Changes in serum prostate-specific antigen following prostatectomy in patients with benign prostate hyperplasia

Purpose: To investigate how prostatectomy for patients with benign prostate hyperplasia (BPH) affected the serum prostate-specific antigen (PSA) level s. Methods: In 193 patients who underwent prostatectomy for BPH, serum PSA lev els were measured before and three months after the operation. The total pr ostate weight measured by transrectal ultrasonography (TRUS) and the weight of the surgical specimen were examined in relation to the pretreatment PSA value and the changes in PSA levels after the operation. Results: The transition zone volume measured by TRUS could well estimate th e weight of the surgical specimen in patients who underwent subcapsular pro statectomy and transurethral resection of the prostate. The concentration o f preoperative serum PSA showed a significant correlation with the prostati c volume and with the transition zone volume. Removal of 1 g of BPH tissue reduced serum PSA levels by an average of 0.18 ng/mL. The change in serum P SA levels after the prostatectomy correlated with the total prostatic gland volume and with the transition zone volume. Conclusions: The elevated PSA levels in patients with BPH were caused by th e enlargement of the transition zone. After the resection of the adenoma, P SA levels should be expected to decrease to the normal range.