Prostate-specific antigen as a marker of prostate disease.

Serum prostate markers, in particular prostate-specific antigen (PSA), have truly revolutionised all aspects of the management of men with prostatic carcinoma (PCa), the most important application being related to its early detection and screening. Several studies have shown the clinical utility of PSA levels for staging patients with PCa, especially when associated with other parameters, such as tumour grade, digital rectal examination and transrectal ultrasound findings, to establish the likelihood of disease extension outside the gland and of positive lymph nodes. Also, serum PSA levels are useful in monitoring patients either after the initial diagnosis of PCa or following therapy.