Effect of extracorporeal shockwave lithotripsy on serum prostate specific antigen concentration.

Abstract

We investigated the effect of extracorporeal shockwave lithotripsy (SWL) on the serum prostate specific antigen (PSA) concentration. A total of 22 male patients with a mean age of 52.9 years (range 37-67 years) were treated with SWL for distal ureteral calculi close to the ureteral orifice. Serum samples were drawn for measurement of PSA values just before (PSA-1) and 45 minutes (PSA-2) and 7 days (PSA-3) after the session. None of the patients had urinary tract infection or any abnormal finding on digital rectal examination. The SWL sessions were performed with the Wolf piezoelectric 2300 lithotripter that has a therapeutic focus of 3 x 11 mm. The mean number of shockwaves per patient was 2204. Student's t-test was used for statistical analysis. At 1 year, all patients completed a questionnaire concerning recent diagnosis of prostate cancer. The mean total PSA concentration before SWL was 3.13 ng/mL and rose to 3.91 ng/mL 45 minutes after the session. The mean PSA-3 value was 3.76 ng/mL. The mean free PSA values were 0.80, 0.83, and 0.77 ng/mL, respectively. The difference between PSA-1 and PSA-2 was statistically significant; all of the other differences were not significant. None of the patients reported prostate cancer at 1 year. Shockwave lithotripsy affects prostate epithelial cells and may cause a minor rise in total serum PSA values. However, this rise does seem to impair the value of PSA in patients with undiagnosed prostate cancer.