RESUMO
Validated biomarkers predictive of response/resistance to anthracyclines in breast cancer are currently lacking. The neoadjuvant Trial of Principle (TOP) study, in which patients with estrogen receptor (ER)-negative tumors were treated with anthracycline (epirubicin) monotherapy, was specifically designed to evaluate the predictive value of topoisomerase II-alpha (TOP2A) and develop a gene expression signature to identify those patients who do not benefit from anthracyclines. Here we describe in details the contents and quality controls for the gene expression and clinical data associated with the study published by Desmedt and colleagues in the Journal of Clinical Oncology in 2011 (Desmedt et al., 2011). We also provide R code to easily access the data and perform the quality controls and basic analyses relevant to this dataset.
RESUMO
MOTIVATION: Survival prediction of breast cancer (BC) patients independently of treatment, also known as prognostication, is a complex task since clinically similar breast tumors, in addition to be molecularly heterogeneous, may exhibit different clinical outcomes. In recent years, the analysis of gene expression profiles by means of sophisticated data mining tools emerged as a promising technology to bring additional insights into BC biology and to improve the quality of prognostication. The aim of this work is to assess quantitatively the accuracy of prediction obtained with state-of-the-art data analysis techniques for BC microarray data through an independent and thorough framework. RESULTS: Due to the large number of variables, the reduced amount of samples and the high degree of noise, complex prediction methods are highly exposed to performance degradation despite the use of cross-validation techniques. Our analysis shows that the most complex methods are not significantly better than the simplest one, a univariate model relying on a single proliferation gene. This result suggests that proliferation might be the most relevant biological process for BC prognostication and that the loss of interpretability deriving from the use of overcomplex methods may be not sufficiently counterbalanced by an improvement of the quality of prediction. AVAILABILITY: The comparison study is implemented in an R package called survcomp and is available from http://www.ulb.ac.be/di/map/bhaibeka/software/survcomp/.
Assuntos
Neoplasias da Mama/diagnóstico , Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Algoritmos , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Feminino , Humanos , Modelos Biológicos , Fenótipo , Análise de SobrevidaRESUMO
The characteristic problems of an orthodontic treatment of the adult must be well known and analyzed with greatest attention by the specialist. It is, first of all, necessary to try to respect and, if possible, to meet the particular psychological requirements which the adult presents. This will help the relation between the orthodontist and the patient for the whole period of the treatment and will allow the orthodontist to make the most of the necessary collaboration that the patient can give. It is, therefore, necessary to consider the physiological limitations imposed by the age of the patient whose growth has come to an end. Only by means of analysis and application of such therapeutic requirements will it be possible to reach the success of our intervention.
