In prostate cancer patients with rising prostate-specific antigens (PSAs) after primary local therapy, and at high risk of metastatic disease based on a high Gleason score or ISUP grades 4–5 and/or short PSA doubling time, androgen-deprivation therapy (ADT) was shown to be effective with or without salvage radiotherapy. This evidence concerns the gene KLK3 and prostate carcinoma.