Does Rigid Cystoscopy Affect the Total Serum Prostate-Specific Antigen Levels?

In the present study, we aim to prospectively evaluate the effect of performing rigid cystoscopy (CPE) in urological patients on the total serum prostate-specific antigen (PSA) levels. The study design was a prospective observational study. After giving informed consent, urological patients visiting the outpatient clinic of our institution from November 2010 to March 2012 who satisfied our protocol entry/exclusion criteria were recruited into the present study. Blood sample was withdrawn 1 h prior to CPE for serum PSA estimation, and CPE was performed with a 17-Fr rigid cystoscope. Blood was again withdrawn at 1 and 24 h after CPE for serum PSA estimation. The study used paired samples test (two tailed) for statistical analysis. A total of 50 patients with mean age of 60 years underwent CPE. The baseline, 1-h, and 24-h post CPE mean serum PSA levels were 1.98 ± 2.25 (0.02-12.33), 2.90 ± 2.81 (0.3-14.26), and 3.04 ± 2.95 (0.2-15.03) ng/dl, respectively. The paired samples test (two tailed) revealed that the rise in the baseline PSA versus 1-h PSA and baseline PSA versus 24-h PSA was highly significant at P < 0.001 and P < 0.002, respectively; however, the 1-h PSA versus 24-h PSA rise was not so significant (P < 0.043). The present study demonstrated that rigid cystoscopy may be associated with a variable rise in the serum PSA that may persist for a period of up to or beyond 24 h. Thus, we believe that the history of recent cystoscopy must be taken into consideration while interpreting the serum PSA value in the routine urological setting, as this will reduce unnecessary prostate biopsies in patients with an elevated serum PSA. Therefore, it may be advisable to wait for 24-48 h before withdrawing blood for serum PSA estimation in patients with history of CPE in the previous 24-48 h.