Current status of biomarkers for prostate cancer

Abstract

Prostate cancer (PCa) is a leading cause of cancer-related death of men globally. Since its introduction, there has been intense debate as to the effectiveness of the prostate specific antigen (PSA) test as a screening tool for PCa. It is now evident that the PSA test produces unacceptably high rates of false positive results and is not prognostic. Here we review the current status of molecular biomarkers that promise to be prognostic and that might inform individual patient management. It highlights current efforts to identify biomarkers obtained by minimally invasive methods and discusses current knowledge with regard to gene fusions, mRNA and microRNAs, immunology, and cancer-associated microparticles.

Figure 1

Biomaterials currently available for the identification of prostate cancer biomarkers. Common biological specimens for PCa research include blood, urine, semen and prostate tissue. Each biological sample has associated advantages and disadvantages that may affect clinical validation of biomarkers and adoption for routine testing. Human plasma contains the largest amount of human proteins that could serve as potential markers for PCa diagnosis and prognosis. Urine has become a popular source for proteomic biomarker discovery and analysis due to its non-invasive nature. It contains a vast array of markers that could distinguish between healthy BPH and malignant PCa. Semen is a relatively non-invasive material for analyzing prostate biomarkers. Proteins directly from the prostate are easily accessed; however, there is a compositional variability among patients that poses an issue. Finally, prostate tissue, although a rich source of potential PCa biomarkers, is the most invasive of sampling sites. Abbreviations: CTCs, circulating tumor cells; miRNA, micro RNA; AMACR; alpha-methylacyl-CoA racemase.