Strategy for repeat biopsy in patients with high grade prostatic intraepithelial neoplasia

The finding of high grade prostatic intraepithelial neoplasia in a biopsy specimen without prostate cancer warrants repeat biopsy because of the risk of concurrent cancer. However, to our knowledge the optimal repeat biopsy technique has not yet been defined. We determined the optimal subsequent biopsy strategy for detecting concurrent cancer in patients diagnosed with high grade prostatic intraepithelial neoplasia.

Of 63 men with isolated high grade prostatic intraepithelial neoplasia on initial biopsy 45 underwent repeat biopsy within 1 year. Certain biopsy patterns were used for repeat biopsy, including only the neoplasia site in 8 men, sextant in 12, sextant plus bilateral transition zone in 13 and 11 core multisite directed (sextant, bilateral transition zone, bilateral anterior horn of the peripheral zone and midline peripheral zone) in 12. We compared the location of high grade disease on the initial biopsy with the cancer site on repeat biopsy.

Repeat biopsy revealed cancer in 10 of the 45 men (22%), and the sites of high grade prostatic intraepithelial neoplasia and cancer correlated in 6. Cancer was detected at the sextant locations in 9 men. Of the 15 cores positive for cancer 8 were at the original high grade neoplasia site, 6 at a random sextant biopsy site and 1 in the transition zone. High grade disease was discovered bilaterally in 1 man, while prostatic intraepithelial neoplasia and cancer were detected on the same side in the remaining 9.

The optimal repeat biopsy strategy for patients with high grade prostatic intraepithelial neoplasia has not yet been determined but at a minimum it should include targeting the area of known high grade disease and the ipsilateral sextants.