RELATIONSHIP BETWEEN SYSTEMATIC BIOPSIES AND HISTOLOGICAL FEATURES OF 222 RADICAL PROSTATECTOMY SPECIMENS: LACK OF PREDICTION OF TUMOR SIGNIFICANCE FOR MEN WITH NONPALPABLE PROSTATE CANCER

Stress testing deep learning models for prostate cancer detection on biopsies and surgical specimens

The presence, location, and extent of prostate cancer is assessed by pathologists using H&E-stained tissue slides. Machine learning approaches can accomplish these tasks for both biopsies and radical prostatectomies. Deep learning approaches using convolutional neural networks (CNNs) have been shown to identify cancer in pathologic slides, some securing regulatory approval for clinical use. However, differences in sample processing can subtly alter the morphology between sample types, making it unclear whether deep learning algorithms will consistently work on both types of slide images. Our goal was to investigate whether morphological differences between sample types affected the performance of biopsy-trained cancer detection CNN models when applied to radical prostatectomies and vice versa using multiple cohorts (N = 1,000). Radical prostatectomies (N = 100) and biopsies (N = 50) were acquired from The University of Pennsylvania to train (80%) and validate (20%) a DenseNet CNN for biopsies (MB), radical prostatectomies (MR), and a combined dataset (MB+R). On a tile level, MB and MR achieved F1 scores greater than 0.88 when applied to their own sample type but less than 0.65 when applied across sample types. On a whole-slide level, models achieved significantly better performance on their own sample type compared to the alternative model (p < 0.05) for all metrics. This was confirmed by external validation using digitized biopsy slide images from a clinical trial [NRG Radiation Therapy Oncology Group (RTOG)] (NRG/RTOG 0521, N = 750) via both qualitative and quantitative analyses (p < 0.05). A comprehensive review of model outputs revealed morphologically driven decision making that adversely affected model performance. MB appeared to be challenged with the analysis of open gland structures, whereas MR appeared to be challenged with closed gland structures, indicating potential morphological variation between the training sets. These findings suggest that differences in morphology and heterogeneity necessitate the need for more tailored, sample-specific (i.e. biopsy and surgical) machine learning models. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Prioritizing precision: detection of prostate cancer using mri guided fusion needle biopsy across the pennsylvania urologic regional collaborative

PURPOSE

Targeted prostate biopsies are increasingly being performed by urologists in the United States including those in the Pennsylvania Urologic Regional Collaborative, a physician-led data-sharing and quality improvement collaborative. To evaluate the performance of MRI guided fusion needle prostate biopsies in the collaborative, we analyzed the variability by practice in rates of detection of clinically significant prostate cancer and patient characteristics associated with detection of clinically significant prostate cancer.

METHODS

We analyzed 857 first-time MRI fusion biopsy procedures performed at five practices (minimum 20 procedures) between 2015 and 2019. We used chi-square analysis for baseline patient characteristics and Grade Group (GG) ≥ 3 tumor detection rates by practice. Multivariable logistic regression was used to estimate the odds of clinically significant cancer detection when adjusting for baseline patient characteristics.

RESULTS

Approximately 15% of men undergoing targeted MRI guided biopsy were ≤ 59 years old. Median prostate specific antigen (PSA) was 6.8 ng/ml. Detection rates for GG ≥ 3 tumors ranged from 14.3% to 28.3% (P = 0.02) across practices. However, the odds of GG ≥ 3 tumor detection did not differ significantly between practices after adjusting for clinical and radiographic factors. Overall, increased likelihood of detecting a GG ≥ 3 tumor was associated with increased age, DRE abnormalities, higher PSA, smaller gland volume and PI-RADS ≥ 4 MRI lesions. There was an 81% concordance rate between PI-RADS ≥ 4 and Gleason grade ≥ 3 prostate cancer.

CONCLUSION

We demonstrate the value of obtaining pre-biopsy MRI given high concordance between presence of suspicious lesions and MRI-targeted biopsy detection of clinically significant prostate cancer. Variability of baseline patient characteristics among practices may account for the observed differences in clinically significant cancer detection rates. These findings can aid standardization and quality improvement efforts within the collaborative.

The predictive value of machine learning and nomograms for lymph node metastasis of prostate cancer: a systematic review and meta-analysis

BACKGROUND

In clinical practice, there are currently a variety of nomograms for predicting lymph node metastasis (LNM) of prostate cancer. At the same time, some scholars have introduced machine learning (ML) into the prediction of LNM of prostate cancer. However, the predictive value of nomograms and ML remains controversial. Based on this situation, this systematic review and meta-analysis was performed to explore the predictive value of various nomograms currently recommended and newly-developed ML models for LNM in prostate cancer patients.

EVIDENCE ACQUISITION

Cochrane, PubMed, Embase, and Web of Science were searched up to November 1, 2022. The risk of bias in the included studies was evaluated using the Prediction model Risk of Bias Assessment Tool (PROBAST). The concordance index (C-index), sensitivity, and specificity were adopted to evaluate the predictive accuracy of the models.

RESULTS

Thirty-one studies (18,803 patients) were included. Seven kinds of nomograms currently recommended, dominated by Briganti nomogram or MSKCC nomogram, were covered in the included studies. For newly-developed ML models, the C-index for LNM prediction in the training set and validation set was 0.846 [95%CI (0.818, 0.873)] and 0.862 [95%CI (0.819-0.905)] respectively. Most ML models in the training set were based on Logistic Regression (LR), which had a sensitivity of 0.78 [95%CI (0.70, 0.85)] and a specificity of 0.85 [95%CI (0.77, 0.90)] in the training set, and a sensitivity of 0.81 [95%CI (0.67, 0.89)] and a specificity of 0.82 [95%CI (0.75, 0.88)] in the validation set. For the recommended nomograms, the C-index in the validation set was 0.745 [95%CI (0.701, 0.790)] for the Briganti nomogram and 0.714 [95%CI (0.662, 0.765)] for the MSKCC nomogram.

CONCLUSION

The predictive accuracy of ML is superior to existing clinically recommended nomograms, and appropriate updates can be conducted to existing nomograms according to special situations.

Canadian Association of Radiologists Prostate MRI White Paper

Prostate cancer is the most common malignancy and the third most common cause of death in Canadian men. In light of evolving diagnostic pathways for prostate cancer and the increased use of MRI, which now includes its use in men prior to biopsy, the Canadian Association of Radiologists established a Prostate MRI Working Group to produce a white paper to provide recommendations on establishing and maintaining a Prostate MRI Programme in the context of the Canadian healthcare system. The recommendations, which are based on available scientific evidence and/or expert consensus, are intended to maintain quality in image acquisition, interpretation, reporting and targeted biopsy to ensure optimal patient care. The paper covers technique, reporting, quality assurance and targeted biopsy considerations and includes appendices detailing suggested reporting templates, quality assessment tools and sample image acquisition protocols relevant to the Canadian healthcare context.

Extracellular Vesicle Proteome in Prostate Cancer: A Comparative Analysis of Mass Spectrometry Studies

Molecular diagnostics based on discovery research holds the promise of improving screening methods for prostate cancer (PCa). Furthermore, the congregated information prompts the question whether the urinary extracellular vesicles (uEV) proteome has been thoroughly explored, especially at the proteome level. In fact, most extracellular vesicles (EV) based biomarker studies have mainly targeted plasma or serum. Therefore, in this study, we aim to inquire about possible strategies for urinary biomarker discovery particularly focused on the proteome of urine EVs. Proteomics data deposited in the PRIDE archive were reanalyzed to target identifications of potential PCa markers. Network analysis of the markers proposed by different prostate cancer studies revealed moderate overlap. The recent throughput improvements in mass spectrometry together with the network analysis performed in this study, suggest that a larger standardized cohort may provide potential biomarkers that are able to fully characterize the heterogeneity of PCa. According to our analysis PCa studies based on urinary EV proteome presents higher protein coverage compared to plasma, plasma EV, and voided urine proteome. This together with a direct interaction of the prostate gland and urethra makes uEVs an attractive option for protein biomarker studies. In addition, urinary proteome based PCa studies must also evaluate samples from bladder and renal cancers to assess specificity for PCa.

Proteomic discovery of non-invasive biomarkers of localized prostate cancer using mass spectrometry

Prostate cancer is the second most frequently diagnosed non-skin cancer in men worldwide. Patient outcomes are remarkably heterogeneous and the best existing clinical prognostic tools such as International Society of Urological Pathology Grade Group, pretreatment serum PSA concentration and T-category, do not accurately predict disease outcome for individual patients. Thus, patients newly diagnosed with prostate cancer are often overtreated or undertreated, reducing quality of life and increasing disease-specific mortality. Biomarkers that can improve the risk stratification of these patients are, therefore, urgently needed. The ideal biomarker in this setting will be non-invasive and affordable, enabling longitudinal evaluation of disease status. Prostatic secretions, urine and blood can be sources of biomarker discovery, validation and clinical implementation, and mass spectrometry can be used to detect and quantify proteins in these fluids. Protein biomarkers currently in use for diagnosis, prognosis and relapse-monitoring of localized prostate cancer in fluids remain centred around PSA and its variants, and opportunities exist for clinically validating novel and complimentary candidate protein biomarkers and deploying them into the clinic.

MRI-Targeted Prostate Biopsy Techniques: AJR Expert Panel Narrative Review

Prostate cancer is the second most common malignancy in men worldwide. Systematic transrectal prostate biopsy is commonly used to obtain tissue to establish the diagnosis. However, in recent years, MRI-targeted biopsy (based on an MRI examination performed prior to consideration of biopsy) has been shown to detect more clinically significant cancer and less clinically insignificant cancer compared to systematic biopsy. This approach of performing MRI prior to biopsy has become, or is becoming, a standard of practice in centers throughout the world. This growing use of an MRI-directed pathway is leading to performance of a larger volume of MRI-targeted prostate biopsies. The three common MRI-targeted biopsy techniques are cognitive biopsy, MRI-ultrasound software fusion biopsy, and MRI in-bore guided biopsy. These techniques for using MRI information at the time of biopsy can be performed via a transrectal or transperineal approach. This narrative review presents the three MRI-targeted biopsy techniques along with their advantages and shortcomings. Comparisons among the techniques are summarized based on the available evidence. Studies to date have provided heterogeneous results, and the preferred technique remains debated.

Techniques and Outcomes of MRI-TRUS Fusion Prostate Biopsy

PURPOSE OF REVIEW

The goal of this study is to review recent findings and evaluate the utility of MRI transrectal ultrasound fusion biopsy (FBx) techniques and discuss future directions.

RECENT FINDINGS

FBx detects significantly higher rates of clinically significant prostate cancer (csPCa) than ultrasound-guided systematic prostate biopsy (SBx), particularly in repeat biopsy settings. FBx has also been shown to detect significantly lower rates of clinically insignificant prostate cancer. In addition, a dedicated prostate MRI can assist in more accurately predicting the Gleason score and provide further information regarding the index cancer location, prostate volume, and clinical stage. The ability to accurately evaluate specific lesions is vital to both focal therapy and active surveillance, for treatment selection, planning, and adequate follow-up. FBx has been demonstrated in multiple high-quality studies to have improved performance in diagnosis of csPCa compared to SBx. The combination of FBx with novel technologies including radiomics, prostate-specific membrane antigen positron emission tomography (PSMA PET), and high-resolution micro-ultrasound may have the potential to further enhance this performance.

Prospective Evaluation of PI-RADS Version 2.1 for Prostate Cancer Detection

OBJECTIVE. The purpose of this study was to prospectively evaluate Prostate Imaging Reporting and Data and System version 2.1 (PI-RADSv2.1), which was released in March 2019 to update version 2.0, for prostate cancer detection with transrectal ultrasound-MRI fusion biopsy and 12-core systematic biopsy. SUBJECTS AND METHODS. This prospective study included 110 consecutively registered patients who underwent multiparametric MRI evaluated with PI-RADSv2.1 criteria followed by fusion biopsy and systematic biopsy between April and September 2019. Lesion-based cancer detection rates (CDRs) were calculated for prostate cancer (Gleason grade group, > 0) and clinically significant prostate cancer (Gleason grade group, > 1). RESULTS. A total of 171 lesions (median size, 1.1 cm) in 110 patients were detected and evaluated with PI-RADSv2.1. In 16 patients no lesion was detected, and only systematic biopsy was performed. Lesions were categorized as follows: PI-RADS category 1, 1 lesion; PI-RADS category 2, 34 lesions; PI-RADS category 3, 54 lesions; PI-RADS category 4, 52 lesions; and PI-RADS category 5, 30 lesions. Histopathologic analysis revealed prostate cancer in 74 of 171 (43.3%) lesions and clinically significant prostate cancer in 57 of 171 (33.3%) lesions. The CDRs of prostate cancer for PI-RADS 2, 3, 4, and 5 lesions were 20.0%, 24.1%, 51.9%, and 90.0%. The CDRs of clinically significant prostate cancer for PI-RADS 1, 2, 3, 4, and 5 lesions were 0%, 5.7%, 14.8%, 44.2%, and 80.0%. In 16 patients with normal multiparametric MRI findings (PI-RADS 1), the CDRs were 50.0% for PCa and 18.8% for clinically significant prostate cancer. CONCLUSION. This investigation yielded CDRs assessed with prospectively assigned PI-RADSv2.1 scores. CDRs increased with higher PI-RADSv2.1 scores. These results can be compared with previously published outcomes derived with PI-RADS version 2.0.

Biparametric MRI prior to Radical Radiation Therapy for Prostate Cancer in a Caribbean Population: Implications for Risk Group Stratification and Treatment

PURPOSE

To assess risk-group migration and subsequent management change following biparametric MRI using a risk-stratified approach in a group of Caribbean men with prostate adenocarcinoma being offered external beam radiation therapy (EBRT).

MATERIALS AND METHODS

This retrospective study assessed the biparametric MRI findings in men who opted for EBRT from January 2018 to June 2019 (n = 79; mean age, 67.9 years ± 6.2 [standard deviation]). Serum prostate-specific antigen level, digital rectal examination findings, histologic grade group (GG) from transrectal US-guided biopsy, prior androgen deprivation therapy (ADT), and any prior CT results were used to stratify patients into low-, intermediate-, and high-risk groups, according to the National Comprehensive Cancer Network risk categories. Risk-group stratification prior to MRI separated patients into low- (seven of 79 [8.9%]), intermediate- (36 of 79 [45.6%]) and high-risk (36 of 79 [45.6%]) groups. Following MRI, any risk group (low, intermediate, high, nodal involvement, and metastatic disease) or oncologic management changes were recorded. Multivariable binary logistic regression analyses were used to assess predictor of upgrade status, with adjustment for demographic covariates jointly.

RESULTS

Following MRI, 30 of 79 (38.0%) patients had risk-group upshifts compared with their original assessment. Patients were recategorized into low risk (one of 79, 1.3%), intermediate risk (19 of 79, 24.1%), high risk (51 of 79, 64.6%), nodal involvement (one of 79, 1.3%), and metastatic disease (seven of 79, 8.9%). From the original groupings, there were six of seven (85.7%) from the low group, 18 of 36 (50.0%) from the intermediate group, and six of 36 (16.7%) from the high group that had risk group upward shifts. There was no association with GG: GG2 versus GG1, P = .53; GG3 versus GG1, P = .98; or prior ADT (P = .37) and the adjusted odds of risk-group upshifts. MRI findings resulted in treatment plan modification for 39 of 79 (49.4%) men overall.

CONCLUSION

Prostate MRI should be considered for patients in high-risk populations prior to EBRT because upstaging from MR image assessment may have implications for modification of treatment.Keywords: MR-Imaging, Prostate, Radiation Therapy© RSNA, 2020See the commentary by Davenport and Shankar in this issue.

Histogram analysis from stretched exponential model on diffusion-weighted imaging: evaluation of clinically significant prostate cancer

OBJECTIVE

To evaluate the usefulness of histogram analysis of stretched exponential model (SEM) on diffusion-weighted imaging in evaluating clinically significant prostate cancer (CSC).

METHODS

A total of 85 patients with prostate cancer underwent 3 T multiparametric MRI, followed by radical prostatectomy. Histogram parameters of the tumor from the SEM [distributed diffusion coefficient (DDC) and α] and the monoexponential model [MEM; apparent diffusion coefficient (ADC)] were evaluated. The associations between parameters and Gleason score or Prostate Imaging Reporting and Data System v. 2 were evaluated. The area under the receiver operating characteristics curve was calculated to evaluate diagnostic performance of parameters in predicting CSC.

RESULTS

The values of histogram parameters of DDC and ADC were significantly lower in patients with CSC than in patients without CSC (p < 0.05), except for skewness and kurtosis. The value of the 25th percentile of α was significantly lower in patients with CSC than in patients without CSC (p = 0.014). Histogram parameters of ADC and DDC had significant weak to moderate negative associations with Gleason score or Prostate Imaging Reporting and Data System v. 2 (p < 0.001), except for skewness and kurtosis. For predicting CSC, the area under the curves of mean ADC (0.856), 50th percentile DDC (0.852), and 25th percentile α (0.707) yielded the highest values compared to other histogram parameters from each group.

CONCLUSION

Histogram analysis of the SEM on diffusion-weighted imaging may be a useful quantitative tool for evaluating CSC. However, the SEM did not outperform the MEM.

ADVANCES IN KNOWLEDGE

Histogram parameters of SEM may be useful for evaluating CSC.

Comparison of Tumor Volume Parameters on Prostate Cancer Biopsies

CONTEXT.—

Prostate biopsy reports require an indication of prostate cancer volume. No consensus exists on the methodology of tumor volume reporting.

OBJECTIVE.—

To compare the prognostic value of different biopsy prostate cancer volume parameters.

DESIGN.—

Prostate biopsies of the European Randomized Study of Screening for Prostate Cancer were reviewed (n = 1031). Tumor volume was quantified in 6 ways: average estimated tumor percentage, measured total tumor length, average calculated tumor percentage, greatest tumor length, greatest tumor percentage, and average tumor percentage of all biopsies. Their prognostic value was determined by using either logistic regression for extraprostatic expansion (EPE) and surgical margin status after radical prostatectomy (RP), or Cox regression for biochemical recurrence-free survival (BCRFS) and disease-specific survival (DSS) after RP (n = 406) and radiation therapy (RT) (n = 508).

RESULTS.—

All tumor volume parameters were significantly mutually correlated (R2 > 0.500, P < .001). None were predictive for EPE, surgical margin, or BCRFS after RP in multivariable analysis, including age, prostate-specific antigen, number of positive biopsies, and grade group. In contrast, all tumor volume parameters were significant predictors for BCRFS (all P < .05) and DSS (all P < .05) after RT, except greatest tumor length. In multivariable analysis including only all tumor volume parameters as covariates, calculated tumor length was the only predictor for EPE after RP (P = .02) and DSS after RT (P = .02).

CONCLUSIONS.—

All tumor volume parameters had comparable prognostic value and could be used in clinical practice. If tumor volume quantification is a threshold for treatment decision, calculated tumor length seems preferential, slightly outperforming the other parameters.

Photoacoustic tomography for imaging the prostate: a transurethral illumination probe design and application

In vivo imaging of prostate cancer with photoacoustic tomography is currently limited by the lack of sufficient local fluence for deep tissue penetration and the risk of over-irradiation near the laser-tissue contact surface. We propose the design of a transurethral illumination probe that addresses those limitations. A high energy of 50 mJ/pulse is coupled into a 1000-µm-core diameter multimode fiber. A 2 cm diffusing end is fabricated, which delivers light in radial illumination. The radial illumination is then reflected and reshaped by a parabolic cylindrical mirror to obtain nearly parallel side illumination with a doubled fluence. The fiber assembly is housed in a 25 Fr cystoscope sheath to provide protection of the fiber and maintain a minimal laser-tissue contact distance of 5 mm. A large laser-tissue contact surface area of 4 cm² is obtained and the fluence on the tissue surface is kept below the maximum permissible exposure. By imaging a prostate mimicking phantom, a penetration depth of 3.5 cm at 10 mJ/cm² fluence and 700 nm wavelength is demonstrated. The results indicate that photoacoustic tomography with the proposed transurethral probe has the potential to image the entire prostate while satisfying the fluence maximum permissible exposure and delivering a high power to the tissue.

The Current State of MR Imaging-targeted Biopsy Techniques for Detection of Prostate Cancer

Systematic transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations because of its inability to accurately visualize and target prostate lesions. Multiparametric magnetic resonance (MR) imaging of the prostate is more reliably able to localize significant prostate cancer. Targeted prostate biopsy by using MR imaging may thus help to reduce false-negative results and improve risk assessment. Several commercial devices are now available for targeted prostate biopsy, including in-gantry MR imaging-targeted biopsy and real-time transrectal US-MR imaging fusion biopsy systems. This article reviews the current status of MR imaging-targeted biopsy platforms, including technical considerations, as well as advantages and challenges of each technique. ^© RSNA, 2017.

Multiparametric MR Imaging for Detection and Locoregional Staging of Prostate Cancer

Detection and staging of prostate cancer (PCa) based on digital rectal examination, prostate-specific antigen levels, and systematic transrectal ultrasound-guided biopsies show notorious limitations in light of the current needs of PCa management. Multiparametric magnetic resonance imaging (mpMRI) has emerged as a useful noninvasive imaging technique for detection, staging, assessment of aggressiveness, and treatment monitoring of PCa, combining anatomic high-resolution T2-weighted images with functional techniques, such as diffusion-weighted imaging and dynamic contrast enhancement evaluation. In this article, the authors review the technical aspects and the current clinical role of mpMRI for detection and locoregional staging of PCa.

Prostate Imaging Reporting and Data System, Version 2, Assessment Categories and Pathologic Outcomes in Patients With Gleason Score 3 + 4 = 7 Prostate Cancer Diagnosed at Biopsy

OBJECTIVE

The purpose of this study is to assess associations between Prostate Imaging Reporting and Data System, version 2 (PI-RADSv2), categories and the presence of a tumor with a Gleason score (GS) of 4 + 3 = 7 or greater or the presence of extraprostatic extension (EPE) at radical prostatectomy (RP) in patients with a GS 3 + 4 = 7 tumor at biopsy.

MATERIALS AND METHODS

A total of 81 men with GS 3 + 4 = 7 prostate cancer diagnosed by transrectal ultrasound-guided biopsy underwent multiparametric MRI and RP between 2012 and 2015. Two blinded radiologists assessed multiparametric MR images and assigned PI-RADSv2 assessment categories (categories 1-5) with the use of sector maps, which were compared with regard to the location of the tumor, the GS, and the presence of EPE at RP. Comparisons were performed between groups with the use of chi-square and multivariate analysis. Diagnostic accuracy was assessed using ROC curve analysis, and localization was compared using the Fisher exact test.

RESULTS

A total of 53.1% of men (43/81) had EPE, and 21.0% (17/81) had GS 4 + 3 = 7 prostate cancer after RP, whereas 2.5% of men (2/81) had their tumors downgraded to GS 3 + 3 = 6. No statistically significant difference in patient age, prostate specific antigen level, or clinical stage existed between groups (p > 0.05). PI-RADSv2 assessment categories were significantly higher for GS 4 + 3 = 7 tumors (p = 0.03). PI-RADSv2 showed moderate accuracy for the diagnosis of GS 4 + 3 = 7 tumors (AUC, 0.65; 95% CI, 0.54-0.77), with a category of 4 or higher having a sensitivity and specificity for diagnosis of 94.1% and 23.4%, respectively. No patient with a PI-RADSv2 category lower than 3 had a GS 4 + 3 = 7 tumor. Accuracy of tumor localization ranged from 86.4% to 92.6%, with 88.2% of errors (15/17) occurring in GS 3 + 3 = 6 or GS 3 + 4 = 7 tumors (p = 0.30). PI-RADSv2 categories were noted to be higher when EPE was present (p < 0.001). Interobserver agreement was moderate (κ = 0.43).

CONCLUSION

For GS 3 + 4 = 7 cancers detected at transrectal ultrasound-guided biopsy, higher PI-RADSv2 assessment categories are associated with upgrading to GS 4 + 3 = 7 cancer and with the presence of EPE after RP. A PI-RADSv2 score of 3 or higher was 100% sensitive for diagnosing GS 4 + 3 = 7 tumors.

Correlation of Periacinar Retraction Clefting in Needle Core Biopsies and Corresponding Prostatectomy Specimens of Patients with Prostatic Adenocarcinoma

One of the underemphasized supportive criteria for the diagnosis of prostatic cancer is the presence of retraction clefting around neoplastic glands. We analyzed a series of 152 prostatic cancer cases to determine the frequency, extent, and correlation of periacinar retraction clefting between needle core biopsies (NCB) and corresponding matched radical prostatectomy (RP) specimens. Clefting was significantly more frequent in neoplastic compared to nonneoplastic acini in NBC and RP (p<0.05). There was no significant difference in the frequency of retraction clefting in neoplastic acini between NCB and corresponding RP (p>O.05). We have also found a concordance in matched RP and NCB (Kappa=0.582). We conclude that periacinar retraction clefting appears more frequently in neoplastic acini and could serve as a reliable criterion in the diagnosis of prostatic adenocarcinoma.

Developing a Correct System to Evaluate the Accuracy of Gleason Score in Prostate Cancer of Chinese Population

INTRODUCTION

A study was conducted to develop a new correct system to improve the overall rate of Gleason sum concordance between biopsy and final pathology.

MATERIALS AND METHODS

A total of 592 consecutive patients who had undergone transrectal ultrasound-guided prostate biopsy and radical prostatectomy were evaluated during the first stage. Age, PSA, PSA density (PSAD), biopsy cores, positive cores, prostate volume, positive core rate (PCR), core volume rate (CVR) and digital rectal examination findings were considered predictive factors. A multiple logistic regression analysis involving a backward elimination selection procedure and linear regression analysis involving a stepwise procedure were applied to select independent predictors.

RESULTS

Positive cores, PCR, CVR and PSAD were included in our assessing credibility model in the first stage. A significantly higher area under the receiver-operating curve was obtained in our model compared with CVR alone (0.641 vs. 0.517). In the second stage, patients with credibility of pre-operative Gleason score <0.388 were subjected to further evaluation. Compared with the 2 statuses, the rate of overall concordance was significantly increased (60.3 vs. 50.2%, p = 0.002).

CONCLUSIONS

We developed a follow-up strategy based on the new and correct system, which represents an important consideration procedure when clinicians make decisions with regard to treatment plans.

Whole-Tumor Quantitative Apparent Diffusion Coefficient Histogram and Texture Analysis to Predict Gleason Score Upgrading in Intermediate-Risk 3 + 4 = 7 Prostate Cancer

OBJECTIVE

The objective of our study was to evaluate whole-lesion quantitative apparent diffusion coefficient (ADC) for the prediction of Gleason score (GS) upgrading in 3 + 4 = 7 prostate cancer.

MATERIALS AND METHODS

Fifty-four patients with GS 3 + 4 = 7 prostate cancer diagnosed at systematic transrectal ultrasound (TRUS)-guided biopsy underwent 3-T MRI and radical prostatectomy (RP) between 2012 and 2014. A blinded radiologist contoured dominant tumors on ADC maps using histopathologic correlation. The whole-lesion mean ADC, ADC ratio (normalized to peripheral zone), ADC histogram, and texture analysis were compared between tumors with GS upgrading and those without GS upgrading using multivariate ROC analyses and logistic regression modeling.

RESULTS

Tumors were upgraded to GS 4 + 3 = 7 after RP in 26% (n = 14) of the 54 patients, and tumors were downgraded after RP in none of the patients. The mean ADC, ADC ratio, 10th-centile ADC, 25th-centile ADC, and 50th-centile ADC were similar between patients with GS 3 + 4 = 7 tumors (0.99 ± 0.22, 0.58 ± 0.15, 0.77 ± 0.31, 0.94 ± 0.28, and 1.15 ± 0.24, respectively) and patients with upgraded GS 4 + 3 = 7 tumors (1.02 ± 0.18, 0.55 ± 0.11, 0.71 ± 0.26, 0.89 ± 0.20, and 1.11 ± 0.16) (p > 0.05). Regression models combining texture features improved the prediction of GS upgrading. The combination of kurtosis, entropy, and skewness yielded an AUC of 0.76 (SE = 0.07) (p < 0.001), a sensitivity of 71%, and a specificity of 73%. The combination of kurtosis, heterogeneity, entropy, and skewness yielded an AUC of 0.77 (SE = 0.07) (p < 0.001), a sensitivity of 71%, and a specificity of 78%.

CONCLUSION

In this study, whole-lesion mean ADC, ADC ratio, and ADC histogram analysis were not predictive of pathologic upgrading of GS 3 + 4 = 7 prostate cancer after RP. ADC texture analysis improved accuracy.

Role of Magnetic Resonance Imaging in Prostate Cancer Screening: A Pilot Study Within the Göteborg Randomised Screening Trial

BACKGROUND

Magnetic resonance imaging (MRI) and targeted biopsies (TB) have shown potential to more accurately detect significant prostate cancer compared with prostate-specific antigen (PSA) and systematic biopsies (SB).

OBJECTIVE

To compare sequential screening (PSA+MRI) with conventional PSA screening.

DESIGN, SETTING, AND PARTICIPANTS

Of 384 attendees in the 10th screening round of the Göteborg randomised screening trial, 124 men, median age 69.5 yr, had a PSA of ≥ 1.8 ng/ml and underwent a prebiopsy MRI. Men with suspicious lesions on MRI and/or PSA ≥ 3.0ng/ml were referred for biopsy. SB was performed blinded to MRI results and TB was performed in men with tumour-suspicious findings on MRI. Three screening strategies were compared (PSA ≥ 3.0+SB; PSA ≥ 3.0+MRI+TB and PSA ≥ 1.8+MRI+TB).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cancer detection rates, sensitivity, and specificity were calculated per screening strategy and compared using McNemar's test.

RESULTS AND LIMITATIONS

In total, 28 cases of prostate cancer were detected, of which 20 were diagnosed in biopsy-naïve men. Both PSA ≥ 3.0+MRI and PSA ≥ 1.8+MRI significantly increased specificity compared with PSA ≥ 3.0+SB (0.92 and 0.79 vs 0.52; p<0.002 for both), while sensitivity was significantly higher for PSA ≥ 1.8+MRI compared with PSA ≥ 3.0+MRI (0.73 vs 0.46, p=0.008). The detection rate of significant cancer was higher with PSA ≥ 1.8+MRI compared with PSA ≥ 3.0+SB (5.9% vs 4.0%), while the detection rate of insignificant cancer was lowered by PSA ≥ 3.0+MRI (0.3% vs 1.2%). The primary limitation of this study is the small sample of men.

CONCLUSION

A screening strategy with a lowered PSA cut-off followed by TB in MRI-positive men seems to increase the detection of significant cancers while improving specificity. If replicated, these results may contribute to a paradigm shift in future screening.

PATIENT SUMMARY

Major concerns in prostate-specific antigen screening are overdiagnosis and underdiagnosis. We evaluated whether prostate magnetic resonance imaging could improve the balance of benefits to harm in prostate cancer screening screening, and we found a promising potential of using magnetic resonance imaging in addition to prostate-specific antigen.

Small Field-of-view single-shot EPI-DWI of the prostate: Evaluation of spatially-tailored two-dimensional radiofrequency excitation pulses

PURPOSE

Spatially-tailored (RF) excitation pulses in echo-planar imaging (EPI), combined with a decreased FOV in the phase-encoding direction, enable a reduction of k-space acquisition lines, which shortens the echo train length (ETL) and reduces susceptibility artifacts. The purpose of this study was to evaluate the image quality of a zoomed EPI (z-EPI) sequence in diffusion-weighted imaging (DWI) of the prostate in comparison to a conventional single-shot EPI using single-channel (c-EPI1) and multi-channel (c-EPI2) RF excitation, with and without use of an endorectal coil.

MATERIALS AND METHODS

33 consecutive patients (mean age: 61 +/- 9 years; mean PSA: 8.67±6.23 ng/ml) with examinations between 10/2012 and 02/2014 were analyzed in this retrospective study. In 26 of 33 patients the initial multiparametric (mp)-MRI was performed on a whole-body 3T scanner (Magnetom Trio, Siemens, Erlangen, Germany) using an endorectal coil (c (conventional)-EPI1). Zoomed-EPI (Z-EPI) examinations of these patients and a complete mp-MRI protocol including c-EPI2 of 7 additional patients were carried out on another 3T wb MR scanner with two-channel dynamic parallel transmit capability (Magnetom Skyra with TimTX TrueShape, Siemens). For z-EPI, the one-dimensional spatially selective RF excitation pulse was replaced by a two-dimensional RF pulse. Degree of image blur and susceptibility artifacts (0=not present to 3= non-diagnostic), maximum image distortion (mm), apparent diffusion coefficient (ADC) values, as well as overall scan preference were evaluated. SNR maps were generated to compare c-EPI2 and z-EPI.

RESULTS

Overall image quality of z-EPI was preferred by both readers in all examinations with a single exception. Susceptibility artifacts were rated significantly lower on z-EPI compared to both other methods (z-EPI vs c-EPI1: p<0.01; z-EPI vs c-EPI2: p<0.01) as well as image blur (z-EPI vs c-EPI1: p<0.01; z-EPI vs c-EPI2: p<0.01). Image distortion was not statistically significantly reduced with z-EPI (z-EPI vs c-EPI1: p=0.12; z-EPI vs c-EPI2: p=0.42). Interobserver agreement for ratings of susceptibility artifacts, image blur and overall scan preference was good. SNR was higher for z-EPI than for c-EPI1 (n=1).

CONCLUSION

Z-EPI leads to significant improvements in image quality and artifacts as well as image blur reduction improving prostate DWI and enabling accurate fusion with conventional sequences. The improved fusion could lead to advantages in the field of MRI-guided biopsy suspicous lesions and performance of locally ablative procedures for prostate cancer.

False positive and false negative diagnoses of prostate cancer at multi-parametric prostate MRI in active surveillance

Abstract

MP-MRI is a critical component in active surveillance (AS) of prostate cancer (PCa) because of a high negative predictive value for clinically significant tumours. This review illustrates pitfalls of MP-MRI and how to recognise and avoid them. The anterior fibromuscular stroma and central zone are low signal on T2W-MRI/apparent diffusion coefficient (ADC), resembling PCa. Location, progressive enhancement and low signal on b ≥1000 mm²/s echo-planar images (EPI) are differentiating features. BPH can mimic PCa. Glandular BPH shows increased T2W/ADC signal, cystic change and progressive enhancement; however, stromal BPH resembles transition zone (TZ) PCa. A rounded morphology, low T2 signal capsule and posterior/superior location favour stromal BPH. Acute/chronic prostatitis mimics PCa at MP-MRI, with differentiation mainly on clinical grounds. Visual analysis of diffusion-weighted MRI must include EPI and appropriate windowing of ADC. Quantitative ADC analysis is limited by lack of standardization; the ADC ratio and ADC histogram analysis are alternatives to mean values. DCE lacks standardisation and has limited utility in the TZ, where T2W/DWI are favoured. Targeted TRUS-guided biopsies of MR-detected lesions are challenging. Lesions detected on MP-MRI may not be perfectly targeted with TRUS and this must be considered when faced with a suspicious lesion on MP-MRI and a negative targeted TRUS biopsy histopathological result.

Keypoints

• Multi-parametric MRI plays a critical role in prostate cancer active surveillance.

• Low T2W signal intensity structures appear dark on ADC, potentially simulating cancer.

• Stromal BPH mimics cancer at DWI and DCE.

• Long b value trace EPI should be reviewed

• Targeted biopsy of MR-detected lesions using TRUS guidance may be challenging.

Multiparametric magnetic resonance imaging of the prostate: current concepts

Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI). Those functional techniques are related to biological properties of the tumor, so that DWI correlates to cellularity and Gleason scores, DCE correlates to angiogenesis, and MRSI correlates to cell membrane turnover. The combined use of those techniques enhances the diagnostic confidence and allows for better characterization of PCa. The present article reviews and illustrates the technical aspects and clinical applications of each component of mpMR imaging, in a practical approach from the urological standpoint.

Pathological characteristics of low risk prostate cancer based on totally embedded prostatectomy specimens

BACKGROUND

Surveillance and focal therapy are increasingly considered for low risk prostate cancer (PC). We describe pathological characteristics of low risk PC at radical prostatectomy in contemporary patients.

METHODS

Five-hundred-fifty-two men from 2008 to 2012 with low risk (stage T1c/T2a, PSA ≤ 10 ng/ml, Gleason score ≤6) PC underwent radical prostatectomy. Slides were re-reviewed to grade and stage the tumor, map separate tumor nodules, and calculate their volumes.

RESULTS

Ninety-three (16.9%) men had prostatectomy Gleason score 3 + 4 = 7 or higher and were excluded. Five (0.9%) men had no residual carcinoma. Remaining 454 patients composed the study cohort. The median age was 57 years (36-73) and median PSA 4.4 ng/ml (0.4-9.9). Racial distribution was 77.5% Caucasian, 15.5% African American, and 7% other. The median total tumor volume was 0.38 cm(3) (0.003-7.22). Seventy percent of the patients had bilateral tumor and 34% had a tumor nodule >0.5 cm(3) . The index lesion represented 89% (median) of the total tumor volume. Extraprostatic extension and positive margin were present in 5.7% and 9% of cases, respectively. The tumor nodules measuring >0.5 cm(3) were located almost equally between the anterior (53%) and peripheral (47%) gland. The relationship between PSA and total tumor volume was weak (r = 0.13, P = 0.005). The relationship between PSA density and total tumor volume was slightly better (r = 0.26, P < 0.001).

CONCLUSIONS

Low risk prostate cancer is generally a low volume disease. Gleason score upgrade is seen in 16.9% of cases at radical prostatectomy. While the index lesion accounts for the bulk of the disease, the cancer is usually multifocal and bilateral. Neither PSA nor PSA density correlates well with the total tumor volume. Prostate size has a significant contribution to PSA level. These factors need to be considered in treatment planning for low risk prostate cancer.

Computer-Aided Detection and diagnosis for prostate cancer based on mono and multi-parametric MRI: a review

Prostate cancer is the second most diagnosed cancer of men all over the world. In the last few decades, new imaging techniques based on Magnetic Resonance Imaging (MRI) have been developed to improve diagnosis. In practise, diagnosis can be affected by multiple factors such as observer variability and visibility and complexity of the lesions. In this regard, computer-aided detection and computer-aided diagnosis systems have been designed to help radiologists in their clinical practice. Research on computer-aided systems specifically focused for prostate cancer is a young technology and has been part of a dynamic field of research for the last 10 years. This survey aims to provide a comprehensive review of the state-of-the-art in this lapse of time, focusing on the different stages composing the work-flow of a computer-aided system. We also provide a comparison between studies and a discussion about the potential avenues for future research. In addition, this paper presents a new public online dataset which is made available to the research community with the aim of providing a common evaluation framework to overcome some of the current limitations identified in this survey.

Is primary tumor detectable in prostatic carcinoma at routine contrast-enhanced CT?

OBJECTIVES

To determine if prostatic carcinoma (PCa) is detectable at routine contrast-enhanced CT (CECT).

MATERIALS AND METHODS

With institutional review board approval, 63 consecutive PCa patients underwent CECT before therapy. Two blinded radiologists assessed for rounded focal enhancing peripheral zone nodules. Diagnostic accuracy and inter-observer agreement were compared by Gleason Score (GS).

RESULTS

Overall sensitivity was 63-76% with moderate agreement, K=0.42. The false-positive rate was 15%. Sensitivities and agreement for GS 9-10, 7-8 and 6 PCa were 84-91%, 73-84%, 41-71%, (P=.023 and .001) and K=(0.72, 0.69, 0.23).

CONCLUSIONS

CECT has good sensitivity for detecting GS ≥7 PCa with substantial agreement and a low false-positive rate.

Magnetic resonance imaging-guided prostate biopsy: present and future

Systemic transrectal ultrasound-guided biopsy (TRUSBx) is the standard procedure for diagnosing prostate cancer (PCa), but reveals a limited accuracy for the detection of cancer. Currently, multiparametric MR imaging (mp-MRI) is increasingly regarded as a promising method to detect PCa with an excellent positive predictive value. The use of mp-MRI during a MRI-guided biopsy (MRGB) procedure improves the quality of a targeted biopsy. The aim of this article is to provide an overview about the MRGB technique for PCa detection, to review the accuracy and clinical indications of MRGB and discuss its current issues and further directions. A MRGB seems accurate and efficient for the detection of clinically significant PCa in men with previous negative TRUSBx. Moreover, it may decrease the detection of clinically insignificant cancers with fewer biopsy cores.

Modernizing the diagnostic and decision-making pathway for prostate cancer

PSA has led to a drastic increase in the detection of prostate cancer, rendering this biomarker the gateway for the diagnostic pathway of prostatic neoplasms. However, the increase in incidence has not been mirrored by a similar reduction in mortality. Widespread PSA testing has facilitated the overdiagnosis and overtreatment of indolent disease. To reduce this phenomenon and avoid negative repercussions on the quality of life of men undergoing unnecessary therapies, the diagnostic pathway of prostate cancer needs to be improved. Multiparametric MRI (mp-MRI) can enhance the sensitivity and specificity of PSA, as well as the shortcomings of random biopsy sampling. This novel imaging technique has been proven to identify larger and more aggressive cancer foci, which should be targeted for treatment. New technological developments now allow for fusion of mp-MRI images with real-time ultrasound, opening the way to lesion-targeted biopsies. Furthermore, mp-MRI and targeted biopsies can also improve active surveillance protocols and permit more conservative focal therapy strategies. By implementing targeted biopsies, the diagnostic pathway will focus on clinically significant disease, consequently reducing overdiagnosis and overtreatment. Before this novel protocol becomes the new gold standard, mp-MRI acquisition and interpretation need to be standardized and targeted-biopsy strategies need to be further validated prior to abandoning random-sampling ones. Several multidisciplinary consortiums are already working on the standardization of prostate MRI, and there are ongoing prospective trials on targeted biopsies and MRI. Soon, imaging of prostatic lesions and selected biopsies will modify the diagnostic evaluation of prostate cancer, reducing overtreatment and therapy-derived complications that negatively affect quality of life.

Multiparametric MRI in biopsy guidance for prostate cancer: fusion-guided

Prostate cancer (PCa) is the most common solid-organ malignancy among American men and the second most deadly. Current guidelines recommend a 12-core systematic biopsy following the finding of an elevated serum prostate-specific antigen (PSA). However, this strategy fails to detect an unacceptably high percentage of clinically significant cancers, leading researchers to develop new, innovative methods to improve the effectiveness of prostate biopsies. Multiparametric-MRI (MP-MRI) has emerged as a promising instrument in identifying suspicious regions within the prostate that require special attention on subsequent biopsy. Fusion platforms, which incorporate the MP-MRI into the biopsy itself and provide active targets within real-time imaging, have shown encouraging results in improving the detection rate of significant cancer. Broader applications of this technology, including MRI-guided focal therapy for prostate cancer, are in early phase trials.

The role of magnetic resonance imaging in the diagnosis and management of prostate cancer

BACKGROUND

The diagnosis of prostate cancer has long been plagued by the absence of an imaging tool that reliably detects and localises significant tumours. Recent evidence suggests that multi-parametric MRI could improve the accuracy of diagnostic assessment in prostate cancer. This review serves as a background to a recent USANZ position statement. It aims to provide an overview of MRI techniques and to critically review the published literature on the clinical application of MRI in prostate cancer.

TECHNICAL ASPECTS

The combination of anatomical (T2-weighted) MRI with at least two of the three functional MRI parameters - which include diffusion-weighted imaging, dynamic contrast-enhanced imaging and spectroscopy - will detect greater than 90% of significant (moderate to high risk) tumours; however MRI is less reliable at detecting tumours that are small (<0.5 cc), low grade (Gleason score 6) or in the transitional zone. The higher anatomical resolution provided by 3-Tesla magnets and endorectal coils may improve the accuracy, particularly in primary tumour staging.

SCREENING

The use of mpMRI to determine which men with an elevated PSA should undergo biopsy is currently the subject of two large clinical trials in Australia. MRI should be used with caution in this setting and then only in centres with established uro-radiological expertise and quality control mechanisms in place. There is sufficient evidence to justify using MRI to determine the need for repeat biopsy and to guide areas in which to focus repeat biopsy.

IMAGE-DIRECTED BIOPSY

MRI-directed biopsy is an exciting concept supported by promising early results, but none of the three proposed techniques have so far been proven superior to standard biopsy protocols. Further evidence of superior accuracy and core-efficiency over standard biopsy is required, before their costs and complexities in use can be justified.

TREATMENT SELECTION AND PLANNING

When used for primary-tumour staging (T-staging), MRI has limited sensitivity for T3 disease, but its specificity of greater than 95% may be useful in men with intermediate-high risk disease to identify those with advanced T3 disease not suitable for nerve sparing or for surgery at all. MRI appears to be of value in planning dosimetry in men undergoing radiotherapy, and in guiding selection for and monitoring on active surveillance.

Accuracy of multiparametric magnetic resonance imaging in confirming eligibility for active surveillance for men with prostate cancer

BACKGROUND

Active surveillance (AS) is an attempt to avoid overtreatment of clinically insignificant prostate cancer (PCa); however, patient selection remains controversial. Multiparametric prostate magnetic resonance imaging (MP-MRI) may help better select AS candidates.

METHODS

We reviewed a cohort of men who underwent MP-MRI with MRI/Ultrasound fusion-guided prostate biopsy and selected potential AS patients at entry using Johns Hopkins criteria. MP-MRI findings were assessed, including number of lesions, dominant lesion diameter, total lesion volume, prostate volume, and lesion density (calculated as total lesion volume/prostate volume). Lesions were assigned a suspicion score for cancer by MRI. AS criteria were reapplied based on the confirmatory biopsy, and accuracy of MP-MRI in predicting AS candidacy was assessed. Logistic regression modeling and chi-square statistics were used to assess associations between MP-MRI interpretation and biopsy results.

RESULTS

Eighty-five patients qualified for AS with a mean age of 60.2 years and mean prostate-specific antigen level of 4.8 ng/mL. Of these, 25 patients (29%) were reclassified as not meeting AS criteria based on confirmatory biopsy. Number of lesions, lesion density, and highest MRI lesion suspicion were significantly associated with confirmatory biopsy AS reclassification. These MRI-based factors were combined to create a nomogram that generates a probability for confirmed AS candidacy.

CONCLUSION

As clinicians counsel patients with PCa, MP-MRI may contribute to the decision-making process when considering AS. Three MRI-based factors (number of lesions, lesion suspicion, and lesion density) were associated with confirmatory biopsy outcome and reclassification. A nomogram using these factors has promising predictive accuracy for which future validation is necessary. Cancer 2013;119:3359-66. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Importance of prostate-specific antigen (PSA) as a predictive factor for concordance between the Gleason scores of prostate biopsies and RADICAL prostatectomy specimens

OBJECTIVE

To evaluate the concordance between the Gleason scores of prostate biopsies and radical prostatectomy specimens, thereby highlighting the importance of the prostate-specific antigen (PSA) level as a predictive factor of concordance.

METHODS

We retrospectively analyzed 253 radical prostatectomy cases performed between 2006 and 2011. The patients were divided into 4 groups for the data analysis and dichotomized according to the preoperative PSA, <10 ng/mL and ≥10 ng/mL. A p-score <0.05 was considered significant.

RESULTS

The average patient age was 63.3±7.8 years. The median PSA level was 9.3±4.9 ng/mL. The overall concordance between the Gleason scores was 52%. Patients presented preoperative PSA levels <10 ng/mL in 153 of 235 cases (65%) and ≥10 ng/mL in 82 of 235 cases (35%). The Gleason scores were identical in 86 of 153 cases (56%) in the <10 ng/mL group and 36 of 82 (44%) cases in the ≥10 ng/mL group (p=0.017). The biopsy underestimated the Gleason score in 45 (30%) patients in the <10 ng/mL group and 38 (46%) patients in the ≥10 ng/mL (p=0.243). Specifically, the patients with Gleason 3 + 3 scores according to the biopsies demonstrated global concordance in 56 of 110 cases (51%). In this group, the patients with preoperative PSA levels <10 ng/dL had higher concordance than those with preoperative PSA levels ≥10 ng/dL (61% x 23%, p=0.023), which resulted in 77% upgrading after surgery in those patients with PSA levels ≥10 ng/dl.

CONCLUSION

The Gleason scores of needle prostate biopsies and those of the surgical specimens were concordant in approximately half of the global sample. The preoperative PSA level was a strong predictor of discrepancy and might improve the identification of those patients who tended to be upgraded after surgery, particularly in patients with Gleason scores of 3 + 3 in the prostate biopsy and preoperative PSA levels ≥10 ng/mL.

Anti-Oligomannose Antibodies as Potential Serum Biomarkers of Aggressive Prostate Cancer

[Table: see text] This study bridges a carbohydrate microarray discovery and a large-scale serological validation of anti-oligomannose antibodies as novel serum biomarkers of aggressive prostate cancer (PCa). Experimentally, a Man9-cluster-specific enzyme-linked immunosorbent assay was established to enable sensitive detection of anti-Man9 antibodies in human sera. A large-cohort of men with PCa or benign prostatic hyperplasia (BPH) whose sera were banked at Stanford University was characterized using this assay. Subjects included patients with 100% Gleason grade 3 cancer (n = 84), with Gleason grades 4 and/or 5 cancer (n = 204), and BPH controls (n = 135). Radical prostatectomy Gleason grades and biochemical (PSA) recurrence served as key parameters for serum biomarker evaluation. It was found that IgG^Man9 and IgM^Man9 were widely present in the sera of men with BPH, as well as those with cancer. However, these antibody reactivities were significantly increased in the subjects with the largest volumes of high grade cancer. Detection of serum IgG^Man9 and IgM^Man9 significantly predicted the clinical outcome of PCa post-radical prostatectomy. Given these results, we suggest that IgG^Man9 and IgM^Man9 are novel serum biomarkers for monitoring aggressive progression of PCa. The potential of oligomannosyl antigens as targets for PCa subtyping and targeted immunotherapy is yet to be explored.

[Multiparametric MRI, elastography, contrastenhanced TRUS. Are there indications with reliable diagnostic advantages before prostate biopsy?]

Prostate cancer (PCA) is the most common malignancy in men with an increasing incidence and is responsible for about 11,000 deaths per year in Germany. Fortunately, the mortality of PCA has decreased in recent years despite the rising incidence reflecting improvements in diagnostic methods. Many new innovations in imaging techniques for PCA are available and may be helpful in early detection of PCA. Contrast-enhanced sonography, computer-assisted sonography, elastography and multiparametric magnetic resonance imaging (MRI) seem to be the most promising methods to increase the detection rate of PCA during diagnostic work-up. The value of these new innovative techniques concerning improvement in PCA detection is reviewed.

[Clinical characterization of prostate cancer potentially insignificant in the prostate biopsy]

OBJECTIVE

The aim of this study was to identify the rate of clinical significant disease (Gleason score>6 or tumor volume>0.5 cc in the RP specimen) among patients who had an insignificant prostate cancer on biopsy, evaluating the presence of prognostic factors.

PATIENTS AND METHODS

Patients who fulfilled the following criteria were included: PSA ≤ 10ng/ml, T1c disease, biopsy Gleason Score ≤ 6 affecting <5% of only 1 core and who had undergone a radical prostatectomy. The following variables were studied: Age, PSA, dPSA, free/total PSA ratio and prostatic volume assessed by transrectal ultrasound.

RESULTS

In a series of 2424 biopsies, 77 patients completely fulfilled the inclusion criteria, with 66.23% (n=51) of clinical significant disease in the prostatectomy specimen. No differences were observed between these patients and those with insignificant disease in age, PSA, free/total PSA ratio. However, prostatic volume was significantly greater and PSA density significantly lower in those patients with an insignificant disease. Statistical analysis using a logistical regression showed that dPSA was the only prognostic factor (OR: 25067.10, CI 95%: 26.79-2.34×10(7), P=.004).

CONCLUSIONS

These findings suggest that a high rate of patients who have a suspected insignificant prostate cancer on biopsy have a clinical significant disease, being dPSA the only independent prognostic factor.