The Prostate CAncer gene 3 (PCA3) test has mainly been investigated for guiding the decision on performing a (repeat) prostate biopsy. It gives an indication about the probability of finding prostate cancer in the prostate biopsy. If the PCA3 Score is high, the probability of finding prostate cancer in the biopsy is high which indicates that a biopsy may be performed. Preliminary findings show that the PCA3 Score may also give an indication about the significance or aggressiveness of the cancer (see also  http://www.pca3.org/public/about-pca3en and http://www.pca3.org/pro/pca3-utility ). This could aid in the decision on which treatment should be given, e.g. if active surveillance or watchful waiting can be continued or if active treatment is indicated. The higher the PCA3 Score, the higher the probability that the cancer is/has become significant, which could be confirmed by a new biopsy. However, the results of this study should be confirmed in future clinical trials.