Prostate cancer is a clinically heterogeneous disease and remains the most common non-skin malignancy in men worldwide (Abate-Shen and Shen, 2000; Litwin and Tan, 2017), which is often diagnosed through screening with digital rectal examinations and quantitation of serum levels of prostate-specific antigen (PSA). At the morphological aspect, the Gleason scoring system is regarded as the most reliable and predictive histological grading system (Welch and Albertsen, 2009; Heidenreich et al., 2011). Interpatient genomic heterogeneity in prostate cancer is well recognized; however, molecular stratification of prostate cancer to guide treatment selection based on predictive genomic biomarkers remains an unmet clinical need (Prensner et al., 2012; Topalian et al., 2016).
