Transurethral biopsy of the prostate for persistently elevated or increasing prostate specific antigen following multiple negative transrectal biopsies.

PURPOSE

Treatment of the patient with persistently elevated prostate specific antigen (PSA) levels after pathologically negative transrectal or manually directed prostate needle biopsy is unclear. We retrospectively evaluated the use of transurethral biopsy of the prostate as an adjunctive study for the diagnosis of prostate cancer in these patients.

MATERIALS AND METHODS

From January 1993 through February 1996, 71 patients underwent transurethral biopsy in conjunction with repeat prostatic needle biopsy for a persistently elevated PSA (greater than 4 ng./ml.) after previously negative needle biopsy. All patients had at least 1 previous ultrasound guided sextant prostatic needle biopsy (mean 1.85, range 1 to 7) with or without manually directed biopsies. Following negative prostatic needle biopsy these patients subsequently underwent a minimum of a 4-quadrant transurethral sampling of the prostatic fossa followed by repeat sextant prostatic needle biopsy. A subset of patients underwent sampling of the anterior prostatic tissue or transition zone using transrectal ultrasound guided prostatic needle biopsy at transurethral biopsy.

RESULTS

Of the 71 patients with elevated PSA (mean 16.2 ng./ml., range 4.2 to 171) 17 (24%) had prostate cancer on the repeat prostatic needle biopsy. Both patients who had prostate cancer on the transurethral biopsy specimens also had prostate cancer on the repeat prostatic needle biopsy specimens. A total of 68 patients had benign prostatic tissue and 1 had high grade prostatic intraepithelial neoplasia on transurethral biopsy specimens. Of 19 patients with high grade prostatic intraepithelial neoplasia on the initial prostatic needle biopsy, transurethral biopsy specimens revealed no prostate cancer or prostatic intraepithelial neoplasia. Repeat prostatic needle biopsy in these patients with high grade prostatic intraepithelial neoplasia revealed prostate cancer in 6 and high grade prostatic intraepithelial neoplasia in 4.

CONCLUSIONS

In patients with persistently elevated or increasing serum PSA after a previously negative prostatic needle biopsy, transurethral biopsy is not a useful adjunct in diagnosing prostate cancer. In this high risk group of patients transurethral biopsy adds little or no diagnostic value to prostatic needle biopsy even in those with high grade prostatic intraepithelial neoplasia.