From Urology Times

Spanish researchers have found a means of distinguishing between high-grade prostatic intraepithelial neoplasia (HGPIN) lesions destined to become cancerous and those that will remain benign, which may spare patients the discomfort and inconvenience of unnecessary needle biopsies, according to a study in Clinical Cancer Research (2008; 14:2617-22).

This is teh first studay that I am familiar with that has a genetic marker for patients with diagnosis of high grade PIN. High grade PIN was once thought to be higly associated with prostate cancer (about 50%) and warranted a repeat biopsy. This was when urologists performed 6 biopsies routinely.
Now that we are performing at least 10, the finding is not as ominous as before. About 20% of pateints wil develop cancer.