Abstract
Forty-three patients had their serum concentrations of prostate specific antigen and activity of tartrate inhibited acid phosphatase measured before and after digital rectal examination, transrectal ultrasonography and transrectal core biopsy. Transrectal core biopsy significantly increased the values for both tumor markers but rectal examination and ultrasonography without biopsy had no such effect. The measurements returned to normal within one week of biopsy in all but four patients who still had slightly increased concentrations of prostate specific antigen. We recommend that the concentration of prostate specific antigen and activity of tartrate inhibited acid phosphatase are checked before biopsy of the prostate is carried on.