Clinical implications of prostate-specific antigen (PSA)

Prostate-specific antigen(PSA) is currently the tumour marker of choice for prostatic carcinoma. This article examines the current literature on the application of PSA for cancer detection (concentrating on values of PSA in the normal and 'grey' areas of 2.5-10 ng/ml), in staging of the disease and prediction of treatment response. These areas in particular have been refined by the use of PSA indices (PSA density, velocity, age ranges) and the article focuses on the recent studies analysing their standing in clinical practice.