Once a treatment for prostate cancer (PCa) has been implemented, prostate specific antigen (PSA) remains the best tumour marker available and gives an indication about the probability of recurrence of the cancer. Monitoring your PSA level over time may help to indicate if your cancer has recurred and whether further therapy is needed.

The Prostate CAncer gene 3 (PCA3) test is not a replacement for PSA. It is an additional marker to help decide if, in men concerned about having PCa, a prostate biopsy is really needed to diagnose PCa [see: http://www.pca3.org/public/about-pca3en ]. Based on recent publications, it seems that PCA3 test could also be useful to monitor men who choose active surveillance/ watchful waiting [see: http://www.pca3.org/public/questions-answersen/question-2-4/view  ].

In contrast, there are currently no data available on the value of the PCA3 test for monitoring disease response and recurrence after local therapy (i.e. radical prostatectomy, external beam radiation therapy (EBRT), interstitial radiation therapy, or high intensity focused ultrasound (HIFU)) or systemic therapy (i.e. hormone therapy or chemotherapy).