Upgrading the Gleason score in extended prostate biopsy: implications for treatment choice

Understanding Spatial Correlation Between Multiparametric MRI Performance and Prostate Cancer

BACKGROUND

Multiparametric MRI (mpMRI) has shown a substantial impact on prostate cancer (PCa) diagnosis. However, the understanding of the spatial correlation between mpMRI performance and PCa location is still limited.

PURPOSE

To investigate the association between mpMRI performance and tumor spatial location within the prostate using a prostate sector map, described by Prostate Imaging Reporting and Data System (PI-RADS) v2.1.

STUDY TYPE

Retrospective.

SUBJECTS

One thousand one hundred forty-three men who underwent mpMRI before radical prostatectomy between 2010 and 2022.

FIELD STRENGTH/SEQUENCE

3.0 T. T2-weighted turbo spin-echo, a single-shot spin-echo EPI sequence for diffusion-weighted imaging, and a gradient echo sequence for dynamic contrast-enhanced MRI sequences.

ASSESSMENT

Integrated relative cancer prevalence (rCP), detection rate (DR), and positive predictive value (PPV) maps corresponding to the prostate sector map for PCa lesions were created. The relationship between tumor location and its detection/missing by radiologists on mpMRI compared to WMHP as a reference standard was investigated.

STATISTICAL TESTS

A weighted chi-square test was performed to examine the statistical differences for rCP, DR, and PPV of the aggregated sectors within the zone, anterior/posterior, left/right prostate, and different levels of the prostate with a statistically significant level of 0.05.

RESULTS

A total of 1665 PCa lesions were identified in 1143 patients, and from those 1060 lesions were clinically significant (cs)PCa tumors (any Gleason score [GS] ≥7). Our sector-based analysis utilizing weighted chi-square tests suggested that the left posterior part of PZ had a high likelihood of missing csPCa lesions at a DR of 67.0%. Aggregated sector analysis indicated that the anterior or apex locations in PZ had the significantly lowest csPCa detection at 67.3% and 71.5%, respectively.

DATA CONCLUSION

Spatial characteristics of the per-lesion-based mpMRI performance for diagnosis of PCa were studied. Our results demonstrated that there is a spatial correlation between mpMRI performance and locations of PCa on the prostate.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 2.

Artificial Intelligence in Uropathology

The global population is currently at unprecedented levels, with an estimated 7.8 billion people inhabiting the planet. We are witnessing a rise in cancer cases, attributed to improved control of cardiovascular diseases and a growing elderly population. While this has resulted in an increased workload for pathologists, it also presents an opportunity for advancement. The accurate classification of tumors and identification of prognostic and predictive factors demand specialized expertise and attention. Fortunately, the rapid progression of artificial intelligence (AI) offers new prospects in medicine, particularly in diagnostics such as image and surgical pathology. This article explores the transformative impact of AI in the field of uropathology, with a particular focus on its application in diagnosing, grading, and prognosticating various urological cancers. AI, especially deep learning algorithms, has shown significant potential in improving the accuracy and efficiency of pathology workflows. This comprehensive review is dedicated to providing an insightful overview of the primary data concerning the utilization of AI in diagnosing, predicting prognosis, and determining drug responses for tumors of the urinary tract. By embracing these advancements, we can look forward to improved outcomes and better patient care.

Optimal size threshold for PIRADSv2 category 5 upgrade and its positive predictive value: is it predictive of "very high" likelihood of clinically-significant cancer?

AIM

To identify the optimal size metric and threshold for Prostate Imaging Reporting and Data System (PIRADS) 5 upgrade, calculate its positive predictive value (PPV) for clinically-significant prostate cancer (csPCA), and determine if it is indicative of a "very high" likelihood of csPCA.

MATERIALS AND METHODS

One hundred and forty-three PIRADS 4 or 5 lesions were evaluated. Lesion diameters were used to calculate lesion volume (LV). Pearson correlation between maximum lesion diameter (MLD) and LV was calculated. Area under the curve (AUC) for discriminating csPCA (Gleason grade ≥ 3 + 4) was calculated using MLD and LV. Optimal size thresholds (using Youden index) and highly predictive size thresholds were identified for the whole prostate (WP), peripheral zone (PZ), and transitional zone (TZ).

RESULTS

There was high correlation between MLD and LV (r=0.77-0.81), with comparable AUCs for MLD and LV in the identification of csPCA in the WP (0.73, 0.72), PZ (0.73, 0.73), and TZ (0.79, 0.75). Optimal MLD thresholds were 1.4, 1.4, and 1.6 cm in the WP, PZ, and TZ respectively, with PPVs of 76%, 81%, and 69%, respectively. An MLD threshold of 2.7 cm would be needed in the WP to achieve a PPV approaching 90%, with sensitivity decreasing to 10%.

CONCLUSIONS

There is high correlation between MLD and LV with comparable discrimination of csPCA using each. PIRADSv2's 1.5 cm MLD threshold is near the optimal threshold for PIRADS 5 upgrade but has moderate PPV. A much higher threshold would be needed to increase its PPV, with significant sacrifice in sensitivity.

Low serum total testosterone level as a predictor of upgrading in low-risk prostate cancer patients after radical prostatectomy: A systematic review and meta-analysis

Purpose

To investigated the association between serum total testosterone and Gleason score upgrading of low-risk prostate cancer after radical prostatectomy (RP).

Materials and Methods

Medline, Web of Science, Embase, and Cochrane Library databases were searched to identify eligible studies published before October 2021. Multivariate adjusted odds ratios (ORs) and associated 95% confidence intervals (CIs) were calculated using random or fixed effects models.

Results

Five studies comprising 1,203 low-risk prostate cancer patients were included. The results showed that low serum total testosterone (<300 ng/dL) is associated with a high rate of Gleason score upgrading after RP (OR, 2.3; 95% CI, 1.38–3.83; p<0.001; I², 92.2%). Notably, sensitivity and meta-regression analyses further strengthen the reliability of our results.

Conclusions

Our results support the idea that low serum total testosterone is associated with a high rate of Gleason score upgrading in prostate cancer patients after RP. It is beneficial for urologist to ensure close monitoring of prostate-specific antigen levels and imaging examination when choosing non-RP treatment for low-risk prostate cancer patients.

Effect of dataset size, image quality, and image type on deep learning-based automatic prostate segmentation in 3D ultrasound

Three-dimensional (3D) transrectal ultrasound (TRUS) is utilized in prostate cancer diagnosis and treatment, necessitating time-consuming manual prostate segmentation. We have previously developed an automatic 3D prostate segmentation algorithm involving deep learning prediction on radially sampled 2D images followed by 3D reconstruction, trained on a large, clinically diverse dataset with variable image quality. As large clinical datasets are rare, widespread adoption of automatic segmentation could be facilitated with efficient 2D-based approaches and the development of an image quality grading method. The complete training dataset of 6761 2D images, resliced from 206 3D TRUS volumes acquired using end-fire and side-fire acquisition methods, was split to train two separate networks using either end-fire or side-fire images. Split datasets were reduced to 1000, 500, 250, and 100 2D images. For deep learning prediction, modified U-Net and U-Net++ architectures were implemented and compared using an unseen test dataset of 40 3D TRUS volumes. A 3D TRUS image quality grading scale with three factors (acquisition quality, artifact severity, and boundary visibility) was developed to assess the impact on segmentation performance. For the complete training dataset, U-Net and U-Net++ networks demonstrated equivalent performance, but when trained using split end-fire/side-fire datasets, U-Net++ significantly outperformed the U-Net. Compared to the complete training datasets, U-Net++ trained using reduced-size end-fire and side-fire datasets demonstrated equivalent performance down to 500 training images. For this dataset, image quality had no impact on segmentation performance for end-fire images but did have a significant effect for side-fire images, with boundary visibility having the largest impact. Our algorithm provided fast (<1.5 s) and accurate 3D segmentations across clinically diverse images, demonstrating generalizability and efficiency when employed on smaller datasets, supporting the potential for widespread use, even when data is scarce. The development of an image quality grading scale provides a quantitative tool for assessing segmentation performance.

TRUS-Guided Target Biopsy for a PI-RADS 3–5 Index Lesion to Reduce Gleason Score Underestimation: A Propensity Score Matching Analysis

Background

Magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS)-guided cognitive or image fusion biopsy is performed to target a prostate imaging reporting and data system (PI-RADS) 3–5 lesion. Biopsy Gleason score (GS) is frequently underestimated compared to prostatectomy GS. However, it is still unclear about how many cores on target are necessary to reduce undergrading and if additional cores around the target may improve grade prediction on surgical specimen.

Purpose

To determine the number of target cores and targeting strategy to reduce GS underestimation.

Materials and Methods

Between May 2017 and April 2020, a total of 385 patients undergoing target cognitive or image fusion biopsy of PI-RADS 3–5 index lesions and radical prostatectomies (RP) were 2:1 matched with propensity score using multiple variables and divided into the 1–4 core (n = 242) and 5–6 core (n = 143) groups, which were obtained with multiple logistic regression with restricted cubic spline curve. Target cores of 1–3 and 4–6 were sampled from central and peripheral areas, respectively. Pathologic outcomes and target cores were retrospectively assessed to analyze the GS difference or changes between biopsy and RP with Wilcoxon signed-rank test.

Results

The median of target cores was 3 and 6 in the 1–4 core and 5–6 core groups, respectively (p < 0.001). Restricted cubic spline curve showed that GS upgrade was significantly reduced from the 5th core and there was no difference between 5th and 6th cores. Among the matched patients, 35.4% (136/385; 95% confidence interval, 0.305–0.403) had a GS upgrade after RP. The GS upgrades in the 1–4 core and 5–6 core groups were observed in 40.6% (98/242, 0.343–0.470) and 26.6% (38/143, 0.195–0.346), respectively (p = 0.023). Although there was no statistical difference between the matched groups in terms of RP GS (p = 0.092), the 5–6 core group had significantly higher biopsy GS (p = 0.006) and lower GS change from biopsy to RP (p = 0.027).

Conclusion

Five or more target cores sampling from both periphery and center of an index tumor contribute to reduce GS upgrade.

Prospective evaluation of using multiparametric magnetic resonance imaging in cognitive fusion prostate biopsy compared to the standard systematic 12-core biopsy in the detection of prostate cancer

Purpose:

There is mounting evidence to suggest that multiparametric magnetic resonance imaging (mpMRI)-guided biopsy is better than systematic biopsy for the diagnosis of prostate cancer (PCa). Cognitive fusion biopsy (CFB) involves targeted biopsies of areas of suspicious lesions noted on the mpMRI by transrectal ultrasound (TRUS) operator. This study was undertaken to determine the accuracy of mpMRI of the prostate with Prostate Imaging–Reporting and Data System (PI-RADS) version 2 in detecting PCa. We also compare the cancer detection rates between systematic 12-core TRUS biopsy and CFB.

Materials and Methods:

Sixty-nine men underwent mpMRI of the prostate followed by TRUS biopsy. In addition to 12-core biopsy, CFB was performed on abnormal lesions detected on MRI.

Results:

Abnormal lesions were identified in 98.6% of the patients, and 59.4% had the highest PI-RADS score of 3 or more. With the use of PI-RADS 3 as cutoff, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI for the detection of PCa were 91.7%, 57.8%, 53.7%, and 92.8%, respectively. With the use of PI-RADS 4 as cutoff, the sensitivity, specificity, PPV, and NPV of mpMRI were 66.7%, 91.1%, 80%, and 83.7%, respectively. Systematic biopsy detected more PCa compared to CFB (29% vs. 26.1%), but CFB detected more significant (Gleason grade ≥7) PCa (17.4% vs. 14.5%) (P < 0.01). CFB cores have a higher PCa detection rate as compared to systematic cores (P < 0.01).

Conclusions:

mpMRI has a good predictive ability for PCa. CFB is superior to systematic biopsy in the detection of the significant PCa.

Automated segmentation of prostate zonal anatomy on T2-weighted (T2W) and apparent diffusion coefficient (ADC) map MR images using U-Nets

PURPOSE

Accurate regional segmentation of the prostate boundaries on magnetic resonance (MR) images is a fundamental requirement before automated prostate cancer diagnosis can be achieved. In this paper, we describe a novel methodology to segment prostate whole gland (WG), central gland (CG), and peripheral zone (PZ), where PZ + CG = WG, from T2W and apparent diffusion coefficient (ADC) map prostate MR images.

METHODS

We designed two similar models each made up of two U-Nets to delineate the WG, CG, and PZ from T2W and ADC map MR images, separately. The U-Net, which is a modified version of a fully convolutional neural network, includes contracting and expanding paths with convolutional, pooling, and upsampling layers. Pooling and upsampling layers help to capture and localize image features with a high spatial consistency. We used a dataset consisting of 225 patients (combining 153 and 72 patients with and without clinically significant prostate cancer) imaged with multiparametric MRI at 3 Tesla.

RESULTS AND CONCLUSION

Our proposed model for prostate zonal segmentation from T2W was trained and tested using 1154 and 1587 slices of 100 and 125 patients, respectively. Median of Dice similarity coefficient (DSC) on test dataset for prostate WG, CG, and PZ were 95.33 ± 7.77%, 93.75 ± 8.91%, and 86.78 ± 3.72%, respectively. Designed model for regional prostate delineation from ADC map images was trained and validated using 812 and 917 slices from 100 and 125 patients. This model yielded a median DSC of 92.09 ± 8.89%, 89.89 ± 10.69%, and 86.1 ± 9.56% for prostate WG, CG, and PZ on test samples, respectively. Further investigation indicated that the proposed algorithm reported high DSC for prostate WG segmentation from both T2W and ADC map MR images irrespective of WG size. In addition, segmentation accuracy in terms of DSC does not significantly vary among patients with or without significant tumors.

SIGNIFICANCE

We describe a method for automated prostate zonal segmentation using T2W and ADC map MR images independent of prostate size and the presence or absence of tumor. Our results are important in terms of clinical perspective as fully automated methods for ADC map images, which are considered as one of the most important sequences for prostate cancer detection in the PZ and CG, have not been reported previously.

Metabolic syndrome increases the risk of upgrading and upstaging in patients with prostate cancer on biopsy: a radical prostatectomy multicenter cohort study

BACKROUND

Recently metabolic syndrome has been associated to an increased risk of advanced disease. Aim of our study is to investigate the association of metabolic syndrome (MetS) with the risk of prostate cancer (PCa) upgrading and upstaging after radical prostatectomy (RP).

METHODS

From 2012 and 2016, 400 consecutive men underwent RP at three referral centers in Italy and were enrolled into a prospective database. Blood pressure, body mass index and waist circumference were measured before RP. Blood samples were also collected and tested for total PSA, fasting glucose, triglycerides and HDLs. Logistic regression analyses were used to assess the association between MetS, defined according to Adult Treatment Panel III, and the risk of upgrading and upstaging), using the new Prognostic Grade Group (PGG) classification system.

RESULTS

Overall 148/400 (37%) men were diagnosed with MetS and most of these reported up-grading (54.5%) and up-staging (56.8%). These events were significantly more common in this population and MetS was a risk factor for up-staging and up-grading on multivariable analysis. Patients with MetS presented worst accuracy (72 vs. 84%; p = 0.001) and worst kappa coefficient of agreement (k = 0.439 ± 0.071 vs. k = 0.553 ± 0.071) between needle biopsy and radical prostatectomy specimens when compared to patients without MetS.

CONCLUSIONS

MetS represents a significant risk factor for upgrading and upstaging. Accuracy of PGG system on biopsy is poor in patients with MetS, therefore results should be evaluated carefully in this population.

Robust 2-D-3-D Registration Optimization for Motion Compensation During 3-D TRUS-Guided Biopsy Using Learned Prostate Motion Data

In magnetic resonance (MR)-targeted, 3-D transrectal ultrasound (TRUS)-guided biopsy, prostate motion during the procedure increases the needle targeting error and limits the ability to accurately sample MR-suspicious tumor volumes. The robustness of the 2-D-3-D registration methods for prostate motion compensation is impacted by local optima in the search space. In this paper, we analyzed the prostate motion characteristics and investigated methods to incorporate such knowledge into the registration optimization framework to improve robustness against local optima. Rigid motion of the prostate was analyzed adopting a mixture-of-Gaussian (MoG) model using 3-D TRUS images acquired at bilateral sextant probe positions with a mechanically assisted biopsy system. The learned motion characteristics were incorporated into Powell's direction set method by devising multiple initial search positions and initial search directions. Experiments were performed on data sets acquired during clinical biopsy procedures, and registration error was evaluated using target registration error (TRE) and converged image similarity metric values after optimization. After incorporating the learned initialization positions and directions in Powell's method, 2-D-3-D registration to compensate for motion during prostate biopsy was performed with rms ± std TRE of 2.33 ± 1.09 mm with ~3 s mean execution time per registration. This was an improvement over 3.12 ± 1.70 mm observed in Powell's standard approach. For the data acquired under clinical protocols, the converged image similarity metric value improved in ≥8% of the registrations whereas it degraded only ≤1% of the registrations. The reported improvements in optimization indicate useful advancements in robustness to ensure smooth clinical integration of a registration solution for motion compensation that facilitates accurate sampling of the smallest clinically significant tumors.

Real-time registration of 3D to 2D ultrasound images for image-guided prostate biopsy

PURPOSE

During image-guided prostate biopsy, needles are targeted at tissues that are suspicious of cancer to obtain specimen for histological examination. Unfortunately, patient motion causes targeting errors when using an MR-transrectal ultrasound (TRUS) fusion approach to augment the conventional biopsy procedure. This study aims to develop an automatic motion correction algorithm approaching the frame rate of an ultrasound system to be used in fusion-based prostate biopsy systems. Two modes of operation have been investigated for the clinical implementation of the algorithm: motion compensation using a single user initiated correction performed prior to biopsy, and real-time continuous motion compensation performed automatically as a background process.

METHODS

Retrospective 2D and 3D TRUS patient images acquired prior to biopsy gun firing were registered using an intensity-based algorithm utilizing normalized cross-correlation and Powell's method for optimization. 2D and 3D images were downsampled and cropped to estimate the optimal amount of image information that would perform registrations quickly and accurately. The optimal search order during optimization was also analyzed to avoid local optima in the search space. Error in the algorithm was computed using target registration errors (TREs) from manually identified homologous fiducials in a clinical patient dataset. The algorithm was evaluated for real-time performance using the two different modes of clinical implementations by way of user initiated and continuous motion compensation methods on a tissue mimicking prostate phantom.

RESULTS

After implementation in a TRUS-guided system with an image downsampling factor of 4, the proposed approach resulted in a mean ± std TRE and computation time of 1.6 ± 0.6 mm and 57 ± 20 ms respectively. The user initiated mode performed registrations with in-plane, out-of-plane, and roll motions computation times of 108 ± 38 ms, 60 ± 23 ms, and 89 ± 27 ms, respectively, and corresponding registration errors of 0.4 ± 0.3 mm, 0.2 ± 0.4 mm, and 0.8 ± 0.5°. The continuous method performed registration significantly faster (P < 0.05) than the user initiated method, with observed computation times of 35 ± 8 ms, 43 ± 16 ms, and 27 ± 5 ms for in-plane, out-of-plane, and roll motions, respectively, and corresponding registration errors of 0.2 ± 0.3 mm, 0.7 ± 0.4 mm, and 0.8 ± 1.0°.

CONCLUSIONS

The presented method encourages real-time implementation of motion compensation algorithms in prostate biopsy with clinically acceptable registration errors. Continuous motion compensation demonstrated registration accuracy with submillimeter and subdegree error, while performing < 50 ms computation times. Image registration technique approaching the frame rate of an ultrasound system offers a key advantage to be smoothly integrated to the clinical workflow. In addition, this technique could be used further for a variety of image-guided interventional procedures to treat and diagnose patients by improving targeting accuracy.

Low serum testosterone predicts upgrading and upstaging of prostate cancer after radical prostatectomy

Often, pathological Gleason Score (GS) and stage of prostate cancer (PCa) were inconsistent with biopsy GS and clinical stage. However, there were no widely accepted methods predicting upgrading and upstaging PCa. In our study, we investigated the association between serum testosterone and upgrading or upstaging of PCa after radical prostatectomy (RP). We enrolled 167 patients with PCa with biopsy GS ≤6, clinical stage ≤T2c, and prostate-specific antigen (PSA) <10 ng ml⁻¹ from April 2009 to April 2015. Data including age, body mass index, preoperative PSA level, comorbidity, clinical presentation, and preoperative serum total testosterone level were collected. Upgrading occurred in 62 (37.1%) patients, and upstaging occurred in 73 (43.7%) patients. Preoperative testosterone was lower in the upgrading than nonupgrading group (3.72 vs 4.56, P< 0.01). Patients in the upstaging group had lower preoperative testosterone than those in the nonupstaging group (3.84 vs 4.57, P= 0.01). In multivariate logistic regression analysis, as both continuous and categorical variables, low serum testosterone was confirmed to be an independent predictor of pathological upgrading (P = 0.01 and P= 0.01) and upstaging (P = 0.01 and P = 0.02) after RP. We suggest that low serum testosterone (<3 ng ml⁻¹) is associated with a high rate of upgrading and upstaging after RP. It is better for surgeons to ensure close monitoring of PSA levels and imaging examination when selecting non-RP treatment, to be cautious in proceeding with nerve-sparing surgery, and to be enthusiastic in performing extended lymph node dissection when selecting RP treatment for patients with low serum testosterone.

Computer-Aided Prostate Cancer Detection Using Ultrasound RF Time Series: In Vivo Feasibility Study

This paper presents the results of a computer-aided intervention solution to demonstrate the application of RF time series for characterization of prostate cancer, in vivo.

METHODS

We pre-process RF time series features extracted from 14 patients using hierarchical clustering to remove possible outliers. Then, we demonstrate that the mean central frequency and wavelet features extracted from a group of patients can be used to build a nonlinear classifier which can be applied successfully to differentiate between cancerous and normal tissue regions of an unseen patient.

RESULTS

In a cross-validation strategy, we show an average area under receiver operating characteristic curve (AUC) of 0.93 and classification accuracy of 80%. To validate our results, we present a detailed ultrasound to histology registration framework.

CONCLUSION

Ultrasound RF time series results in differentiation of cancerous and normal tissue with high AUC.

Preoperative low serum testosterone is associated with high-grade prostate cancer and an increased Gleason score upgrading

BACKGROUND

To compare histological feature of prostate cancer (PCa) according androgenic status in patients who underwent radical prostatectomy (RP).

METHODS

Between March 2007 and September 2013, we prospectively analysed 937 patients who were referred to our centre for RP. Clinical, pathological and biological data have been prospectively collected. Preoperative total testosterone (TT) and bioavailable testosterone (BT) serum determinations were carried out. The threshold for low serum testosterone was set at TT<3 ng/ml. Preoperative PSA value was registered. Gleason score (GS) and predominant Gleason pattern were determined in prostate biopsies and in prostate tissue specimens, crosschecked by two uro-pathologists.

RESULTS

Nine hundred and thirty-seven consecutive patients were included. In all, 14.9% patients had low TT in the population. An exact match between biopsy and prostate specimens in GS grading was observed for 50.6% patients (n=474). Also, 40.9% of all patients were upgraded (n=383): 45.3% (n=63) in low serum testosterone patients and 40.1% (n=320) in normal serum testosterone patients. For prostate specimens, the proportion of patients with predominant Gleason pattern 4 was higher in patients with low TT compared with normal TT (41.7% vs 29.1%, P=0.0029). In all, 20.1% were upgraded from predominant Gleason pattern 3 on biopsies specimen to predominant Gleason 4 pattern on the prostate specimen in patients with low TT, whereas 11.6% were upgraded for normal TT patients (P=0.002).

CONCLUSIONS

Low serum testosterone is an independent risk factor for predominant Gleason pattern 4 on prostate specimen after RP and for upgrading from low- to high-grade cancer between prostate needle biopsies and RP specimen. This observation should be taken into account in localised PCa management, especially for active surveillance or when a nerve-sparing approach is considered.

Ultrasound-Based Characterization of Prostate Cancer Using Joint Independent Component Analysis

OBJECTIVE

This paper presents the results of a new approach for selection of RF time series features based on joint independent component analysis for in vivo characterization of prostate cancer.

METHODS

We project three sets of RF time series features extracted from the spectrum, fractal dimension, and the wavelet transform of the ultrasound RF data on a space spanned by five joint independent components. Then, we demonstrate that the obtained mixing coefficients from a group of patients can be used to train a classifier, which can be applied to characterize cancerous regions of a test patient.

RESULTS

In a leave-one-patient-out cross validation, an area under receiver operating characteristic curve of 0.93 and classification accuracy of 84% are achieved.

CONCLUSION

Ultrasound RF time series can be used to accurately characterize prostate cancer, in vivo without the need for exhaustive search in the feature space.

SIGNIFICANCE

We use joint independent component analysis for systematic fusion of multiple sets of RF time series features, within a machine learning framework, to characterize PCa in an in vivo study.

Controlling RECK miR21 Promotes Tumor Cell Invasion and Is Related to Biochemical Recurrence in Prostate Cancer

The search for biomarkers to characterize prostate cancer aggressiveness has been the objective for the majority of researchers involved with the most prevalent tumor in men. MiRNAs are important for the control of many cellular functions and their deregulation is involved with tumor development and progression. To find miRNAs differentially expressed in prostate cancer and their relation to prognostic factors and biochemical recurrence we studied 53 surgical specimens from men who underwent radical prostatectomy, through a microarray analysis using the microarray platform (GeneChip® miRNA Array - Affymetrix) with more than 46,000 probes and 847 mature human miRNAs and transcripts. We defined different as an expression level greater or less than 1.1 with p<0.05. The validation study using qRT-PCR had confirmed miR21 as overexpressed in tumor that have recurred with a risk of 2.5. Transfection of miR-21 using lipid based assay in DU145 cell line, showed decrease in expression of RECK resulting in increase in expression of MMP9. Invasion assay with Matrigel showed increase in tumor cell invasion after miR-21 transfection. We conclude that miR-21 overexpression is related to increased biochemical recurrence after surgical treatment of prostate cancer. And the negative control of RECK results in overexpression of MMP9 promotes increasing tumor cell invasion supporting miR-21 as an oncomiR related to aggressiveness in prostate cancer.

Discrimination of prostate carcinoma from benign prostate tissue fragments in vitro by estimating the gross biochemical alterations through Raman spectroscopy

Raman spectroscopy has been proposed for detecting biochemical alterations in prostate cancer (PrCa) compared to benign prostate tissue in in vitro fragments from surgery for diagnostic purposes. Freezer-stored fragments of human prostate tissues were unfrozen and submitted to Raman spectroscopy with a dispersive spectrometer (830-nm and 200-mW laser parameters, 30-s exposure time). Fragments were fixed and submitted to histopathology to grade PrCa according to Gleason score. A total of 160 spectra were taken from 32 samples (16 benign tissues and 16 PrCa tissues). The relative concentrations of selected biochemicals were estimated using a least-squares fitting model applied to the spectra of pure compounds and the tissue spectrum. A discrimination model was developed employing the most statistically relevant compounds with capability of separating PrCa from benign tissues. The fitting model revealed that actin, hemoglobin, elastin, phosphatidylcholine, and water are the most important biochemicals to discriminate prostate depending on the Gleason score. A discrimination based on Euclidean distance using the relative concentrations of phosphatidylcholine and water showed the higher accuracy of 74 % to discriminate PrCa from benign tissue. Raman spectroscopy is an analytical technique with possibility for identifying biochemical constitution of prostate and could be used for diagnostic purposes.

3D versus 2D Systematic Transrectal Ultrasound-Guided Prostate Biopsy: Higher Cancer Detection Rate in Clinical Practice

Objectives. To compare prostate cancer detection rates of extended 2D versus 3D biopsies and to further assess the clinical impact of this method in day-to-day practice. Methods. We analyzed the data of a cohort of 220 consecutive patients with no prior history of prostate cancer who underwent an initial prostate biopsy in daily practice due to an abnormal PSA and/or DRE using, respectively, the classical 2D and the new 3D systems. All the biopsies were done by a single experienced operator using the same standardized protocol. Results. There was no significant difference in terms of age, total PSA, or prostate volume between the two groups. However, cancer detection rate was significantly higher using the 3D versus the 2D system, 50% versus 34% (P < 0.05). There was no statistically significant difference while comparing the 2 groups in term of nonsignificant cancer detection. Conclusion. There is reasonable evidence demonstrating the superiority of the 3D-guided biopsies in detecting prostate cancers that would have been missed using the 2D extended protocol.

Underexpression of MMP-2 and its regulators, TIMP2, MT1-MMP and IL-8, is associated with prostate cancer

OBJECTIVE

Extracellular matrix homeostasis is strictly maintained by a coordinated balance between the expression of metalloproteinases (MMPs) and their regulators. The purpose of this study was to investigate whether MMP-2 and its specifi c regulators, TIMP-2, MT1-MMP and IL-8, are expressed in a reproducible, specific pattern and if the profiles are related to prognosis and clinical outcome of prostate cancer (PCa).

MATERIALS AND METHODS

MMP-2, TIMP-2, MT1-MMP and IL-8 expression levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in freshly frozen malignant and benign tissue specimens collected from 79 patients with clinically localized PCa who underwent radical prostatectomies. The control group consisted of 11 patients with benign prostate hyperplasia (BPH). The expression profile of the MMP-2 and its regulators were compared using Gleason scores, pathological stage, pre-operative PSA levels and the fi nal outcome of the PCa.

RESULTS

The analysis of 79 specimens of PCa revealed that MMP-2, TIMP-2, MT1-MMP and IL-8 were underexpressed at 60.0%, 72.2%, 62.0% and 65.8%, respectively, in malignant prostatic tissue in relation to BPH samples. Considering the prognostic parameters, we demonstrated that high Gleason score tumors (≥ 7) overexpressed MMP-2 (p = 0.048) and TIMP-2 (p = 0.021), compared to low Gleason score tumors (< 7).

CONCLUSION

We have demonstrated that MMP-2 and its regulators are underexpressed in PCa. Alternatively, overexpression of MMP-2 and TIMP-2 was related to higher Gleason score tumors. We postulate that alterations in metalloproteinase expression may be important in the control of tissue homeostasis related to prostate carcinogenesis and tumor behavior.

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.

Importance and determinants of Gleason score undergrading on biopsy sample of prostate cancer in a population-based study

Background

In this population-based study, we investigated the degree of concordance between Gleason scores obtained from prostate biopsies and those obtained from prostatectomy specimens, as well as the determinants of biopsy understaging.

Methods

We considered for this study all 371 prostate cancer patients recorded at the Geneva Cancer Registry diagnosed from 2004 to 2006 who underwent a radical prostatectomy. We used the kappa statistic to evaluate the Gleason score concordance from biopsy and prostatectomy specimens. Logistic regression was used to determine the parameters that predict the undergrading of the Gleason score in prostate biopsies.

Results

The kappa statistic between biopsy and prostatectomy Gleason score was 0.42 (p < 0.0001), with 67% of patients exactly matched, and 26% (n = 95) patients with Gleason score underestimated by the biopsy. In a multi-adjusted model, increasing age, advanced clinical stage, having less than ten biopsy cores, and longer delay between the two procedures, were all independently associated with biopsy undergrading. In particular, the proportion of exact match increased to 72% when the patients had ten or more needle biopsy cores. The main limitation of the study is that both biopsy and prostatectomy specimens were examined by different laboratories.

Conclusions

The data show that concordance between biopsy and prostatectomy Gleason scores lies within the classic clinical standards in this population-based study. The number of biopsy cores appears to strongly impact on the concordance between biopsy and radical prostatectomy Gleason score.

[Voluntary abortion and domestic violence among women attended at a public maternity hospital of Salvador-BA]

Quantitative study in order to study domestic violence in women with induced abortion. Interviews were conducted with 147 women hospitalized for induced abortion in a public maternity hospital in Salvador, Bahia. The subjects are characterized by mostly women, black, poorly educated, economically dependent on spouses, experienced psychological abuse, physical and sexual abuse committed by their spouses. Almost half of the women were victims of domestic violence during the current pregnancy, and that was the reason for inducing abortion for 67% of them. The study reveals an association between experience of domestic violence and induced abortion. As mental health consequences, they developed symptoms of post trauma stress disorder. It is necessary that the health professionals consider the cues to identify domestic violence as a health problem associated with induced abortion, which requires a transformation on the training model, including domestic violence as a health issue.

Upgrading and downgrading of prostate cancer from biopsy to radical prostatectomy: incidence and predictive factors using the modified Gleason grading system and factoring in tertiary grades

BACKGROUND

Prior studies assessing the correlation of Gleason score (GS) at needle biopsy and corresponding radical prostatectomy (RP) predated the use of the modified Gleason scoring system and did not factor in tertiary grade patterns.

OBJECTIVE

To assess the relation of biopsy and RP grade in the largest study to date.

DESIGN, SETTING, AND PARTICIPANTS

A total of 7643 totally embedded RP and corresponding needle biopsies (2004-2010) were analyzed according to the updated Gleason system.

INTERVENTIONS

All patients underwent prostate biopsy prior to RP.

MEASUREMENTS

The relation of upgrading or downgrading to patient and cancer characteristics was compared using the chi-square test, Student t test, and multivariable logistic regression.

RESULTS AND LIMITATIONS

A total of 36.3% of cases were upgraded from a needle biopsy GS 5-6 to a higher grade at RP (11.2% with GS 6 plus tertiary). Half of the cases had matching GS 3+4=7 at biopsy and RP with an approximately equal number of cases downgraded and upgraded at RP. With biopsy GS 4+3=7, RP GS was almost equally 3+4=7 and 4+3=7. Biopsy GS 8 led to an almost equal distribution between RP GS 4+3=7, 8, and 9-10. A total of 58% of the cases had matching GS 9-10 at biopsy and RP. In multivariable analysis, increasing age (p<0.0001), increasing serum prostate-specific antigen level (p<0.0001), decreasing RP weight (p<0.0001), and increasing maximum percentage cancer/core (p<0.0001) predicted the upgrade from biopsy GS 5-6 to higher at RP. Despite factoring in multiple variables including the number of positive cores and the maximum percentage of cancer per core, the concordance indexes were not sufficiently high to justify the use of nomograms for predicting upgrading and downgrading for the individual patient.

CONCLUSIONS

Almost 20% of RP cases have tertiary patterns. A needle biopsy can sample a tertiary higher Gleason pattern in the RP, which is then not recorded in the standard GS reporting, resulting in an apparent overgrading on the needle biopsy.

Quantification of prostate deformation due to needle insertion during TRUS-guided biopsy: comparison of hand-held and mechanically stabilized systems

PURPOSE

Prostate biopsy is the clinical standard for the definitive diagnosis of prostate cancer. To overcome the limitations of 2D TRUS-guided biopsy systems when targeting preplanned locations, systems have been developed with 3D guidance to improve the accuracy of cancer detection. Prostate deformation due to needle insertion and biopsy gun firing is a potential source of error that can cause target misalignments during biopsies.

METHODS

The authors used nonrigid registration of 2D TRUS images to quantify the deformation that occurs during the needle insertion and the biopsy gun firing procedure and compare this effect in biopsies performed using a hand-held TRUS probe to those performed using a mechanically assisted 3D TRUS-guided biopsy system. The authors calculated a spatially varying 95% confidence interval on the prostate tissue motion and analyzed this motion both as a function of distance to the biopsy needle and as a function of distance to the lower piercing point of the prostate. The former is relevant because biopsy targets lie along the needle axis, and the latter is of particular importance due to the reported high concentration of prostate cancer in the peripheral zone, a substantial portion of which lies on the posterior side of the prostate where biopsy needles enter the prostate after penetrating the rectal wall during transrectal biopsy.

RESULTS

The results show that for both systems, the tissue deformation is such that throughout the length of the needle axis, including regions proximal to the lower piercing point, spherical tumors with a radius of 2.1 mm or more can be sampled with 95% confidence under the assumption of zero error elsewhere in the biopsy system. More deformation was observed in the direction orthogonal to the needle axis compared to the direction parallel to the needle axis; this is of particular importance given the long, narrow shape of the biopsy core. The authors measured lateral tissue motion proximal to the needle axis of not more than 1.5 mm, with 95% confidence. The authors observed a statistically significant and clinically insignificant maximum difference of 0.38 mm in the deformation, resulting from the hand-held and mechanically assisted systems along the needle axis, and the mechanical system resulted in a lower relative increase in deformation proximal to the needle axis during needle insertion, as well as lower variability of deformation during biopsy gun firing.

CONCLUSIONS

Given the clinical need to biopsy tumors of volume greater than or equal to 0.5 cm3, corresponding to spherical tumors with a radius of 5 mm or more, the tissue motion induced by needle insertion and gun firing is an important consideration when setting the design specifications for TRUS-guided prostate biopsy systems.

Are we able to correctly identify prostate cancer patients who could be adequately treated by focal therapy?

INTRODUCTION AND OBJECTIVE

Because of the improvements on detection of early stage prostate cancer over the last decade, focal therapy for localized prostate cancer (PC) has been proposed for patients with low-risk disease. Such treatment would allow the control of cancer, thereby diminishing side effects, such as urinary incontinence and sexual dysfunction, which have an enormous impact on quality of life. The critical issue is whether it is possible to preoperatively predict clinically significant unifocal or unilateral prostate cancer with sufficient accuracy. Our aim is to determine whether there is any preoperative feature that can help select the ideal patient for focal therapy.

MATERIAL AND METHODS

A total of 599 patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsy followed by radical prostatectomy to treat PC were examined in our laboratory between 2001 and 2009. We established very restricted criteria to select patients with very-low-risk disease for whom focal therapy would be suitable (only 1 biopsy core positive, tumor no larger than 80% of a single core, no perineural invasion, PSA serum level < 10 ng/ml, Gleason score < 7 and clinical stage T1c, T2a-b). We defined 2 groups of patients who would be either adequately treated or not treated by focal therapy. The primary endpoint was the evaluation of preoperative features in order to identify which parameters should be considered when choosing good candidates for focal therapy.

RESULTS

Fifty-six out of 599 patients met our criteria. The mean age was 59 years, and the mean number of biopsy cores was 14.4. Forty-seven (83.9%) were staged T1c, and 9 (16.1%) were staged T2a-b. Forty-four (78.6%) patients could be considered to have been adequately treated by focal therapy, and 12 (21.4%) could not. There was no statistical difference between the 2 groups considering age, clinical stage, PSA levels, Gleason score, and tumor volume in the biopsy. All 12 patients who could be considered inadequately treated had a bilateral, significant secondary tumor, 58.3% had Gleason ≥ 7, and 25% were staged pT3.

CONCLUSION

Although focal therapy might be a good option for patients with localized prostate cancer, we are so far unable to select which of them would benefit from it based on preoperative data, even using very restricted criteria, and a considerable proportion of men would still be left undertreated.

PSA-detected prostate cancer and the potential for dedifferentiation--estimating the proportion capable of progression

The aims were to determine whether prostate-specific antigen (PSA)-detected prostate cancers progress to higher Gleason score during the preclinical screen-detectable phase, and, if so, to estimate the proportion of tumours with progressive potential. We developed two multi-state Markov chain models to represent the natural history of two tumour populations, one with (Model I) and the other without (Model II) the potential for progression. For each, we derived the transition rates between the states and used these estimates to calculate the expected prevalence of preclinical low and intermediate-to-high Gleason score prostate cancers, using data from the Prostate Testing for Cancer and Treatment (ProtecT) study on 2,310 prostate cancers detected by PSA testing in 71,511 men 50-69 years. We compared the expected prevalence for each tumour population to that of the observed based on ProtecT and the European Randomised Study on Screening for Prostate Cancer (ERSPC)-Rotterdam Centre's first round screening data, the latter allowing independent assessment of the two models. The overall expected proportion of low Gleason score tumours was 0.56 under Model I and 0.81 under Model II, whereas the observed proportion based on either ProtecT or ERSPC-Rotterdam was 0.69. Using the observed prevalence from ERSPC-Rotterdam, we estimated that 22, 33 and 66% of the tumours in men aged 55-59, 60-64 and 65-69 years, respectively, had the potential for progression in the preclinical phase. PSA-detected prostate cancers are a mixture of progressive and non-progressive tumours with respect to Gleason score. The former may potentially benefit from screening. Identifying cancers with the potential for progression is important to target screening.

MicroRNA-100 expression is independently related to biochemical recurrence of prostate cancer

PURPOSE

Abnormal miRNA expression has emerged as crucial factors in carcinogenesis and is important in the comprehension of prostate cancer behavior. We determined the correlation of miRNA expression profiles with prostate cancer progression.

MATERIALS AND METHODS

We studied frozen specimens from 49 patients treated for prostate cancer with radical prostatectomy. We intentionally chose 28 men without and 21 with biochemical recurrence, defined as prostate specific antigen greater than 0.2 ng/ml. The expression of 14 miRNAs was determined by quantitative reverse transcriptase-polymerase chain reaction. All radical prostatectomy specimens were studied in toto to determine tumor volume, Gleason score and 2002 TNM pathological stage. Benign prostate tissue from benign prostatic hyperplasia served as a control.

RESULTS

Four miRNAs were related to tumor recurrence. Using the Cox regression test the risk of recurrence was 3.0, 3.3, 2.7 and 3.4 for high levels of miR-100, miR-145, miR-191 and miR-let7c, respectively. When considering statistically significant clinical variables on univariate analysis of biochemical-free survival, prostate specific antigen and tumor volume, results revealed that miR-100 and tumor volume were independently related to tumor recurrence.

CONCLUSIONS

A high level of miR-100 is related to biochemical recurrence of localized prostate cancer in patients treated with radical prostatectomy. The role of miR-100 during carcinogenesis must be resolved in future studies to better understand the molecular pathways in which miR-100 is involved. This may open the possibility of using it as a prognostic marker and inspire the development of a target drug.