The effect of transrectal ultrasonography (TRUS) including digital rectal examination (DRE) of the prostate on the level of prostate specific antigen (PSA)

OBJECTIVE: To study the effect of transrectal ultrasonography (TRUS) including digital rectal examination (DRE) of the prostate on serum prostate specific antigen (PSA). PATIENTS AND METHODS: In a diagnostic centre for general practitioners serum PSA was determined in patients before, immediately after, and one week after TRUS including DRE. In a small group of patients PSA was determined at various times after DRE and TRUS. RESULTS: The PSA levels showed a statistically significant rise of 20% immediately after DRE and TRUS. After 7 days the PSA levels had returned to their initial levels. This decrease appeared to occur within the first 24 h. CONCLUSION: When applying the diagnostic triad PSA, DRE and TRUS blood samples for PSA should preferably be taken before DRE and TRUS. If blood samples are taken afterwards, it is safe to do so after seven days.