A prospective evaluation of the prostate microbiome in malignant and benign tissue using transperineal biopsy.

BACKGROUND: The link between the prostate microbiome and prostate cancer remains unclear. Few studies have analyzed the microbiota of prostate tissue, and these have been limited by potential contamination by transrectal biopsy. Transperineal prostate biopsy offers an alternative and avoids fecal cross-contamination. We aim to characterize the prostate microbiome using transperineal biopsy. METHODS: Patients with clinical suspicion for prostate cancer who were to undergo transperineal prostate biopsy with magnetic resonance imaging (MRI) fusion guidance were prospectively enrolled from 2022 to 2023. Patients were excluded if they had Prostate Imaging Reporting and Data System lesions with scores ≤ 3, a history of prostate biopsy within 1 year, a history of prostate cancer, or antibiotic use within 30 days of biopsy. Tissue was collected from the MRI target lesions and nonneoplastic transitional zone. Bacteria were identified using 16S ribosomal RNA gene sequencing. RESULTS: Across the 42 patients, 76% were found to have prostate cancer. Beta diversity indices differed significantly between the perineum, voided urine, and prostate tissue. There were no beta diversity differences between cancerous or benign tissue, or between pre- and postbiopsy urines. There appear to be unique genera more abundant in cancerous versus benign tissue. There were no differences in alpha diversity indices relative to clinical findings including cancer status, grade, and risk group. CONCLUSIONS: We demonstrate a rigorous method to better characterize the prostate microbiome using transperineal biopsy and to limit contamination. These findings provide a framework for future large-scale studies of the microbiome of prostate cancer.

MRI at diagnostic versus confirmatory biopsy during MRI-based active surveillance of prostate cancer.

OBJECTIVES: Active surveillance (AS) is a management strategy for patients with favorable risk prostate cancer. Multi-parametric magnetic resonance imaging (mpMRI) may impact upgrading rates, but there is mixed evidence on the appropriate timing to introduce mpMRI. We evaluated timing of initial mpMRI use for patients on AS and compared upgrading and intervention rates for AS candidates who received initial mpMRI before diagnostic biopsy vs. confirmatory biopsy. SUBJECTS AND METHODS: Patients enrolled in AS captured by the Prospective Loyola Urology mpMRI (PLUM) Prostate Biopsy Cohort which captures men undergoing MRI-fusion prostate biopsy. We included patients enrolled in AS between January 2014 and October 2022. We conducted a retrospective analysis of patients who underwent MRI-fusion prostate biopsy while on AS at our institution. The cohort was stratified by men who underwent first mpMRI prior to diagnostic biopsy (MRI-DBx), confirmatory biopsy (MRI-CBx), or a subsequent surveillance biopsy. Oncologic outcomes including pathologic reclassification, intervention-free survival, progression-free survival, and overall survival were evaluated. RESULTS: Of 346 patients identified on AS, 94 (27.2%) received mpMRI at the time of diagnostic biopsy, 182 (52.6%) at confirmatory biopsy, and 70 (20.2%) at a later biopsy. At confirmatory biopsy (median 14 months), there was no difference in upgrading (HR 0.95, P = 0.78) or intervention rates (HR 0.97, P = 0.88) between MRI-DBx and MRI-CBx. PI-RADS score on initial mpMRI was associated with upgrading during AS follow-up relative to men with negative mpMRI (HR 4.20 (P = 0.04), 3.24 (P < 0.001), and 1.99 (P < 0.001) for PI-RADS 5, 4, and 3, respectively), and PSA density was associated with intervention (HR 1.52, P = 0.03). CONCLUSION: mpMRI can serve as a prognostic tool to select and monitor AS patients, but there was no difference in upgrading or intervention rates based on initial timing of MRI.

Variability in prostate cancer detection among radiologists and urologists using MRI fusion biopsy.

Objectives: The aim of this study is to evaluate the impact of radiologist and urologist variability on detection of prostate cancer (PCa) and clinically significant prostate cancer (csPCa) with magnetic resonance imaging (MRI)-transrectal ultrasound (TRUS) fusion prostate biopsies. Patients and methods: The Prospective Loyola University MRI (PLUM) Prostate Biopsy Cohort (January 2015 to December 2020) was used to identify men receiving their first MRI and MRI/TRUS fusion biopsy for suspected PCa. Clinical, MRI and biopsy data were stratified by radiologist and urologist to evaluate variation in Prostate Imaging-Reporting and Data System (PI-RADS) grading, lesion number and cancer detection. Multivariable logistic regression (MVR) models and area under the curve (AUC) comparisons assessed the relative impact of individual radiologists and urologists. Results: A total of 865 patients (469 biopsy-naïve) were included across 5 urologists and 10 radiologists. Radiologists varied with grading 15.4% to 44.8% of patients with MRI lesions as PI-RADS 3. PCa detection varied significantly by radiologist, from 34.5% to 66.7% (p = 0.003) for PCa and 17.2% to 50% (p = 0.001) for csPCa. Urologists' PCa diagnosis rates varied between 29.2% and 55.8% (p = 0.013) and between 24.6% and 39.8% (p = 0.36) for csPCa. After adjustment for case-mix on MVR, a fourfold to fivefold difference in PCa detection was observed between the highest-performing and lowest-performing radiologist (OR 0.22, 95%CI 0.10-0.47, p < 0.001). MVR demonstrated improved AUC for any PCa and csPCa detection when controlling for radiologist variation (p = 0.017 and p = 0.038), but controlling for urologist was not significant (p = 0.22 and p = 0.086). Any PCa detection (OR 1.64, 95%CI 1.06-2.55, p = 0.03) and csPCa detection (OR 1.57, 95%CI 1.00-2.48, p = 0.05) improved over time (2018-2020 vs. 2015-2017). Conclusions: Variability among radiologists in PI-RADS grading is a key area for quality improvement significantly impacting the detection of PCa and csPCa. Variability for performance of MRI-TRUS fusion prostate biopsies exists by urologist but with less impact on overall detection of csPCa.

Incidental Discovery of Hepatocellular Carcinoma on 18F-PSMA PET CT Performed for Prostate Cancer Reassessment.

Prostate-specific membrane antigen positron emission tomography (PSMA PET) has been approved by the Food and Drug Administration (FDA) to identify prostate cancer in the setting of biochemical recurrence but can also identify other malignancies. 18F-PSMA PET has not been studied as a potential tool for hepatocellular carcinoma (HCC). We describe the case of a 76-year-old male with a rising prostate-specific antigen (PSA) after definitive prostate cancer treatment and no prior liver pathology who was incidentally found to have HCC on 18F-PSMA PET.