The Clinical Usefulness of Prostate Cancer Biomarkers: Current and Future Directions

Worldwide, prostate cancer (PCa) is the leading cause of morbidity and cancer-related mortality in men. The pathogenesis of PCa is complex and involves abnormal genetic changes, abrogation of cell growth with heterogeneous progression and predictive subgroups. In the last two decades there have been the exploration and development of molecular and genetic biomarkers for PCa due to limitations of traditional serum biomarkers such as prostate specific antigen (PSA) in screening and diagnosis. These biomarkers could possibly differentiate between PCa and benign prostatic hyperplasia (BPH) patients, and healthy controls as well as assist with prognosis, risk stratification and clinical decision-making. Such molecular biomarkers include serum (PHI and 4K score), urine (PCA3 and SelectMDx), and tumor tissue (Oncoytype DX, Decipher and Prolarix). microRNAs (miRNAs) deregulation where there is increased or decreased expression levels, constitute prospective non-invasive molecular biomarkers for the diagnosis and prognosis of PCa. There are also other emerging molecular biomarkers such as exosomal miRNAs and proteins that are in various stages of development and clinical research. This review is intended to provide a wide-ranging appraisal of the literature on current and emerging PCa biomarkers with robust evidence to afford their application in clinical research and by extension routine clinical practice