RESUMO
For rare diseases, standard treatments are often not available and essential study parameters are difficult or impossible to obtain. Therefore, designs of clinical trials for these diseases are often based on little information. Adaptive designs allow such trials to be started and to gain information during the study. Motivated by a trial for a rare subtype of renal-cell carcinoma, we present a two-stage adaptive design for right-censored time-to-event data and a two-sided test. After the first stage, one can stop for futility or continue with reestimated sample size. The properties of such designs are analyzed by simulation studies.
Assuntos
Ensaios Clínicos Fase II como Assunto/estatística & dados numéricos , Doenças Raras/tratamento farmacológico , Doenças Raras/mortalidade , Projetos de Pesquisa/estatística & dados numéricos , Algoritmos , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/mortalidade , Ensaios Clínicos Fase II como Assunto/métodos , Simulação por Computador , Interpretação Estatística de Dados , Humanos , Indóis/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/mortalidade , Modelos de Riscos Proporcionais , Pirróis/uso terapêutico , Tamanho da Amostra , Sirolimo/análogos & derivados , Sirolimo/uso terapêutico , Sunitinibe , SobrevidaRESUMO
PURPOSE: Epithelial-to-mesenchymal transition (EMT) plays a pivotal role in tumor invasion and dissemination. EMT occurs predominantly at the tumor edge where it is induced by cytokines, the extracellular matrix environment, or hypoxia. In the tumor cell, it is further mediated by several transcription factors and microRNAs. The aim of this study was to explore the expression of EMT-associated genes at the invasive front in colorectal cancer and to evaluate their prognostic significance. EXPERIMENTAL DESIGN: We evaluated the expression of 13 EMT-associated genes at the invasion front of 30 colorectal liver metastases by quantitative real-time PCR. Immunostaining against zinc finger E-box-binding homeobox 2 (ZEB2) was carried out on 175 primary colorectal cancer specimens and 30 colorectal liver metastases and correlated to clinical and histopathologic data. DLD-1 cells were transfected with siRNA and subjected to migration and invasion assays. RESULTS: Gene expression analysis and immunohistochemistry showed an upregulation of ZEB2 at the invasion front in primary colorectal cancer and liver metastases. Overexpression of ZEB2 at the invasion front correlated significantly with tumor stage in primary colorectal cancer. Moreover, univariate and multivariate analysis revealed overexpression of ZEB2 at the invasion front as an independent prognostic marker for cancer-specific survival. Downregulation of ZEB2 by siRNA decreased the migration and invasion capacity of DLD-1 cells in vitro. CONCLUSIONS: Overexpression of ZEB2 at the invasion front correlates with tumor progression and predicts cancer-specific survival in primary colorectal cancer. Therefore, ZEB2 may be interesting as biomarker and potential target for treatment of colorectal cancer.
Assuntos
Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas Repressoras/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal/genética , Feminino , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundário , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Análise Multivariada , Invasividade Neoplásica , Prognóstico , Interferência de RNA , Proteínas Repressoras/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homeobox 2 de Ligação a E-box com Dedos de ZincoRESUMO
Current treatment protocols for Wilms tumor achieve 90% cure rates, but relapse risk and side effects from therapy remain challenging. Over the last decade, numerous markers have been proposed for classification and/or prediction of outcome. However, cohort sizes were quite variable and often small. We now provide a large-scale reassessment by real-time RT-PCR of 40 markers in 102 Wilms tumors followed by validation of potentially relevant markers in an independent set of 74 tumors. In the first data set, individual comparison with clinical data combined with adjustment for multiple testing and multivariate analysis revealed potentially relevant alteration of CA9, DKK1, EGR1, HEY2, MYC, MYCN, TERT, TOP2A, TRIM22, and VEGF expression in association with CTNNB1 mutation status, histological risk, response to chemotherapy, metastasis, relapse, or mortality. To further validate these data, potentially relevant genes for specific outcomes were reanalyzed in a second, independent tumor set. Here, univariate analysis confirmed the association of HEY2 with high-risk tumors and of TRIM22 with mortality. Even where significance levels could not be reached, the direction and extent of differential expression were generally reproducible. Multivariate analysis verified a weak correlation of TOP2A expression with metastasis and of TRIM22 with fatal outcome. Although we could corroborate only some of the previously reported associations of expression changes with clinical parameters, our results indicate that real-time RT-PCR analysis can facilitate further classification of Wilms tumor and prediction of outcome to adjust treatment accordingly. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.
