Effect of transurethral resection on serum free/total prostate-specific antigen levels in patients with benign prostatic hyperplasia

Abstract

Objectives. Transurethral resection of the prostate (TURP) can cause elevation of total serum prostate-specific antigen (PSA). However, the effect of these procedures on free PSA and percent free PSA is still unknown. The aim of this study was to investigate the effect of TURP on serum total PSA, free PSA, and free/total (f/t) PSA ratio in patients with benign prostatic hyperplasia (BPH) and to determine the reliability of f/t PSA ratio after such interventions. Methods. Fifty-three patients with BPH who underwent TURP because of severe bladder outlet obstruction symptoms were included in this study. All patients underwent digital rectal examination and transrectal ultrasound (TRUS), and routine hematologic (complete blood count) and serum biochemical tests, urine analysis, and a peak urinary flow test were performed. Serum total PSA and free PSA levels were determined 1 hour before and 24 hours after TURP by using enzyme immunometric assay. Preoperative and postoperative free and total PSA and f/t PSA ratio were statistically compared. Results. Although postoperative total PSA and free PSA increased significantly compared with preoperative values ( P<0.001 and P = 0.024, respectively), the difference between preoperative and postoperative f/t PSA ratios was not statistically significant ( P = 0.103). Conclusions. Finding no significant change in f/t PSA ratio, although there is a significant increase in the serum levels of total and free PSA, suggests to us that f/t PSA ratio may be a more reliable parameter in the early period after such interventions as TURP.