Abstract: PD28-09
Sources of Funding: none

Introduction

It has been shown that transrectal ultrasound (TRUS)-guided saturation prostate biopsy (SB) improves detection of prostate cancer (PCa) progression or risk reclassification compared to extended prostate biopsy (EB) in patients who elect for active surveillance (AS). This study aims to compare the accuracy of MRI-fusion biopsy to SB in detecting PCa reclassification in patients on AS.

Methods

We reviewed 228 prostate biopsies from 177 patients diagnosed with PCa who elected AS. Only patients who fit the low risk NCCN criteria were included: Gleason score (GS) ≤ 6, PSA ≤ 10 ng/ml, clinical stage T1 or T2a, and percentage of positive cores ≤ 33% of total cores sampled at the time of diagnostic biopsy. Pathological progression or reclassification on surveillance biopsies was defined as no longer meeting the standard definition of low risk by Gleason score and/or disease volume.

Results

The mean age of men at diagnosis was 66.7 (SD ±8.3) years. Among 228 prostate biopsies, 53 were MRI fusion biopsies and 175 were SB (≥ 20 cores). Disease reclassification was seen in 77/175 (44%) of SB and 19/53 (36%) in MRI fusion biopsies. 13 of 19 patients underwent disease reclassification detected by a combination protocol of both MRI targeted and standard biopsy, while 6/19 were reclassified by MRI targeted biopsy alone. A greater degree of disease re-classification was seen with the SB technique as compared to both targeted-only MRI-fusion targeted biopsy (44% vs. 11.3%, P<0.0001) and combined systematic and targeted MRI fusion biopsy (44% vs. 24.5%, P=0.01). We further compared the rate of cancer progression (reclassification) at the time of each subsequent surveillance biopsy (Table 1, 2).

Conclusions

In patients with low risk PCa who elect for AS, we demonstrated that SB might confer a better rate of detection for reclassification than protocols involving MRI fusion techniques for confirmatory or surveillance biopsies at our institution.

Funding

none