Long-term follow-up of men with isolated high-grade prostatic intra-epithelial neoplasia followed by serial delayed interval biopsy

Objectives: To analyze the outcomes of serial delayed interval biopsy (DIBx) in men with isolated high-grade prostatic intraepithelial neoplasia (HGPIN). The natural history of isolated HGPIN is poorly defined. Since January 2000, we have monitored men with isolated HGPIN using DIBx every 3 years, regardless of the change in prostate-specific antigen (PSA) level.

Methods: The institutional biopsy records from 1996 onward were reviewed to identify the men with isolated HGPIN found on 12-core needle biopsy specimens who had undergone a minimum of 1 DIBx in our follow-up strategy. Patient age, biopsy and prostatectomy pathologic outcomes, and longitudinal PSA measurements were recorded.

Results: A total of 112 men had undergone a first DIBx and 47 had undergone a second DIBx at the last follow-up examination at a mean of 34.4 and 66.2 months after the HGPIN diagnosis, respectively. Prostate cancer was found in 25 (22.3%) of 112 men and 11 (23.4%) of 47 men at DIBx-1 and DIBx-2, respectively. The PSA velocity was not predictive of cancer during short-term follow-up. Of the men diagnosed with cancer, 63.6% had a Gleason score of ≥7, and 9 (81.8%) of 11 men had clinically significant disease (Gleason score of ≥7 and/or >5% cancer volume) at surgery. All cancers were organ confined at and surgery.

Conclusions: Men with isolated HGPIN have a continued risk of developing prostate cancer during long-term follow-up, regardless of the changes in the serum PSA level. Collectively, the relatively high likelihood of organ confinement and clinically significant cancer suggest empiric DIBx every 2-3 years could be a valuable tool in the follow-up of men with isolated HGPIN found by extended core biopsy.