Incidence, surveillance and natural history of high-grade prostatic epithelial neoplasia in the era of multiparametric MRI and targeted biopsy.

[OBJECTIVES] To determine the incidence of isolated high grade prostatic epithelial neoplasia (iHGPIN) following magnetic resonance imaging (MRI)-ultrasonography co-registration fusion targeted biopsy (MRFTB) coupled with systematic biopsy (SB) and to assess the detection rates of clinically significant prostate cancer (csPCa).

[PATIENTS AND METHODS] Beginning in June 2012, most patients at our institution underwent multiparametric MRI (mpMRI) before prostate biopsy. Biopsies were performed between June 2012 and October 2021. The surveillance protocol for iHGPIN included prostate-specific antigen assessment every 6 months, digital rectal examinations annually, and multiparametric MRI (mpMRI) at 3 years. Repeat biopsies were recommended primarily for suspicious mpMRI, defined as a new Prostate Imaging-Reporting and Data System (PI-RADS) score >2 region of interest (ROI) or an increase in size of the pre-existing ROI.

[RESULTS] Of the 628 biopsies, 230 (33.7%), 48 (7.0%), 404 (59.2%) were interpreted as benign, iHGPIN, or prostate cancer (PCa), respectively. Of these cancers 140 (34.7%) and 264 (65.3%) were low-risk PCa and csPCa, respectively. iHGPIN was detected in MRRFTB only, SB only, and both MRFRB + SB in six (12.5%) 36 (75%), and six patients (12.5%), respectively. Of the 32 MRI scans performed at 3 years, a new PI-RADS score >2 ROI or an increase in the size or PI-RADS score of a pre-existing ROI was observed in four and eight patients, respectively. Nine of these underwent biopsy. Three additional biopsies were performed on non-suspicious mpMRI. csPCa was detected in two patients, both with an enlarging ROI.

[CONCLUSION] To our knowledge, this is the first study examining the incidence, natural history, and subsequent csPCa detection rates for iHGPIN in the era of mpMRI and MRI targeted biopsy. The lower prevalence of iHGPIN is attributed to the selection of biopsy candidates based on mpMRI and an increased likelihood of detecting pre-existing csPCa. Our findings provide compelling evidence that biopsy strategies limited to MRI targets will almost eliminate iHGPIN detection while decreasing detection of csPCa. A 3-year biopsy should be performed only in men with suspicious mpMRI.