Assessment of prostate cancer gene 3 (PCA3) test as a strategy to improve the specificity of biopsies in men suspected to this tumor

• Grant number: 14/24536-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2015
• End date: July 31, 2017
• Field of knowledge: Health Sciences - Collective Health - Preventive Medicine
• Principal Investigator: Eliney Ferreira Faria
• Grantee: Eliney Ferreira Faria
• Host Institution: Hospital do Câncer de Barretos. Fundação Pio XII (FP). Barretos , SP, Brazil
• Associated researchers: André Lopes Carvalho ; Rui Manuel Vieira Reis

Abstract

Prostate-specific antigen (PSA) and digital rectal examination (DRE) are the two main tools in the detection of prostate cancer (PC). However, these methods are not so reliable when used in men with persistent suspicious of PC after an initial negative biopsy. It is known that between 25-30% of men will be diagnosed with PC in the second prostate biopsy. The downside is that the other 70-75% will undergo rebiopsies unnecessarily, which will cause anxiety, and possible complications. In the past decade, molecular markers have emerged with the purpose of trying to screen the cases with greater chances of positive rebiopsies, including Gene Prostate Cancer 3 (PCA3). The detection of this gene is made by a nucleic acid amplification assay that is highly expressed in cancerous prostate cells, and their detection in the urine is practical and feasible. This gene is 66 times more expressed in prostate cancer than in benign pathologies.ObjectiveEvaluate the use of PCA3 in men with persistent suspicion of PC in order to reduce repeated biopsies. Materials and Methods: A prospective evaluation of one hundred and sixty (n = 150) men between 45 and 75 years of age in need of rebiopsy of the prostate due to the persistently high PSA (between 2.5 and 10 ng / ml) and/or abnormal DRE after at least one negative biopsy for PC. The project has been approved by the Ethics Committee in Research of Fundação Pio XII - Barretos Cancer Hospital (524/2011) and all patients are going sign the informed consent form. Before the rebiopsy each man will be submitted to a post-DRE urine sample to PCA3 assay; Prostate needle biopsies will be performed aiming at 16 or more fragments. The PCA3 analysis will be performed in the Research Center On Molecular Oncology (RCMO). The prostate biopsies will be analyzed by the same pathologist of the Pathology Department. All the Departments involved in this study belong to the Barretos Cancer Hospital. The statistical analysis of sensitivity, specificity, positive predictive value, negative predictive value, ROC curve for the PCA3 will be performed separately and also in combination with clinicals parameters. (AU)