Biomarkers and Personalized Medicine in Prostate Cancer – Advent of Precision Oncology in (Radio) Therapy Decision-Making

Therapy decision-making in prostate cancer has traditionally been limited to clinical, histopathological, and radiological variables that does not take into account the varying biology of prostate cancer manifestations. It is well-known that disease stratification tools we use in our clinics every day to customize therapy choices for individual patients with prostate cancer fail to capture and address the wide ranges of observed disease clinical courses. Prostate cancer is characterized by significant intra- and interpatient heterogeneity that makes this disease unique and extremely variable. The advent of affordable next-generation genomic sequencing techniques has allowed the incorporation of these data into clinical research, with enormous potential to aid clinical care in the future. The optimal goal of prostate cancer treatment is to personalize treatment specific to a patient’s unique clinic-genomic phenotypes. We may thus potentially avoid overtreatment in patients harboring less aggressive disease and undertreatment in patients harboring more aggressive disease. Currently, we lack that ability if we rely only on clinical stratification tools such as the NCCN model, CAPRA scoring, and D’Amico classification. It may be the case that prostate cancer genomics hold the key to understanding and predicting the response to crucial treatment modalities in prostate cancer: androgen deprivation therapy, radiotherapy, and next-generation androgen pathway inhibition therapy. Currently, there are many open questions about how to use these therapies optimally in individual patients. In this freeform narrative review, we summarize the literature and current clinical practice of biomarkers in prostate cancer, specifically focusing on genomic tests utilized in radiotherapy management and/or adjunctive therapies given with radiotherapy.