Different clinical significance of ASAP/HGPIN pattern in systematic vs. MRI‑US fusion guided prostate biopsy

Atypical small acinar proliferation (ASAP) and high grade intraepithelial neoplasia (HGPIN) patterns identified at prostate biopsy yield an important clinical significance, their presence signaling an increased likelihood of future oncological development or underdiagnosed PCa. MRI and MRI-TRUS fusion prostate biopsy have recently become the standard for the diagnosis of prostate cancer. Thus, we aimed to assess the role of ASAP/HGPIN pattern in the context of these recent developments as compared with the standard systematic biopsy. The present study included 400 patients who underwent MRI-TRUS fusion prostate biopsy. A subgroup of these patients had a history of prior systematic biopsy and their results were also included in the analysis. We observed that ASAP/HGPIN pattern diagnosed at systematic biopsy is suggestive of a high-volume clinically-significant disease, most probably located outside the standard sampling area. On the contrary, ASAP/HGPIN at MRI-TRUS fusion biopsy has clinical features more similar to benign prostate hyperplasia, thus suggesting a more incipient disease, if present. No relation between concurrent ASAP/HGPIN and PCa was observed in our study.