Presentation Authors: Lucas W. Dean*, Hikmat A. Al-Ahmadie, Ying-Bei Chen, Anuradha Gopalan, S. Joseph Sirintrapun, Satish K. Tickoo, Victor E. Reuter, Samson W. Fine, New York, NY
Introduction: The diagnosis of atypical small acinar proliferation (ASAP) on prostatic needle biopsy (NB) is associated with a 30-40% cancer detection rate on subsequent NB. In the era of active surveillance, many men with low risk disease are managed expectantly. The percentage of cancers of low-grade and low-volume (LG/LV: Gleason score (GS) 3+3=6, â‰¤ 3 cores, â‰¤ 60% of any core) detected after an ASAP diagnosis is not well-studied. We evaluated follow-up NB pathology findings in patients with an initial ASAP diagnosis, including a subset who went on to radical prostatectomy (RP).
Methods: We identified 167 patients with an ASAP diagnosis on their first NB at our institution over a 13-year period. 70/167 had at least one follow-up NB. We determined number of follow up NB, pathologic findings in each NB and highest grade/quantity of cancer detected. 16/70 subsequently underwent RP and pathologic results were also reviewed.
Results: Of 70 patients, 48 (69%) had 1 follow-up NB, 13 (19%) had 2 and 9 (14%) had >2 (range: 3-6). Median followup from initial ASAP diagnosis in men who did not undergo radical treatment was 4.8 years. 28/70 (40%) patients had cancer on their first repeat NB, 18 with LG/LV disease. Overall, 34/70 (49%) on patients were diagnosed with cancer on any subsequent NB. _x000D_
In 54/70 (77%) patients, repeat NB ranged from benign to LG/LV, including: benign [n=21], ASAP [n=11], PIN [n=4] or LG/LV [n=17]. One additional patient had 4 cores of GS6 disease, with 5% max involvement. _x000D_
5/18 with LG/LV findings had RP that revealed GS 6, organ-confined disease [n=4] of which 3 had dominant anterior tumors or GS 3+4=7 with focal extraprostatic extension in a dominant anterior tumor [n=1]._x000D_
In 16/70 (23%), subsequent NB revealed more significant cancer, including: GS 3+4=7 [n=12], GS 4+3=7 [n=2], GS 4+4=8 [n=1] or GS 5+4=9 [n=1]. _x000D_
11/16 patients with GS â‰¥7 underwent RP, 10/11 showing dominant anterior tumors (8 exclusively anterior dominant) with GS 3+4=7 [n=7], GS 4+3=7 [n=3], or GS 4+3=7 with tertiary pattern 5 [n=1]. 7 had organ-confined disease and 4 had extraprostatic extension.
Conclusions: Approximately 75% of patients with ASAP show either no cancer or active surveillance-eligible disease in this cohort, with implications for the work-up of atypical foci. As the overwhelming majority of patients who showed GS â‰¥7 cancer on subsequent biopsy had dominant anterior tumors at RP, increased attention to the anterior prostate should be a routine part of the management of patients with an ASAP diagnosis.
Source of Funding: This research was funded in part through the NIH/NCI Cancer Center Support Grant P30 CA008748.