Abstract: Disclosed herein are methods of determining the risk of developing prostate cancer in a subject or determining whether a subject suffers from prostate cancer, the method comprising measuring the level of one or more polyamines in a fluid sample obtained from the subject, measuring at a variable selected from the group consisting of age, prostate volume (PV), prostate-specific antigen (PSA), digital rectal examination (DRE), and combinations thereof. Also disclosed herein are methods of determining the risk of developing prostate cancer in a subject or determining whether a subject suffers from prostate cancer, the method comprising obtaining a score value based on previously disclosed variables to predict the likelihood of the subject developing or having prostate cancer.