The preclinical phase of biomarker developed is the foundation upon which translational and clinical validation can be built. Even though tissue-based proteomics has been widely performed [53–56], body fluid-based proteomics, albeit challenging, offers a non- or minimally-invasive alternative [57, 58] with comparable or even superior diagnostic accuracy to tissue-based proteomics, combined with greater suitability for large-scale screening or early detection methods. Potentially suitable body fluids for PCa biomarker discovery include urine, blood and semen. Liquid biopsy has been used for diagnosis of various cancer types [59–63], including PCa [64, 65]. Additionally, this technique has been found useful in cancer patient stratification, monitoring and screening .