[Early detection of prostate carcinoma. What diagnosis is of value when?]

Early detection of carcinoma of the prostate is based on digital rectal examination of the gland (DRE), transrectal ultrasonic exploration of the gland (TRUS) and determination of the prostate specific antigen (PSA) in the serum. The sensitivity of DRE along, but also in conjunction with TRUS is inadequate for early detection. Furthermore, two-thirds of all palpable prostate carcinomas have already breached the organ (T3), and are no longer curable by such local measures as radical prostatectomy or radio-therapy. Nevertheless, DRE is mandatory, since, when an induration is palpable, a prostate biopsy should be obtained even when the PSA is normal (< 4 ng/ml). Imaging procedures, such as TRUS or endorectal NMR have only a secondary role in early detection, while TRUS is indispensable for a controlled biopsy of the prostate. The most important early detection measure is the annual determination of PSA (syn. traditional or total PSA), during which both bound and free PSA is determined using an immunoassay. A chronic problem with the evaluation of serum levels of this organ marker - which is not an antigen specific for prostate carcinoma - is the fact that although it has an acceptable sensitivity (> 90%),its specificity is low (40% false positive findings). Attempts have been made to reduce the rate of unnecessary biopsies by measuring free PSA, PSA-density, age-corrected PSA or bound PSA. However, such attempts have failed to improve the efficacy of traditional PSA measurement in the individual case. In the guidelines relating to the diagnosis of prostate carcinoma established by the German urologists, the present recommendation requires PSA measurement once a year from the age of 45 onwards.