taken from Small Gland, Big Problem 4th Edition
by Professor Roger Kirby, Health Press 2011
PSA, prostate-specific antigen, is a protein-like substance that occurs in abundance in the fluid within the prostate. Testing blood samples to determine the amount of PSA (a ‘PSA test’) is central to the early detection and selection of the most effective treatment for prostate cancer. Monitoring a man’s PSA level is also extremely helpful once therapy has been started, as it can indicate how effectively treatment is working. If the PSA is rising in spite of treatment, second-line therapies such as oestrogens or chemotherapy with, for example, Taxotere (docetaxel) may be in order.