Clinical management of prostatic intraepithelial neoplasia as diagnosed by extended needle biopsies

To examine the results of the clinical management of patients with high-grade prostatic intraepithelial neoplasia (PIN), as diagnosed by extended needle biopsies.

The clinical data were reviewed from a cohort of 387 men who underwent > or = 10 core prostate needle biopsies between 1 January 1996 and 31 December 1997 by one urologist (W.C.D.). Two study groups were identified; the first comprised 47 patients with only high-grade PIN and the second was a control group of 137 patients with only benign findings on their biopsies. Those patients with cancer, atypia or a prostatic biopsy with fewer than 10 cores were excluded. The clinical and histological data were evaluated. The criteria for re-biopsy were two successive increases in prostate specific antigen (PSA) level or any change in the findings on digital rectal examination (DRE). All patients were monitored at 6-12 month intervals.

Of the 387 patients, 46% had normal findings, 5.2% had atypia, 12.6% had PIN alone, 15 (3.9%) had PIN plus atypia, 6.7% had PIN plus cancer and 32.3% had cancer. There was no significant difference between the PIN and control groups in age, DRE, PSA level, prostate size (by ultrasonography), free testosterone level, number of the cores and time of follow-up (median 34.8 and 36.6 months for the PIN and control groups, respectively). Of the PIN and control groups, 21 (45%) and 43 (31%) respectively had at least one re-biopsy. Five patients (24%) in the PIN and one (2.3%) in the control group developed cancer (P = 0.0124). All these patients had organ-confined disease and were found to have either Gleason scores 3 + 3 or 3 + 4 on surgical specimens. There was no correlation between the original location of PIN and the location of subsequent malignancy.

Patients with one set of extended needle biopsies with high-grade PIN should be followed clinically every 6-12 months, and it may be safe to reserve repeat biopsy for those with changes in PSA level and/or in the DRE.