Implementation of repeat biopsy and detection of cancer after a diagnosis of atypical small acinar proliferation of the prostate.

Current guidelines recommend a repeat biopsy within 3-6 months after an initial diagnosis of atypical small acinar proliferation (ASAP) due to the high incidence of cancer detection on repeat biopsy. The current study sought to investigate practice patterns after a diagnosis of ASAP in a real-world setting and examine the clinicopathological outcomes of repeat biopsy. The departmental database of the Hyogo Prefectural Nishinomiya Hospital identified 97 of 1,218 patients with a diagnosis of ASAP on initial biopsy from 2011 to 2016. Clinical and pathological data were retrospectively analyzed. Of the 97 patients, 34 (35.1%) underwent a repeat biopsy. Patients with a repeat biopsy had a significantly higher prostate-specific antigen (PSA) velocity and shorter PSA doubling time than patients without a repeat biopsy (P=0.0002), and of these 34 patients with a repeat biopsy, 16 (47.1%) were diagnosed as having cancer. Multivariate logistic regression analysis revealed that a small prostate (P=0.0250) and advanced age (P=0.0297) were associated with cancer detection on repeat biopsy. Of the 16 cancers identified, 13 (81.6%) were diagnosed with a Gleason score >6. The results indicated that the implementation of a repeat biopsy for patients with ASAP could be affected by clinical characteristics in real-world settings, despite the current recommendation of guidelines endorsing immediate repeat biopsy. Prostate volume and age would aid in the decision-making process to perform repeat biopsy in patients with high PSA velocity and short PSA doubling time after a diagnosis of ASAP.