Merrimen, J. L. et al. Multifocal high grade prostatic intraepithelial neoplasia is a significant risk factor for prostatic adenocarcinoma. J. Urol. 182, 485–490 (2009).

Patients with a diagnosis of high-grade intraepithelial neoplasia (HGPIN) on initial prostatic needle biopsy are at greater risk for subsequent prostatic adenocarcinoma than those with a benign diagnosis, a new study reveals. “This risk is most significant when the HGPIN is multifocal,” says co-investigator Jennifer Merrimen from the Queen Elizabeth II Health Science Center, Canada.

Previous studies have yielded conflicting data regarding the role of HGPIN as a risk factor for subsequent prostatic adenocarcinoma detection. “Many of these studies [have] small study numbers, so we addressed this issue using a large study population,” notes Merrimen.

Merrimen's team analyzed the pathological findings on prostatic needle biopsy in men whose data were collected in a Canadian database. The analysis focused on 1,409 men who, on initial prostatic needle biopsy, had a benign diagnosis or were diagnosed as having HGPIN and had at least 1 subsequent prostatic needle biopsy (845 and 564 patients in the benign and HGPIN groups, respectively). More patients were diagnosed as having prostatic adenocarcinoma on follow-up prostatic needle biopsy in the HGPIN than in the benign group (27.48% versus 22.01%, respectively). Compared with unifocal HGPIN, multifocal HGPIN was associated with a greater risk of prostatic adenocarcinoma.

“Our data suggest that men with multifocal HGPIN should be closely followed by a urologist and that a repeat biopsy at 1 year may be of value,” Merrimen concludes.