Assessment of high-grade prostate cancer risk using prostate cancer biomarkers.

INTRODUCTION: To identify patients at risk of high-grade prostate cancer using prostate cancer biomarkers. MATERIALS AND METHODS: A total of 601 men were screened for prostate cancer in 2012, 2015, and 2016 using prostate cancer biomarkers: prostate health index (phi), 4KScore, and SelectMDx. The first two are blood tests that incorporate several PSA isoforms; SelectMDx measures mRNA levels of homeobox C6 and distal-less homeobox 1 in post-digital rectal examination urine samples. The performance of each biomarker was evaluated using cut off values based on published literature. Gleason Grade Group (GG) ≥ 2 is considered as high-grade prostate cancer. RESULTS: For patients with PSA < 1.5 ng/mL, none were at risk for GG ≥ 2 cancer based on SelectMDx > 0%, whereas 17.1% were at intermediate to high risk of finding GG ≥ 2 cancer with 4KScore ≥ 7.5%, and 3.5% were at risk of finding any prostate cancer with phi ≥ 36 at biopsy. For cut offs revised for finding men at high risk for GG ≥ 2 cancer at biopsy, only one patient with PSA < 1.5 ng/mL would be at risk with 4KScore ≥ 20% and none with phi ≥ 52.7. For patients with PSA 1.5 to 3.99 ng/mL, 2%, 8%, and 1% were at high risk for finding GG ≥ 2 cancer at biopsy based on phi, 4KScore, and SelectMDx, respectively. CONCLUSIONS: Men with PSA < 1.5 ng/mL are at very low risk of finding high-grade prostate cancer at biopsy. However, some men with PSA between 1.5 to 3.99 ng/mL may be at intermediate to high risk for high-grade prostate cancer. Thus, primary care physicians could run biomarkers test and refer those with positive biomarker results to a specialist for further evaluation.

The Ratio of the Number of Biopsy Specimens to Prostate Volume (Biopsy Density) Greater Than 1.5 Improves the Prostate Cancer Detection Rate in Men Undergoing Transperineal Biopsy of the Prostate.

PURPOSE: We sought to determine the minimum number of transperineal prostate mapping biopsies needed to optimize the prostate cancer detection rate. MATERIALS AND METHODS: A total of 436 men underwent transperineal prostate mapping biopsy at 2 institutions. Biopsy density was calculated as the ratio of the total number of specimens retrieved (mean 59.4) to prostate volume (mean 44.9 cc). Associations of biopsy density with prostate specific antigen, prostate specific antigen density, cancer diagnosis and the Gleason score were tested by ANOVA and the chi-square test. Regression analysis was done to determine factors associated with a positive transperineal prostate mapping biopsy and Gleason score 7 or higher cancer. RESULTS: Transperineal prostate mapping biopsy was positive in 299 of 436 men (68.6%). The mean number of positive cores was 7.1 (range 1 to 41) and mean biopsy density was 1.46 (range 0.39 to 3.67). The mean number of cores in positive vs negative transperineal prostate mapping biopsies was 1.61 vs 1.14 (p <0.001). Biopsy density cut points of 0.5 or less, greater than 0.5 to 1.0, greater than 1.0 to 1.5 and greater than 1.5 were associated with positive biopsy in 25%, 37.4%, 70.7% and 84.9% of patients (p <0.001). Dichotomizing biopsy density to 1.5 or less vs greater than 1.5 resulted in a positive biopsy rate of 56.4% vs 84.9% (OR 1.5, 95% CI 1.3-1.7, p <0.001). More Gleason score 6 cancers were diagnosed with higher biopsy density (94 of 158 or 59.5% vs 62 of 141 or 44.9%, p = 0.007). However, the number of positive cores with Gleason score 6 was greater in men with higher biopsy density at 4.9 vs 3.6 (p = 0.036). Prostate specific antigen (p = 0.053) and biopsy density (p = 0.012) were significant on regression analysis for positive transperineal prostate mapping biopsy and Gleason score 7+ disease. CONCLUSIONS: Biopsy density greater than 1.5 increases the diagnosis of prostate cancer by 1.5 times, detects higher volume Gleason score 6 disease and should be considered the optimal sampling approach when performing transperineal prostate mapping biopsy.

The effect of digital rectal exam on the 4Kscore for aggressive prostate cancer.

BACKGROUND: The 4Kscore is a new commercially available blood-based diagnostic test which predicts risk for aggressive, clinically significant prostate cancer on prostate biopsy. The 4Kscore is currently restricted to patients who have not had a digital rectal exam (DRE) in the previous 96 h, owing to prior mixed data suggesting that prostate specific antigen (PSA) isoforms may increase by a statistically significant-if not necessarily clinically significant-amount shortly after DRE. Our primary objective was to determine if 4Kscore test results are affected by a preceding DRE. METHODS: Participants at a Prostate Cancer Awareness Week screening event sponsored by the Prostate Conditions Education Council filled out clinical history questionnaires and had blood samples for 4Kscore testing drawn prior to DRE, then 15-45 min following DRE. Patients with prior cancer diagnosis, 5-alpha reductase inhibitor medication use, or lower urinary tract procedures in the prior 6 months were excluded, resulting in a population of 162 participants for analysis. Values were then compared to determine if there was a significant difference in 4Kscore following DRE. RESULTS: A statistically significant increase was seen in levels of 3 kallikreins measured (total PSA, free PSA, and intact PSA; median <0.03 ng/mL for all). This resulted in a small but statistically significant decrease in post-DRE 4Kscore (median absolute score decrease 0.43%). Using a 4Kscore cutoff of 7.5% resulted in reclassification of 10 patients (6.2%), nine of whom were "downgraded" from above the cutoff to below. CONCLUSIONS: If the blood draw for the 4 K score is performed after a screening DRE, there is a statistically significant difference in the 4 K score results, but in the vast majority of cases it would not affect clinical decision making.

Multi-parametric MRI findings of transitional zone prostate cancers: correlation with 3-dimensional transperineal mapping biopsy.

PURPOSE: A preliminary project to correlate MR findings with mapping prostate biopsy to help differentiate malignant transitional zone lesions form benign prostatic hyperplasia (BPH) nodules. MATERIALS AND METHODS: Institutional IRB approved retrospective study with 14 patients suspected of having prostate cancer who underwent both prostate 3T MRI using endorectal coil and 3D transperineal mapping prostate biopsy. MR exams were independently reviewed by two abdominal radiologists blinded to pathology with disagreement resolved by consensus. An MRI lesion was defined as having hypointense T2 signal subjectively without corresponding T1 high signal intensity and low signal on ADC maps in the central gland. Mapping biopsy consisted of systematic transperineal US guided biopsy with 55-108 cores per patient. RESULTS: Twenty-nine lesions were detected on MRI. Of these, 13 correlated with Gleason 6 or higher biopsy samples. 16 were biopsy negative. Among the various MRI characteristics assessed, lack of T2 hypointense rim demonstrated the highest specificity (93%) and positive predictive value (89%). Highest sensitivity (85%) and negative predictive value (78%) were seen with ill-defined nodules. When suspicious MR characteristics were combined, the specificity and PPV rose to 100% while sensitivity decreased to 45% and NPV decreased to 73%. CONCLUSIONS: Preliminary study indicates MR findings which can help differentiate a BPH nodule from transitional zone prostate cancers which could help direct biopsy in the large and growing number of people suspected of having prostate cancer. Further work will be needed for validation.

Transrectal Ultrasound-guided Versus Transperineal Mapping Prostate Biopsy: Complication Comparison.

Herein, the authors compare morbidity in men who underwent both transrectal ultrasound-guided (TRUS) prostate biopsy and transperineal mapping biopsy (TPMB) at two institutions with extensive experience in both procedures. We also identified strategies and predictive factors to reduce morbidity for both procedures. In our study, 379 men from two institutions, of which 265 (69.9%) had a prior TRUS-guided biopsy, also had TPMB performed via a template with biopsies taken at 5-mm intervals. Men in the TRUS group had a median of 12 cores sampled whereas the TPMB group had 51.5 (range, 16-151). The median biopsy density was 1.1 core/cc prostate volume. Median age and prostate-specific antigen (PSA) level were 65 years (range, 34-86) and 5.5 ng/mL (range, 0.02-118). Of these men, 11 of 265 (4.2%) who had TRUS biopsy developed urinary tract infection compared with 3 of 379 (0.79%) of those with mapping biopsy. Infection was 14.8% in TRUS biopsy group with 13 or more cores versus 2.9% in those with 12 or less (OR, 5.8; 95% CI, 1.6-21.2; P = 0.003). No men developed retention after TRUS biopsy whereas 30 of 379 (7.9%) did following TPMB. Older age, larger prostate volume (PV), and higher core number were associated with retention. On linear regression only age (P = 0.010) and PV (P = 0.016) remained as significant associations. Men older than 65 years had 12.8% versus 3.9% (OR, 3.7; 95% CI, 1.6-8.4, P = 0.001) and PV greater than 42 cc had 13.4% versus 2.7% (OR, 5.7; 95% CI, 2.1-15.1) retention incidence. In the present study TPMB is rarely associated with infection (0.78%) but more commonly with urinary retention (7.9%). Men older than 65 years and with PV greater than 42 cc were at four to five times greater retention risk. Consideration should be given to discharging these men with a urinary catheter following TPMB.

The 3DBiopsy Prostate Biopsy System: Preclinical Investigation of a Needle, Actuator, and Specimen Collection Device Allowing Sampling of Individualized Prostate Lengths Between 20 and 60 mm.

OBJECTIVE: To increase the likelihood of detecting anterior cancers within the prostate and provide a specimen that spans the length of the gland. Newly designed 17- and 15-gauge (G) biopsy needles, a variable actuator, and an integrated pathology system intended for the longer cores were developed and tested for this purpose. MATERIALS AND METHODS: Testing was performed comparing 2 common cannula tip grinds, a Vet-point (sharp tip) and a Menghini-point (atraumatic tip), and were tested against 18-G Bard Monopty in porcine kidney. A variable actuator was developed to fire the needle 20-60 mm and tested in cadaver prostates. RESULTS: The aggregate firings for 3 different shot lengths comparing the Vet- with the Menghini-tip cannulas demonstrated 91% vs 85.2% fill (length of specimen/length of core bed, P = .007). A 15-G trocar needle with the Vet-tip cannula also had the best performance, with an aggregate standard deviation of 6.4% across 3 firing ranges and a minimum to maximum specimen length of 81%-105% of potential fill. Cadaver testing with the Vet-tip needles in the actuator for the transrectal (17-G) and transperineal (15-G) biopsies demonstrated mean fills of 93.3% and 76.5%, respectively. The new transrectal ultrasound needle obtained a 2-fold increase in specimen length over the standard Bard device (P <.001). CONCLUSION: Longer and consistent cores were obtained using the new biopsy needles. Combined with an adjustable actuator, the physician can obtain specimens that include peripheral and anterior zone tissue in 1 core. Determination of cancer location on the longer specimens could enhance focal therapy planning.

Human feasibility study of fluorescence spectroscopy guided optical biopsy needle for prostate cancer diagnosis.

Current prostate biopsy cores have a very low diagnostic yield. These biopsies often fail to diagnose prostate cancer since 90% of cores are histopathologically classified as benign. The concentrations of endogenous fluorophores in prostate tissue vary with disease states. Thus, fluorescence spectroscopy could be utilized to quantify these variations for identification of malignant lesions. We investigated clinical feasibility of a 14 gauge (1.98 mm) optical biopsy needle guided by fluorescence spectroscopy for real-time in vivo prostate cancer diagnosis. Built-in optical sensor has 8×100µm fibers for tissue excitation and a single 200µm fiber to collect spectral data. Custom-made fluorometer has 2 light-emitting diodes at 290 and 340 nm and a spectrometer. User interface for fluorometer operation and data collection was developed using LabView software. Each spectral data acquisition required ~2 seconds. The in vivo biopsies were performed during radical retropubic prostatectomy surgery on the exposed prostate with blood flow to the gland intact. A tissue biopsy core was obtained from each biopsy site after acquisition of spectral data. Above procedure was repeated ex vivo after surgical excision of the prostate. Biopsy cores were histopathologically classified as either benign or malignant and correlated with corresponding spectral data. Partial Least Square analysis was performed to determine diagnostically significant principal components as potential classifiers. A linear support vector machine and leave-one-out cross validation method was employed for tissue classification. Thirteen patients were consented to the study. Histopathological analysis found cancer in 29/208 in vivo and 51/224 ex vivo viable biopsy cores. Study results show 72% sensitivity, 66% specificity, and 93% negative predictive value for in vivo and 75%, 80%, and 93%, respectively, for ex vivo malignant versus benign prostatic tissue classification. Optical biopsy needle has a very high negative predictive value to indicate benign tissue while sufficient sensitivity for targeting areas suspicious for cancer within the prostate gland. Hence, the optical biopsy needle can increase the diagnostic yield of prostate biopsies with consequent improvement in patient care.