Repeat biopsy strategy in men with isolated prostatic intraepithelial neoplasia on prostate needle biopsy.

PURPOSE

Isolated high grade prostatic intraepithelial neoplasia on needle biopsy of the prostate is a strong predictor of malignancy on repeat biopsy. However, the optimal repeat biopsy technique for these patients has not been defined.

MATERIALS AND METHODS

We reviewed the records of 66 men in whom isolated prostatic intraepithelial neoplasia was found on needle biopsy of the prostate. We evaluated the side and/or quadrant and grade of prostatic intraepithelial neoplasia on initial biopsy, and compared the findings to the location of cancer on repeat biopsy.

RESULTS

Of 66 men 31 (47%) had cancer on repeat biopsy, with disease on the same side of the prostate as prostatic intraepithelial neoplasia in 20 (64%). The quadrant locations of prostatic intraepithelial neoplasia and cancer matched in 6 of 12 cases (50%). Low and high grade prostatic intraepithelial neoplasia predicted the side of cancer on repeat biopsy in 3 of 5 (60%) and 17 of 26 (65%) cases, respectively.

CONCLUSIONS

Directing repeat biopsy solely to the side with prostatic intraepithelial neoplasia will miss cancer in approximately 35% of cases. The optimal repeat biopsy technique for patients with high grade prostatic intraepithelial neoplasia should include systematic biopsy of the prostate.