PSA stands for Prostate Specific Antigen. Small amounts are produced by the prostate in health and if there is prostate cancer, levels go up. So, the PSA can be used as a basic screening procedure to detect prostate cancer and also, for monitoring the effectiveness of treatment in prostate cancer. PSA levels do not tend to rise with the enlarged prostate – which is a completely different condition to prostate cancer.
Here’s more information about benign prostatic hyperplasia.