[The role of PSA in diagnosis of prostate cancer and its recurrence].

Prostate specific antigen is the most important tumor marker of prostate cancer. PSA, in conjunction with digital rectal examination, is the first-line clinical tool for detection of prostate cancer. To improve its specificity PSA-density, PSA-ratio (fPSA/tPSA), PSA-velocity, and complexed PSA have been introduced into clinical praxis. The treatment of lower stage disease in younger men has resulted in a longer period of post-treatment cancer surveillance. Biochemical recurrence is an early indicator for clinical disease recurrence. PSA doubling time allows to distinguish between local and systemic progression and is also a valid predictor for distant metastasis and death of disease.