[1005] Utility of Saturation Prostate Biopsy in Detection of Aggressive Prostate Cancer

Liza M Quintana, Ashley Ward, Elizabeth Genega, Huihui Ye. Beth Israel Deaconess Medical Center, Boston, MA

Background: The goal of early detection of prostate cancer (PCa) is to detect localized aggressive cancer at a curable stage. Currently, a biopsy scheme of 10 to 12 cores is recommended to optimize the ratio of cancer detection to biopsy-related morbidity. Studies found that initial saturation biopsy showed no significant increase in cancer detection rate but is associated with increased adverse events. However, almost all those studies use “any cancer vs no cancer” as the end point. We examined accuracy of saturation biopsy in detection of high grade cancer (Gleason pattern 4 and above) in pre-radical prostatectomy (RP) biopsies, in comparison with that of 12-core biopsy.
Design: We reviewed clinical data and pathology reports of 73 consecutive patients diagnosed with PCa through saturation biopsy (18-29 cores, median=20 cores) prior to immediate RP at our hospital from 2003 to 2012. The control group included 272 consecutive patients who had undergone 12-core biopsies either at our hospital (N=170) or at outside hospital with slides reviewed in house (N=102) prior to immediate RP at our hospital from 2005 to 2012. Slides of all available pre-RP biopsies and corresponding RP specimens will be reviewed by two urological pathologists.
Results: Saturation biopsy, in-house 12-core biopsy, and outside 12-core biopsy had a sensitivity of 65.2%, 63.8% and 67.1%, respectively, and a specificity of 66.7%, and 93.0%, and 80.8%, respectively, in predicting the presence of high grade cancer in the RP specimens. 16 of 34 (47.1%) men who had only Gleason pattern 3 detected on saturation biopsies were found to have Gleason pattern 4 or 5 in their RP specimens, compared to 71 in 132 men (53.8%) in the 12-core group (p=0.483, chi-square test). Surprisingly, 9 of 39 (23.1%) patients who had Gleason pattern 4 PCa detected on saturation biopsies were found to have Gleason pattern 3 only in their RP specimens. The Gleason downgrading rate was significantly higher than the 5.7% (8 in 140) in the 12-core group (p=0.003, Fisher's Exact Test).
Conclusions: Compared with 12-core biopsy, saturation biopsy is associated with 6.7% less chance of Gleason upgrading in immediate RP specimens, suggesting that saturation biopsy is slightly more sensitive in detecting high grade PCa. Surprisingly, a 17.4% higher rate of Gleason downgrading was seen in RP specimens after saturation biopsy than those after 12-core biopsy. An unbiased review of all biopsy and their corresponding RP slides will provide explanations for this unexpected finding.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 181, Tuesday Afternoon

 

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