Natural history of widespread high grade prostatic intraepithelial neoplasia and atypical small acinar proliferation: should we rebiopsy them all?

Abstract

Objective To evaluate the premalignant potential of high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical small acinar proliferation (ASAP). Methods Patients diagnosed with monofocal HGPIN (mHGPIN), widespread HGPIN (≥4 cores, wHGPIN) and/or ASAP who underwent at least one rebiopsy during their follow-up, were enrolled. All enrollment biopsies underwent central pathologic revision. Risks for PCa were estimated using Fine and Gray method for competing risk. Results Pathologic revision changed the original diagnosis in 32.3% of cases. Among 336 cases enrolled, PCa was diagnosed in 164 (48.8%), and more specifically in 20 (30.3%) mHGPIN, 10 (34.5%) wHGPIN, 101 (54.0%) ASAP, and 33 (61.1%) HGPIN + ASAP (mean follow-up 124 months). Most PCa were Gleason score 6(3 + 3) (51.0%) and 7(3 + 4) (34.3%). On multivariate analysis, HGPIN + ASAP (HR 2.76, p < 0.001) and ASAP alone (HR 2.41, p < 0.001) were the only lesions significantly associated with PCa development. Of all cancers detected, 64.3% were at first rebiopsy. A rebiopsy performed within 3 months after ASAP diagnosis had a 45% chance of finding PCa. At Kaplan–Meier survival curves, median PCa-free survival was 48.1 months for HGPIN + ASAP and 64.9 months for ASAP (p 0.0005 at Log-rank test). At 1 year, 70% of HGPIN + ASAP, 73% of ASAP, 89% of wHGPIN, and 84% of mHGPIN were PCa-free. Conclusion The diagnosis of ASAP and HGPIN strongly relies on the expertise of dedicated uro-pathologists. Finding of ASAP is a strong risk factor for a subsequent PCa diagnosis, advising a rebiopsy, possibly within 3 months. m/wHGPIN should not be routinely rebiopsied.