Biomarker assays and MRI-fusion biopsy in the detection of Prostate Cancer
Prostate cancer over-diagnosis and over treatment for indolent disease is an area of concern. Various biomarkers and MRI findings have been utilized to improve the predictability of the prognosis.
To determine the correlation between commercially available biomarkers (PSA, PCA3, Neogenomics Assay, OPKO4K, etc.) with findings on multi-parametric MRI and prostate biopsy specimens. 1. To Predict the probability of PCa diagnosis and behavior prior to performing an invasive prostate biopsy. 2. Describe the rate of disagreement in Gleason scores determined from 12-core biopsy versus targeted biopsy. 3. Identify predictors of “Gleason Score Upgrading”.
Design, setting, and participants:
A retrospective chart review was performed to collect the data for the patients seen in the Urology Clinic of the Medical center of the University of California, Irvine. The data from 331 patients were collected for this review.
Outcome measurements and statistical analysis: The assay results of all biomarkers and MRI findings, as available, was compared to the recent pathological diagnosis of prostate biopsy. The highest Gleason score noted on pathology was considered for positive biopsy.
The mean patient age was 65 years and mean PSA level was 7.72ng/ml. The overall cancer detection rate was 49.52% (119 of 226 patients). PCA3 was found to have better predictability for a positive biopsy results (OR: 1.04(1.01-1.07); p=0.004) and. PI-RADS score 3 predicted against positive biopsy outcomes (OR: 1.43(1.01-2.02); p=0.019) and PI-RADS score 5 predicted positive biopsy outcomes (OR: 7.69(3.04-19.41); p=<0.001). MRI/US-fusion-guided biopsies resulted in Gleason score upgrading in 26% of cases, and among those upgraded cases, 30% were upgraded to clinically significant disease. We also found that the standard 12-core biopsy method resulted in Gleason score upgrading of 28% of cases, and among those upgraded cases, 21% were upgraded to clinically significant disease. On multivariate analysis, MP-MRI suspicion, Age, and PSA above 10 were associated with Gleason score upgrading in the targeted lesions.
PCA3 and MP-MRI findings can be considered to predict the outcomes of prostate biopsies and patients who are likely to get benefit from prostate biopsy can be selected and sparing the patients harboring indolent disease. MRI/US-fusion-guided biopsies resulted in Gleason score upgrading in 26% cases, among those upgraded cases, 30% were upgraded to clinically significant disease. MRI/US-fusion-guided biopsy missed more cases of less aggressive disease and fewer cases of highly aggressive disease as compared to standard 12-core TRUS biopsy.