Prostate specific antigen in the diagnosis and staging of prostate cancer.

Prostate Specific Antigen (PSA) has revolutionized our approach to managing patients with an established diagnosis of cancer of the prostate (CaP). Moreover, its use in early detection and screening has resulted in the most sensitive method of detecting CaP. Furthermore it is regarded as the most important tumour marker in tumour biology. This article will discuss some important advances in the application of PSA.