[Prostate carcinoma: prostate-specific antigen--and then what?].

Based on its exclusive organspecificity, prostate specific antigen (PSA) holds a key role in diagnosis and follow up of prostatic carcinoma. for intermediate PSA levels of 4-10 ng/mL, differentiation from benign prostatic hyperplasia is difficult and the indication for biopsy must be judged individually. Basically, diagnosis is only indicated in those patients, in whom there are therapeutic consequences. The same is true for the use of PSA in follow up after therapy. Further measures should be based on the symptoms of the patient rather than on a laboratory value.