TRANSURETHRAL BIOPSY OF PROSTATE AFTER MULTIPLE NEGATIVE TRANSRECTAL BIOPSIES 14 1

71 patients

I 52 benign

-1 37 benign 1 1 cancer 4 PIN

I I Y PIN

r--+--l 9 benign 6 cancer 4 PIN

FIG. 2. Breakdown of final pathological diagnosis based on initial diagnosis. PIN, prostatic intraepithelial neoplasia.

finding a malignancy in the transition zone. However, 3 of the 5 patients with prostatic intraepithelial neoplasia in the transition zone subsequently had malignancy in the periph- eral zone, which raises the possibility of a relationship be- tween prostatic intraepithelial neoplasia in the transition zone and overt prostate cancer in the peripheral zone, al- though the number of patients in this study is clearly too small to draw a definitive conclusion.

The low yield of prostate cancer in the transurethral biopsy and transition zone specimens may have several explana- tions in this high risk population. As discussed previously, transurethral biopsy and transition zone prostatic needle biopsy sample the periurethral or transition zone of the pros- tate, where only a minority of the prostate cancers are found. Thus, the expected yield of any biopsy of this region would be low. Furthermore, the patients reviewed in this study had already undergone a minimum of sextant prostatic needle biopsies and, therefore, were essentially a screened popula- tion and would be less likely to have large or multifocal tumors amenable to localization by transurethral biopsy or transition zone prostatic needle biopsy. The possibility that the magnitude of the individual transurethral biopsy speci- mens was inadequate to diagnose prostate cancer must be considered. The median transurethral biopsy specimen weighed 0.90 gm. and consisted of a minimum of 4 transure- thral resection chips. The specimens, which included the positive transurethral biopsies, did not have significantly larger resection volumes than the median resected specimen weight (0.75 and 1.50 versus 0.90 gm.). It is possible that the volume of tissue sampled was inadequate and, thus, undiag- nosed tumor remains to be found in the transition zone. However it is difficult to justify transurethral resection of significant amounts of tissue in these patients given the wide spatial sampling of transrectal ultrasound guided peripheral zone and transition zone sampling. In addition the morbidity would be expected to increase with the resection of larger amounts of tissue.

CONCLUSIONS

We found transurethral biopsy as an adjunctive study to be of minimal value in diagnosing prostate cancer in patients with persistently elevated PSA after a previously negative biopsy. Given the added risk and cost of anesthesia, the significant potential morbidity and the low likelihood of a positive biopsy, transurethral biopsy is probably not war- ranted in patients who have already had a negative prostatic needle biopsy. Patients with tumors on transurethral biopsy probably can be diagnosed via serial transrectal ultrasound guided sextant prostatic needle biopsies.

REFERENCES

1. McNeal, J. E., Redwine, E. A., Freiha, F. S. and Stamey, T. A.: Zonal distribution of prostatic adenocarcinoma: correlation with histologic pattern and direction of spread. Amer. J. Surg. Path., 12 897, 1988.

2. Keetch, D. W., Catalona, W. J. and Smith, D. S.: Serial prostatic biopsies in men with persistently elevated serum prostate specific antigen values. J. Urol., 151: 1571, 1994.

3. Lui, P. D., Tems, M. R, McNeal, J. E. and Stamey, T. A:

Indications for ultrasound guided transition mne biopsies in the detection of prostate cancer. J. Urol., la 1O00, 1995.

4. Catalona, W. J., Smith, D. S., Ratliff, T. L., Dodds, K M., Coplen, D. E., Yuan, J. J. J., Petros, J. A. and Andriole. G. L.: Mea- surement of prostate-specific antigen in serum as a screening test for prostate cancer. New Engl. J. Med., 324: 1156, 1991.

5. Keetch, D. W. and Catalona, W. J.: Prostatic transition zone biopsies in men with previous negative biopsies and persis- tently elevated serum prostate specific antigen values. J. Urol., 15L: 1795, 1995.

6. Bazinet, M., Karakiewicz, P. I., Aprikian, A. G., Trudel, C., Aronson, S., Nachab6, M.. PBloquin, F., Dessureault, J., Gayal. M., Zheng, W., BBgin, L. R. and Elhilali, M. M.: Value of systemic transition zone biopsies in the early detection of prostate cancer. J. Urol., lS& 605, 1996.

7. Schmidt. J. D., Mettlin, C. J.. Natarajan. N.. Peace, B. B., Beart, R. W., Jr., Winchester, D. P. and Murphy, G. P.: Trends in patterns of care for prostatic cancer, 1974-1983: results of surveys by the American College of Surgeons. J. Urol., 136: 416, 1986.

8. Greene. D. R., Wheeler, T. M., Egawa, S., Dunn, J. K. and Scardino, P. T.: A comparison of the morphological features of cancer arising in the transition zone and in the peripheral zone of the prostate. J. Urol., 148. 1069, 1991.

EDITORIAL COMMENT

Factors predicting the need for repeat biopsies of the prostate in men who have undergone 1 previous segmental (sextant) biopsy remain controversial. Some authors have suggested that PSA den- sity may be useful in this setting, while others do not.' In addition, the free-to-total PSA ratio may also serve to indicate whether repeat biopsy is likely to be useful. Another question is what the extent of repeat biopsy should include, that is should simple sextant biopsies be repeated or are transition zone biopsies and even transurethral resection biopsies (4 quadrants) indicated.

The authors demonstrate that transurethral resection quadrant biopsies in this setting do not yield a greater number of patients with cancer than simple repeat sextant biopsies with or without transi- tion zone biopsies, and that an increased complication rate is asso- ciated with transurethral resection biopsies. Thus, routine transure- thral resection quadrant biopsies do not appear to be useful in this setting. Also, this article suggests the value of repeat segmental biopsies (and not transurethral resection quadrant biopsies) in the patient with high grade prostatic intraepithelial neoplasia identified on the original biopsy. In this series, while 6 of 19 such patients demonstrated cancer on repeat segmental biopsies (and 4 of 19 had high grade prostatic intraepithelial neoplasia), no patient had cancer or prostatic intraepithelial neoplasia on transurethral resection quadrant biopsies. I believe this information strongly supports the practice of repeat segmental biopsies in patients with previously documented high grade prostatic intraepithelial neoplasia and symp toms of prostatism before recommending transurethral resection of the prostate.

Finally, we must remember the difference between transurethral resection quadrant biopsies and complete transurethral resection of the prostate in determining the presence of cancer. In patients with significant obstructive symptoms who are candidates for transure- thral resection of the prostate we can expect more than 17% of men to have prostate cancer detected by complete surgical transurethral resection. Ornstein et al previously reported that neither a previous negative segmental biopsy, serum FSA nor PSA density influenced the likelihood of finding cancer on complete traneurethral d o n of the pmtate.2 In their sene8 16% of patienta with 00

142 TRANSURETHRAL. BIOPSY OF PROSTATE AFTER MULTIPLE NEGATIVE TRANSRECTAL BIOPSIES

biopsy had cancer as compared to 17.2% of those who had 1 or more prior biopsies.*

Robert C. Flanigan Department of Urology Loyola University School of Medicine Maywood, Illinois

1. Olson, M. C., Posniak, H. V., Fisher, S. G., Flisak, M. E., Salomon, C. G., Flanigan, R. C., Waters, W. B. and Pyle, J. M.:

Directed and random biopsies of the prostate: indications based on combined results of transrectal sonography and prostate-specific antigen density determinations. AJR, 163: 1407, 1994.

2. Omstein, D. K., Rao. G. S., Smith, D. S. and Andriole, G. L.: The impact of systematic prostate biopsy on prostate cancer inci- dence in men with symptomatic benign prostatic hyperplasia undergoing transurethral resection of the prostate. J. Urol., 157: 880, 1997.