatory analysis of PFS was based on the intend-to-treat (ITT) population (N=106). The median PFS was 13.3 weeks (95% confidence interval (95%-CI): 10.4-18.1 weeks) for GEM and 11.6 weeks for SUNGEM (95%-CI: 7.0-18.0 weeks; p=0.78 one-sided log-rank). The ORR was 6.1% (95%-CI: 0.7-20.2%) for GEM and for 7.1% (95%-CI: 0.9-23.5%) for SUNGEM (p=0.87). The median time to progression (TTP) was 14.0 weeks (95%-CI: 12.4-22.3 weeks) for GEM and 18.0 weeks (95%-CI: 11.3-19.3 weeks) for SUNGEM (p=0.60; two-sided log-rank). The median OS was 36.7 weeks (95%-CI: 20.6-49.0 weeks) for the GEM arm and 30.4 weeks (95%-CI: 18.1-37.6 weeks) for the SUNGEM (p=0.78, one-sided log-rank). In regard to toxicities, suspected SAEs were reported in 53.7% in the GEM arm and 71.2% in the SUNGEM arm. Grade 3 and 4 neutropenia was statistically significantly higher in the SUNGEM arm with 48.1% versus 27.8% in the GEM arm (p=0.045, two sided log-rank). CONCLUSIONS: The combination SUNGEM was not sufficient superior in locally advanced or metastatic PDAC compared to GEM alone in regard to efficacy but was associated with more toxicity.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Carcinoma Ductal Pancreático/tratamiento farmacológico , Desoxicitidina/análogos & derivados , Indoles/uso terapéutico , Pirroles/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/administración & dosificación , Desoxicitidina/administración & dosificación , Desoxicitidina/uso terapéutico , Europa (Continente) , Femenino , Humanos , Indoles/administración & dosificación , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Pirroles/administración & dosificación , Sunitinib , Resultado del Tratamiento , GemcitabinaRESUMEN
INTRODUCTION: Nimotuzumab is a humanized monoclonal antibody that binds to the EGFR. Based on phase I data, the recommended dose has been established at 200 mg weekly. This study was aimed at evaluating the safety and efficacy of nimotuzumab monotherapy in patients (pts) with locally advanced or metastatic pancreatic cancer. METHODS: Pts who failed first line standard chemotherapy for advanced disease and had at least one measurable lesion were eligible for the study. Nimotuzumab was given intravenously at 200 mg once weekly for 6 weeks (wks). Follow up by CT scan was performed after 8 weeks. Pts continued receiving treatment 3-weekly until disease progression or unacceptable toxicity occurred. Endpoints included tumor response (RECIST), progression-free survival (PFS), and safety. RESULTS: A total of 56 pts were enrolled for treatment (ECOG status of 1 [n = 41] or 0 [n = 15]), the majority (47 pts) had metastatic disease. Nearly half of the pts [n = 26] received ≥2 regimens. Pts evaluable for response: n = 36; CR: 0; PR: 0; SD: 6 pts. Median PFS for pts with SD was 19.2 weeks, for all pts 6.7 weeks (95% CI: 6.43-7.14 weeks). PFS after 1 year was 10.3% with a median overall survival of 18.1 weeks. Treatment-related adverse events were generally mild including rash grade 1 in 5 pts. After a single dose of 200 mg, the t(1/2) was calculated to 45 h. CONCLUSION: These data confirm that nimotuzumab is safe and very well tolerated. To improve efficacy, a randomized, placebo-controlled trial with Gem has been initiated.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Receptores ErbB/inmunología , Neoplasias Pancreáticas/tratamiento farmacológico , Adenocarcinoma/patología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias Pancreáticas/patologíaRESUMEN
BACKGROUND: Despite limited clinical efficacy, treatment with dacarbazine or temozolomide (TMZ) remains the standard therapy for metastatic melanoma. In glioblastoma, promoter methylation of the counteracting DNA repair enzyme O(6)-methylguanine-DNA-methyltransferase (MGMT) correlates with survival of patients exposed to TMZ in combination with radiotherapy. For melanoma, data are limited and controversial. METHODS: Biopsy samples from 122 patients with metastatic melanoma being treated with TMZ in two multicenter studies of the Dermatologic Cooperative Oncology Group were investigated for MGMT promoter methylation. We used the COBRA (combined bisulphite restriction analysis) technique to determine aberrant methylation of CpG islands in small amounts of genomic DNA isolated from paraffin-embedded tissue sections. To detect aberrant methylation, bisulphite-treated DNA was amplified by PCR, enzyme restricted, and visualised by gel electrophoresis. RESULTS: Correlation with clinical data from 117 evaluable patients in a best-response evaluation indicated no statistically significant association between MGMT promoter methylation status and response. A methylated MGMT promoter was observed in 34.8% of responders and 23.4% of non-responders (P=0.29). In addition, no survival advantage for patients with a methylated MGMT promoter was detectable (P=0.79). Interestingly, we found a significant correlation between MGMT methylation and tolerance of therapy. Patients with a methylated MGMT promoter had more severe adverse events, requiring more TMZ dose reductions or discontinuations (P=0.007; OR 2.7 (95% CI: 1.32-5.7)). Analysis of MGMT promoter methylation comparing primaries and different metastases over the clinical course revealed no statistical difference (P=0.49). CONCLUSIONS: In advanced melanoma MGMT promoter, methylation correlates with tolerance of therapy, but not with clinical outcome.
Asunto(s)
Antineoplásicos/uso terapéutico , Metilación de ADN , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Dacarbazina/análogos & derivados , Melanoma/tratamiento farmacológico , Regiones Promotoras Genéticas , Proteínas Supresoras de Tumor/genética , Antineoplásicos/efectos adversos , Secuencia de Bases , Cartilla de ADN , Dacarbazina/efectos adversos , Dacarbazina/uso terapéutico , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Temozolomida , Resultado del TratamientoAsunto(s)
Anticuerpos Monoclonales/uso terapéutico , Receptores ErbB/antagonistas & inhibidores , Neoplasias Pancreáticas/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales/farmacocinética , Anticuerpos Monoclonales Humanizados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patologíaRESUMEN
The prognosis for lung cancer patients treated with chemotherapy is poor. Single nucleotide polymorphisms (SNPs) in matrix metalloproteinase (MMP) genes could influence treatment outcome by altering apoptotic pathways. Eight SNPs with known or suspected phenotypic effect in six genes (MMP1, MMP2, MMP3, MMP7, MMP9 and MMP12) were investigated. For 349 Caucasian patients with primary lung cancer, receiving first-line chemotherapy, three different endpoints were analysed: response after the second cycle, progression free survival (PFS) and overall survival (OS). The prognostic value of the SNPs was analysed using multiple logistic regression for all patients and histology-, stage- and treatment-specific subgroups. Hazard ratio estimates for PFS and OS were calculated using Cox regression methods. None of the investigated polymorphisms modified response significantly in the whole patient population. However, tumour stage IIIB variant allele carriers of MMP2 C-735T showed a significantly worse response. PFS was significantly prolonged in MMP1 G-1607GG variant allele carriers and OS in small cell lung cancer patients carrying the MMP12 A-82G variant allele. In conclusion, this study identified SNPs in MMP1, MMP2, MMP7 and MMP12 for further investigation as possible predictors of chemotherapy outcome in lung cancer patients.
Asunto(s)
Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Polimorfismo de Nucleótido Simple , Anciano , Alelos , Antineoplásicos/farmacología , Estudios de Cohortes , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Metaloproteinasa 2 de la Matriz/genética , Persona de Mediana Edad , Polimorfismo Genético , PronósticoRESUMEN
Sorafenib is a multi-kinase inhibitor with antiangiogenic and antiproliferative activity. The activity of sorafenib in progressive hormone-refractory prostate cancer (HRPC) patients was investigated in a phase II clinical study. Progressive HRPC patients received sorafenib 400 mg bid p.o. continuously. Only patients with no prior chemotherapy, and either one-unidimensional measurable lesion according to RECIST-criteria or increasing prostate-specific antigen (PSA) values reflecting a hormone-refractory situation, were eligible for study entry. The primary study objective was the rate of progression-free survival of >/=12 weeks (PFS12). Secondary end points were overall response, overall survival, and toxicity. Fifty-seven patients with PC were enrolled. Two patients had to be withdrawn from the set of eligible patients. According to RECIST criteria, 4 patients out of 55 evaluable patients showed stable disease (SD). According to PSA-response, we saw 11 patients with SD PSA and 2 patients were responders at 12 weeks (PFS12=17/55=31%). Among the 257 adverse events, 15 were considered drug related of maximum CTC-grade 3. Twenty-four serious adverse events occurred in 14 patients (14/55=26%). Seven of them were determined to be drug related. No treatment-related death was observed. Sorafenib has antitumour activity in HRPCP when evaluated for RECIST- and PSA-based response. Further investigation as a component of combination regimens is necessary to evaluate its definite or overall clinical benefit for HRPCP.
Asunto(s)
Bencenosulfonatos/uso terapéutico , Neoplasias de la Próstata/tratamiento farmacológico , Piridinas/uso terapéutico , Anciano , Anciano de 80 o más Años , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Bencenosulfonatos/efectos adversos , Fatiga/inducido químicamente , Humanos , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Niacinamida/análogos & derivados , Dolor/inducido químicamente , Compuestos de Fenilurea , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/patología , Piridinas/efectos adversos , Sorafenib , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
The objective of this study was to improve the vehicular emissions inventory for the light- and heavy-duty fleet in the metropolitan area of São Paulo (MASP), Brazil. To that end, we measured vehicle emissions in road tunnels located in the MASP. On March 22-26, 2004 and May 04-07, 2004, respectively, CO, CO2, NOx, SO2, and volatile organic compounds (VOCs) emissions were measured in two tunnels: the Janio Quadros, which carries light-dutyvehicles; and the Maria Maluf, which carries light-duty vehicles and heavy-duty diesel trucks. Pollutant concentrations were measured inside the tunnels, and background pollutant concentrations were measured outside of the tunnels. The mean CO and NOx emission factors (in g km(-1)) were, respectively, 14.6 +/- 2.3 and 1.6 +/- 0.3 for light-duty vehicles, compared with 20.6 +/- 4.7 and 22.3 +/- 9.8 for heavy-duty vehicles. The total VOCs emission factor for the Maria Maluf tunnel was 1.4 +/- 1.3 g km(-1). The main VOCs classes identified were aromatic, alkane, and aldehyde compounds. For the heavy-duty fleet, NOx emission factors were approximately 14 times higher than those found for the light-duty fleet. This was attributed to the high levels of NOx emissions from diesel vehicles.
Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Monitoreo del Ambiente/métodos , Combustibles Fósiles/análisis , Emisiones de Vehículos/análisis , Movimientos del Aire , Contaminantes Atmosféricos/química , Brasil , Monóxido de Carbono/análisis , Vehículos a Motor , Óxido Nítrico , Hidrocarburos Policíclicos Aromáticos/análisis , TransportesRESUMEN
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.
Asunto(s)
Carcinógenos/toxicidad , Alimentos/normas , Mutágenos/toxicidad , Animales , Pruebas de Carcinogenicidad , Europa (Continente) , Enfermedades Transmitidas por los Alimentos/etiología , Enfermedades Transmitidas por los Alimentos/genética , Humanos , Pruebas de Mutagenicidad , Medición de Riesgo , Organización Mundial de la SaludRESUMEN
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.
Asunto(s)
Vacunas contra el Cáncer/administración & dosificación , Dacarbazina/uso terapéutico , Células Dendríticas/trasplante , Melanoma/terapia , Péptidos/administración & dosificación , Humanos , Melanoma/patología , Metástasis de la NeoplasiaRESUMEN
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.
Asunto(s)
Corticoesteroides/efectos adversos , Dexametasona/efectos adversos , Resistencia a Antineoplásicos/efectos de los fármacos , Neoplasias Urológicas/terapia , Apoptosis , Femenino , Humanos , Masculino , Tolerancia a Radiación/efectos de los fármacos , Neoplasias Urológicas/tratamiento farmacológico , Neoplasias Urológicas/radioterapiaRESUMEN
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.
Asunto(s)
Antineoplásicos/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Colorrectales/tratamiento farmacológico , Dexametasona/farmacología , Neoplasias Hepáticas/tratamiento farmacológico , Animales , Antiinflamatorios no Esteroideos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis , Línea Celular Tumoral , Femenino , Glucocorticoides/metabolismo , Humanos , Ratones , Ratones Desnudos , Metástasis de la Neoplasia , Trasplante de NeoplasiasRESUMEN
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.
Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Antineoplásicos/uso terapéutico , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/mortalidad , Medición de Riesgo/métodos , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales de Origen Murino , Quimioterapia Adyuvante/métodos , Estudios de Cohortes , Neoplasias del Colon/patología , Neoplasias del Colon/cirugía , Supervivencia sin Enfermedad , Femenino , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Factores de Riesgo , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
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.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Cisplatino/administración & dosificación , Desoxicitidina/análogos & derivados , Desoxicitidina/administración & dosificación , Neoplasias Pulmonares/tratamiento farmacológico , Vinblastina/análogos & derivados , Vinblastina/administración & dosificación , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Cisplatino/efectos adversos , Desoxicitidina/efectos adversos , Esquema de Medicación , Enfermedades Hematológicas/inducido químicamente , Humanos , Persona de Mediana Edad , Calidad de Vida , Tasa de Supervivencia , Vinblastina/efectos adversos , Vinorelbina , GemcitabinaRESUMEN
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.
Asunto(s)
Pruebas de Carcinogenicidad/métodos , Neoplasias Experimentales/inducido químicamente , Animales , Biometría , Pruebas de Carcinogenicidad/estadística & datos numéricos , Bases de Datos Factuales , Ratones , Ratas , Factores de TiempoAsunto(s)
Seguridad de Productos para el Consumidor/normas , Contaminación de Alimentos/análisis , Alimentos/normas , Sustancias Peligrosas/efectos adversos , Suplementos Dietéticos/análisis , Suplementos Dietéticos/normas , Unión Europea , Alimentos/efectos adversos , Aditivos Alimentarios/análisis , Aditivos Alimentarios/normas , Contaminación de Alimentos/prevención & control , Guías como Asunto , Sustancias Peligrosas/análisis , Humanos , Micronutrientes/normas , Nivel sin Efectos Adversos Observados , Medición de Riesgo/métodos , Medición de Riesgo/normas , Gestión de RiesgosRESUMEN
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.