Effect of inflammation and benign prostatic enlargement on total and percent free serum prostatic specific antigen

OBJECTIVE: To analyze the influence of inflammation and benign prostatic enlargement on total and percent free serum prostatic specific antigen (PSA). PATIENTS AND METHODS: Total and free PSA serum levels were determined in 284 patients with no evidence of cancer in the sextant ultrasound-guided biopsy. Double antibody immunoradiometric assay Tandem and Tandem free PSA were used. Benign tissue without inflammation was found in 23.2% of the patients (group 1), while in 68.3%, it was associated with chronic prostatitis (group 2) and with acute prostatitis in 8.4% (group 3). RESULTS: Median serum PSA was 7.8 ng/ml in group 1, 6.7 ng/ml in group 2 and 6.4 ng/ml in group 3, p>0.05. Median percent free PSA was 14.1, 15.6 and 16.4%, respectively, p>0.05. Multiple linear regression analysis showed that prostatic size was the only significant contributor to serum PSA concentration. Moreover, total PSA and prostatic size contributed significantly to the percent free serum PSA. Inflammation had no significant influence on total or percent free serum PSA. CONCLUSION: Inflammation has an important prevalence in cancer-free prostatic biopsy specimens. It seems to have no significant influence on total and percent free serum PSA. However, prostatic size seems to be the major contributor.