Influence of prostatic disease and prostatic manipulations on the concentration of prostate-specific antigen.

We examined the influence of different factors [benign prostatic hyperplasia (BPH), prostatic carcinoma (PCA), organ volume, weight of resected tissue, transurethral catheter] on the serum prostate-specific antigen (PSA) levels in 253 patients with BPH (n = 138; 54%) and PCA (n = 115; 46%). Only in 57.2% of the BPH patients, PSA values were < 4 ng/ml, in 74.6% < 7 ng/ml. In 108 patients with BPH, a transurethral prostatectomy was performed. PSA values correlated significantly with the sonographically determined prostatic volumes and less precisely with the weight of the resected tissue. The PSA concentration per milliliter of prostatic volume was 0.12 ng/ml, per gram of resected tissue it was 0.21 ng/ml. An incidental PCA was found in 12/108 patients (11%). The PSA values were identical with those of the total collective in regard to volume and tissue weight. In 11 patients, we examined possible alterations of the PSA values before and until 24 h after prostatic massage. Only insignificant alterations were seen, a massive increase was not found in any patient. Searching for an absolutely valid 'normal value' appears hardly appropriate. However, the usefulness of PSA is increased when the sonographically determined prostatic volume is included. A rectal examination of the prostate has no influence on the PSA value.