[1043] Features of Atypical Glands on initial Prostate Biopsy as Positive or Negative Predictors of Malignancy on Subsequent Prostate Biopsy

Sriram Venigalla, Chen Zhao, Hiroshi Miyamoto. University of Rochester, Rochester, NY

Background: Patients whose prostate biopsy reveals the presence of atypical glands suspicious for prostatic carcinoma (AGSC) are subject to close monitoring and repeat biopsies, perhaps unnecessarily, as clinicians do not have a clear basis for understanding and stratifying the significance of these findings. The value of histologic atypia on an initial prostate biopsy in predicting the detection of prostate cancer on subsequent biopsies should thus be further studied.
Design: In a retrospective, blinded manner, we examined the initial biopsies of 82 patients (93 foci) reported as AGSC. Five factors assessed in these biopsies include the size of the nucleoli of cells composing AGSC (graded on a scale of 1-4 with "1" denoting small, inconspicuous nucleoli and "4" denoting macronucleoli), the presence of high-grade prostatic intraepithelial neoplasia (HGPIN) adjacent to or separate from AGSC, the number of AGSC, the presence of intraluminal crystalloid, mucin, or dense secretions within AGSC, and the presence of basal cells in AGSC highlighted by immunohistochemical staining.
Results: On subsequent biopsies, 31 (38%) patients were found to have prostate cancer (PCA) while no carcinoma was identified in the remainder (62%) of cases (NOCA). Nucleolar grade was significantly higher (p=0.010) in PCA cases (mean ± SD: 2.43 ± 0.80) than in NOCA cases (mean ± SD: 1.98 ± 0.70). Adjacent (p=0.235) and separate (p=0.132) HGPINs were found in 8/37 (22%) foci and 8/31 (26%) cases in PCA, respectively, and in 6/56 (11%) foci and 6/51 (12%) cases in NOCA, respectively. The number of atypical glands was similar (p=0.950) between PCA (mean ± SD: 7.03 ± 5.35) and NOCA (mean ± SD: 7.09 ± 4.18). The presence of intraluminal crystalloid, mucin, or dense secretions in AGSC did not show a statistically significant correlation between PCA [5/37 (14%)] and NOCA [13/56 (23%)] (p=0.293). Immunohistochemical stains demonstrated patchy basal cells in 17/39 (44%) of NOCA whereas basal cells were absent in 24/27 (89%) PCA (p=0.006).
Conclusions: On an atypical initial prostate biopsy, the size of nucleoli in AGSC is a positive predictor of prostate cancer on subsequent biopsy. On the other hand, as expected, even patchy staining of basal cells in AGSC represents a negative predictor of prostate cancer. However, HGPIN adjacent to or separate from AGSC, the total number of AGSC, and intraluminal materials do not reliably predict the subsequent diagnosis of prostate cancer.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 1:00 PM

Poster Session II # 188, Monday Afternoon

 

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