Effect of Transurethral Surgery on Serum Percent Free Prostate-Specific Antigen Levels

Kim, Dong Woo; Ryu, Dong Soo; Oh, Tae Hee

Abstract

PURPOSE: Transurethral surgery can cause an elevation of the total serum prostate- specific antigen (PSA); however, the effect on the free (PSA-F) and free-to-total PSA (f/t PSA) ratio is still unknown. The aim of this study was to investigate the effect of transurethral surgery on the serum total PSA (PSA-T), PSA-F and the f/t PSA ratio, in patients with benign prostatic hyperplasia (BPH) or a bladder tumor.
MATERIALS AND METHODS
Thirty-five patients with BPH and 48 with a bladder tumor, who had undergone transurethral surgery, were included in this study. The serum PSA-T and PSA-F levels were determined before, and at 1 and 7 days after, the transurethral surgery, using an immunoradiometric assay. The Pre- and postoperative PSA-T, PSA-F and f/t PSA ratios were statistically compared.
RESULTS
On the first postoperative day, the PSA-T and PSA-F levels increased significantly compared with the preoperative values (p<0.05) oin the transurethral resection of the prostate (TURP) group, which were related to the volume of the resected prostate (p=0.038, r=0.352 and p=0.004, r=0.473, respectively), while the irrigating fluid volume and operative time were not. The postoperative f/t PSA ratio was not changed significantly after the transurethral resection of the bladder tumor (TURB) (p>0.05). In contrast, a mean 1.4-fold increase (29.13%) in f/t PSA ratio was noted 1 day after the TURP, but a mean 0.7-fold decrease (13.71%) was noted 7 day after, compared to preoperative mean value (20.24%).
CONCLUSIONS
Both TURB and TURP caused an immediate increase in the serum PSA level, which was related to the resected volume of the prostate in the BPH patients. Our recommendation is that a serum f/t PSA ratio should not be obtained for at least 1 week after a TURP. For the purpose of improving the clinical availability of PSA, the f/t PSA ratio determination could be accurate and reliable following a TURB.