[761] Prostatic Adenocarcinoma and Status of Resection Margin of Radical Prostatectomy Associated with Core Biopsies with Atypical Small Acinar Proliferation or Minimal Cancer

TA Flood, BN Nguyen, EC Marginean, BM Purgina, KT Mai. The Ottawa Hospital, Ottawa, ON, Canada; The University of Ottawa, Ottawa, ON, Canada

Background: The finding of atypical small acinar proliferation (ASAP) in prostate biopsy cores has been previously investigated with repeat biopsies that show a rate of prostatic adenocarcinoma (PAC) ranging from 15 to 40%. The relationship between cancers missed on biopsy and cores positive for ASAP, minimal cancer, and absence of PAC has not been examined. In this study we use a model of hemiprostates corresponding to 5 cores associated with no cancer, ASAP, and minute cancers.
Design: The PAC biopsy negative hemiprostates of radical prostatectomy (RPs) specimens with biopsy proven contralateral PAC were examined. PAC negative hemiprostates with biopsy cores corresponding to minute cancers (group 1), ASAP (group 2) and no cancer (group 3) were obtained retrospectively from 2002 to 2008 from our institution. Groups 2 and 3 were subdivided into 2a/3a and 2b/3b for hemiprostates with or without PAC respectively.
Results: The interval from biopsy to RP ranged from 1 to 8 months. Of 637 total RPs, there were 31, 14, 18, 86 and 75 hemiprostates that fulfilled the criteria for groups 1, 2a, 2b, 3a and 3b respectively. There was a higher rate of PAC, including clinically significant PAC, in the hemiprostates associated with ASAP compared to non-ASAP hemiprostates. However, this difference was not statistically significant. Positive resection margins were observed in 2 cases. The biopsies for these 2 cases had demonstrated minute cancer and negative for cancer.
Conclusions: ASAP in needle core biopsy appears to be associated with an increased rate of PAC, however this increase was not statistically significant in the current study. There was no difference in the surgical resection margin status of RPs performed soon after an ASAP positive biopsy or following a delay of up to eight months. Furthermore, biopsies with ASAP were not associated with a higher rate of positive margins when compared to biopsies with minute cancer or negative for cancer.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 120, Monday Morning