How reliable is 12-core prostate biopsy procedure in the detection of prostate cancer?

Current Management Strategy for Active Surveillance in Prostate Cancer

PURPOSE OF REVIEW

Active surveillance has been increasingly utilized as a strategy for the management of favorable-risk, localized prostate cancer. In this review, we describe contemporary management strategies of active surveillance, with a focus on traditional stratification schemes, new prognostic tools, and patient outcomes.

RECENT FINDINGS

Patient selection, follow-up strategy, and indication for delayed intervention for active surveillance remain centered around PSA, digital rectal exam, and biopsy findings. Novel tools which include imaging, biomarkers, and genetic assays have been investigated as potential prognostic adjuncts; however, their role in active surveillance remains institutionally dependent. Although 30-50% of patients on active surveillance ultimately undergo delayed treatment, the vast majority will remain free of metastasis with a low risk of dying from prostate cancer. The optimal method for patient selection into active surveillance is unknown; however, cancer-specific mortality rates remain excellent. New prognostication tools are promising, and long-term prospective, randomized data regarding their use in active surveillance will be beneficial.

[Ultrasonography of the prostate gland : From B‑image through multiparametric ultrasound to targeted biopsy]

BACKGROUND

Prostate cancer is the most frequent cancer in men. The diagnosis is normally achieved by a systematic prostate biopsy; however, this is a randomized approach by which a substantial number of significant carcinomas go undetected. For this reason, in recent years imaging techniques have been continuously developed, which enable visualization and therefore targeted biopsies.

STANDARD PROCEDURE

The use of systematic biopsies is a standard procedure for the detection of prostate cancer. The quality of biopsies can be increased if the prostate is examined for the presence of suspected cancerous alterations during the biopsy. This can be carried out using multiparametric transrectral ultrasound.

PERFORMANCE

Multiparametric ultrasound within the framework of a targeted biopsy increases the detection rate of significant prostate carcinomas with a simultaneous decrease in detection of insignificant carcinomas; however, the diagnostic reliability and the evidence level of multiparametric transrectal ultrasound are not yet sufficiently high to be able to replace a systematic biopsy.

CONCLUSION

In the hands of a well-trained examiner multiparametric transrectal ultrasound represents a good method for detection of prostate carcinomas. With the progression in technical developments of ultrasound technology, the detection rate will presumably be further increased.

Outcomes of combination MRI-targeted and transperineal template biopsy in restaging low-risk prostate cancer for active surveillance

Objective

Active surveillance (AS) offers a strategy to reduce overtreatment and now is a widely accepted treatment option for low-risk prostate cancer. An ideal tool for risk-stratification would detect aggressive cancers and exclude such men from taking up AS in the first place. We evaluate if a combination of transperineal template biopsy with magnetic resonance imaging (MRI)-targeted biopsy identifies significant prostate cancer amongst men initially diagnosed with low-risk prostate cancer.

Methods

This prospective, single-blinded study included men with low-risk prostate cancer (D'Amico's Criteria) diagnosed on conventional transrectal ultrasound-guided biopsy. Patients first underwent multiparametric MRI of the prostate ≥6 weeks after initial biopsy. Each suspicious lesion is mapped and assigned a Prostate Imaging Reporting and Data System (PIRADS) score. Template biopsy is first performed with the surgeon blinded to MRI findings followed by MRI-targeted biopsy using a robotic transperineal biopsy platform.

Results

The age of the 19 men included is 65.4 ± 4.9 years (mean ± SD). Prostate specific antigen (PSA) at diagnosis and at the time of transperineal biopsy were comparable (7.3 ± 1.7 ng/mL and 7.0 ± 1.8 ng/mL, p = 0.67), so were prostate volumes (34.2 ± 8.9 mL and 32.1 ± 13.4 mL, p = 0.28). MRI-targeted biopsy had a higher percentage of cancer detection per core compared to template biopsy (11.7% vs. 6.5%, p = 0.02), this was more than 3 times superior for Gleason 7 disease (5.9% vs. 1.6%, p < 0.01). Four of 18 (22.2%) patients with MRI lesions had significant disease with MRI-targeted biopsy alone. Three of 19 patients (15.8%) had significant disease with template biopsy alone. In combination, both techniques upclassified five patients (26.3%), all of whom underwent radical prostatectomy. Whole mount histology confirmed tumour location and grade. All six patients with PIRADS 5 lesions had cancer detected (66.6% significant disease).

Conclusion

A combination of MRI-targeted and template biopsy may optimally risk-classify “low-risk” patients diagnosed on initial conventional transrectal ultrasonography (TRUS) prostate biopsy.

Increasing detection of significant prostate cancer in younger men - ten year trends in prostate cancer risk profile in the Mid-West of Ireland

INTRODUCTION

Although PSA (prostate specific antigen) based screening for prostate cancer (PCa) is controversial, an increasing number of men are undergoing Transrectal Ultrasound Guided prostate biopsy (TRUSPB) through primary care-based PSA testing and referral to hospitals. The aim of our study was to investigate presenting risk profiles of PCa over the last decade in a cohort of men in Ireland and to examine any change in the same over this time period.

MATERIAL AND METHODS

The hospital patient administration system was analysed for patients who underwent TRUSPB from January 2005 to December 2015. Clinically significant PCa was defined as Gleason score of 7 or above.

RESULTS

Complete data was available on 2391 TRUSPB patients: number of biopsies increased by 53%, median age decreased by 0.9%, median PSA decreased by 6% (p = 0.001, ANOVA) and abnormal DRE increased by 9% (p = 0.001, chi square). Overall positive biopsy was 44% and significant cancer rate was 21%. There was a significant change in trend of detection (p = 0.02) with average annual increase in significant cancer of 3%. The median age of the significant cancer cohort reduced by 1% and the PSA at diagnosis reduced by 9%. In younger men (<50 years), the rate of significant cancer detection increased by 18%.

CONCLUSIONS

Significant PCa detection increased across all age groups but recently, a younger patient profile was diagnosed with high-grade disease. This paves the way for future research on early-onset PCa. Younger patients with significant disease would result in increasing number of patients being eligible for radical treatment with implications on health resource planning and provision.

Magnetic Resonance Imaging-Ultrasound Fusion-Guided Prostate Biopsy: Review of Technology, Techniques, and Outcomes

Transrectal ultrasound (TRUS)-guided (12-14 core) systematic biopsy of the prostate is the recommended standard for patients with suspicion of prostate cancer (PCa). Advances in imaging have led to the application of magnetic resonance imaging (MRI) for the detection of PCa with subsequent development of software-based co-registration allowing for the integration of MRI with real-time TRUS during prostate biopsy. A number of fusion-guided methods and platforms are now commercially available with common elements in image and analysis and planning. Implementation of fusion-guided prostate biopsy has now been proven to improve the detection of clinically significant PCa in appropriately selected patients.

A urologist's perspective on prostate cancer imaging: past, present, and future

Prostate cancer is unique in that unlike other solid organ malignancies, only recently has imaging been employed to routinely detect and localize disease. The introduction of transrectal ultrasound was a significant development, transitioning digitally guided prostate biopsies to ultrasound guidance. The arrival of multiparametric MRI has become the next major step, transforming the way Urologist's diagnose, stage, and treat prostate cancer. Recent recommendations against PSA screening have changed the landscape of urologic oncology with the changing needs being reflected in the initiation of additional robust imaging techniques at different time points in prostate cancer care. The current review aims to provide a clinical perspective in the history, current standard of care, and novel imaging modalities in the evaluation of prostate cancer.

Detection of Significant Prostate Cancer According to Anatomical Areas of Sampling Cores Obtained with Transrectal Systematic 12-Core Biopsy

BACKGROUND

To analyze the diagnostic performance of 12-core biopsy in detecting significant prostate cancer (PCa).

PATIENTS AND METHODS

Thisstudy included 206 PCa patients who underwent transrectal 12-core biopsy followed by radical prostatectomy. Radical prostatectomy specimens were anatomically divided into 12 areas according to the sampling cores, and the existence of significant cancer, defined by a tumor volume > 0.5 ml, was investigated. The detection rate of significant cancer in each area was calculated as follows: the number of positive core biopsies/the number of areas containing significant cancer × 100.

RESULTS

The overall detection rate of significant cancer in all areas was 53.6%. The detection rate was significantly higher in the standard sextant cores than in the additional 6 cores in patients with prostate-specific antigen ≥ 10 ng/ml, clinical stage ≥ T2, or biopsy Gleason score ≥ 7, but not in those with prostate-specific antigen < 10 ng/ml, clinical stage T1c, or biopsy Gleason score ≤ 6.

CONCLUSIONS

Approximately half of the significant cancers were not accurately detected, and the detection rates in biopsy cores other than the sextant cores appeared to be significantly lower in PCa patients with aggressive features.

The detection and upgrade rates of prostate adenocarcinoma following transperineal template-guided prostate biopsy - a tertiary referral centre experience

INTRODUCTION

We aim to present transperineal template-guided prostate biopsy (template biopsy) outcomes at a tertiary referral centre. Furthermore, to identify the detection rate of prostate cancer in those with a previous negative transrectal ultrasound guided prostate biopsy and the upgrade rate of those on active surveillance for Gleason 3 + 3 = 6 prostate adenocarcinoma.

MATERIAL AND METHODS

We conducted a prospective study of 200 consecutive men who underwent template biopsy over a 22-month period in a tertiary referral centre, using a standard 24 region template prostate biopsy technique. Indications and histology results, as well as complications, were recorded.

RESULTS

Median age was 67 years and median PSA was 10 ng/mL. Overall detection rate was 47%. 39.5% of cases with previous negative transrectal biopsies were found to have prostate adenocarcinoma. 47.5% of cases on active surveillance for Gleason 3 + 3 = 6 prostate adenocarcinoma were upgraded. The most frequent complication was acute urinary retention at a rate of 12.5%, however, the use of a single prophylactic dose of tamsulosin was found to be beneficial, with 13 cases needed to treat to prevent one episode.

CONCLUSIONS

Template biopsies are safe and efficacious with an overall detection rate of 47% in the present series. Due to the high detection rate, one must consider template biopsy following one negative transrectal biopsy where there is persistent clinical suspicion. Furthermore, those considering active surveillance for Gleason 3 + 3 = 6 disease should be offered template biopsy to confirm the grade of their disease.

The current and future role of magnetic resonance imaging in prostate cancer detection and management

Purpose

Accurate detection of clinically significant prostate cancer (PC) and correct risk attribution are essential to individually counsel men with PC. Multiparametric MRI (mpMRI) facilitates correct localization of index lesions within the prostate and MRI-targeted prostate biopsy (TPB) helps to avoid the shortcomings of conventional biopsy such as false-negative results or underdiagnosis of aggressive PC. In this review we summarize the different sequences of mpMRI, characterize the possibilities of incorporating MRI in the biopsy workflow and outline the performance of targeted and systematic cores in significant cancer detection. Furthermore, we outline the potential of MRI in patients undergoing active surveillance (AS) and in the pre-operative setting.

Materials and methods

An electronic MEDLINE/PubMed search up to February 2015 was performed. English language articles were reviewed for inclusion ability and data were extracted, analyzed and summarized.

Results

Targeted biopsies significantly outperform conventional systematic biopsies in the detection of significant PC and are not inferior when compared to transperineal saturation biopsies. MpMRI can detect index lesions in app. 90% of cases as compared to prostatectomy specimen. The diagnostic performance of biparametric MRI (T2w + DWI) is not inferior to mpMRI, offering options to diminish cost- and time-consumption. Since app 10% of significant lesions are still MRI-invisible, systematic cores seem to be necessary. In-bore biopsy and MRI/TRUS-fusion-guided biopsy tend to be superior techniques compared to cognitive fusion. In AS, mpMRI avoids underdetection of significant PC and confirms low-risk disease accurately. In higher-risk disease, pre-surgical MRI can change the clinically-based surgical plan in up to a third of cases.

Conclusions

mpMRI and targeted biopsies are able to detect significant PC accurately and mitigate insignificant PC detection. As long as the negative predictive value (NPV) is still imperfect, systematic cores should not be omitted for optimal staging of disease. The potential to correctly classify aggressiveness of disease in AS patients and to guide and plan prostatectomy is evolving.

Prostate calculi can higher urinary retention probability and worsen uncomfortable feeling after prostate biopsy but not predict cancer

To investigate whether prostatic calculi might influence the urinary retention (UR) probability, the quality of life (QOL) and the positive rate of cancer after prostate biopsy in middle-aged and old male with PSA higher than normal. This study comprised a retrospective analysis of data from 685 patients (prostatic calculi group 325 VS non-prostatic calculi group 360), those who had undergone transrectal ultrasound-guided prostate needle biopsy (TRUS PNB) from Sept. 2012 to Sept. 2014. To these people, prostate volumes (PV) were recorded by TRUS and prostatic calculi were defined as present or absent. Other variables such as age, International Prostate Symptoms Score (IPSS), the quality of life (QOL), total PSA (prostate specific antigen) rate, and urinary retention cases were also recorded and compared. Among these patients, 154 (prostatic calculi group 73 VS non-prostatic calculi group 81) were diagnosed with prostate cancer through postoperative pathological, there was no significant difference between the two groups. But compared to the non-prostatic calculi group, after the prostate biopsy, the group with prostatic calculi experienced more uncomfortable feelings and enjoyed higher Urinary retention probability. Prostatic calculi could worsen QOL and higher urinary retention probability after transrectal ultrasound-guided prostate needle biopsy, but it is a weak predictor of positive results of prostate cancer in middle-aged and old male with PSA higher than normal.

Computer aided-diagnosis of prostate cancer on multiparametric MRI: a technical review of current research

Prostate cancer (PCa) is the most commonly diagnosed cancer among men in the United States. In this paper, we survey computer aided-diagnosis (CADx) systems that use multiparametric magnetic resonance imaging (MP-MRI) for detection and diagnosis of prostate cancer. We review and list mainstream techniques that are commonly utilized in image segmentation, registration, feature extraction, and classification. The performances of 15 state-of-the-art prostate CADx systems are compared through the area under their receiver operating characteristic curves (AUC). Challenges and potential directions to further the research of prostate CADx are discussed in this paper. Further improvements should be investigated to make prostate CADx systems useful in clinical practice.

Standards for prostate biopsy

PURPOSE OF REVIEW

A variety of techniques have emerged for the optimization of prostate biopsy. In this review, we summarize and critically discuss the most recent developments regarding the optimal systematic biopsy and sampling labeling along with multiparametric MRI and magnetic resonance-targeted biopsies.

RECENT FINDINGS

The use of 10-12-core-extended sampling protocols increases cancer detection rates compared with traditional sextant sampling and reduces the likelihood that patients will require a repeat biopsy, ultimately allowing more accurate risk stratification without increasing the likelihood of detecting insignificant cancers. As the number of cores increases above 12 cores, the increase in diagnostic yield becomes marginal. However, the limitations of this technique include undersampling, oversampling, and the need for repetitive biopsy. MRI and magnetic resonance-targeted biopsies have demonstrated superiority over systematic biopsies for the detection of clinically significant disease and representation of disease burden, while deploying fewer cores and may have applications in men undergoing initial or repeat biopsy and those with low-risk cancer on or considering active surveillance.

SUMMARY

A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection, avoidance of a repeat biopsy while minimizing the detection of insignificant prostate cancers. MRI-guided prostate biopsy has an evolving role in both initial and repeat prostate biopsy strategies, as well as active surveillance, potentially improving sampling efficiency, increasing the detection of clinically significant cancers, and reducing the detection of insignificant cancers.

Optimization of prostate biopsy: the role of magnetic resonance imaging targeted biopsy in detection, localization and risk assessment

PURPOSE

Optimization of prostate biopsy requires addressing the shortcomings of standard systematic transrectal ultrasound guided biopsy, including false-negative rates, incorrect risk stratification, detection of clinically insignificant disease and the need for repeat biopsy. Magnetic resonance imaging is an evolving noninvasive imaging modality that increases the accurate localization of prostate cancer at the time of biopsy, and thereby enhances clinical risk assessment and improves the ability to appropriately counsel patients regarding therapy. In this review we 1) summarize the various sequences that comprise a prostate multiparametric magnetic resonance imaging examination along with its performance characteristics in cancer detection, localization and reporting standards; 2) evaluate potential applications of magnetic resonance imaging targeting in prostate biopsy among men with no previous biopsy, a negative previous biopsy and those with low stage cancer; and 3) describe the techniques of magnetic resonance imaging targeted biopsy and comparative study outcomes.

MATERIALS AND METHODS

A bibliographic search covering the period up to October 2013 was conducted using MEDLINE®/PubMed®. Articles were reviewed and categorized based on which of the 3 objectives of this review was addressed. Data were extracted, analyzed and summarized.

RESULTS

Multiparametric magnetic resonance imaging consists of anatomical T2-weighted imaging coupled with at least 2 functional imaging techniques. It has demonstrated improved prostate cancer detection sensitivity up to 80% in the peripheral zone and 81% in the transition zone. A prostate cancer magnetic resonance imaging suspicion score has been developed, and is depicted using the Likert or PI-RADS (Prostate Imaging Reporting and Data System) scale for better standardization of magnetic resonance imaging interpretation and reporting. Among men with no previous biopsy, magnetic resonance imaging increases the frequency of significant cancer detection to 50% in low risk and 71% in high risk patients. In low risk men the negative predictive value of a combination of negative magnetic resonance imaging with prostate volume parameters is nearly 98%, suggesting a potential role in avoiding biopsy and reducing over detection/overtreatment. Among men with a previous negative biopsy 72% to 87% of cancers detected by magnetic resonance imaging guidance are clinically significant. Among men with a known low risk cancer, repeat biopsy using magnetic resonance targeting demonstrates a high likelihood of confirming low risk disease in low suspicion score lesions and of upgrading in high suspicion score lesions. Techniques of magnetic resonance imaging targeted biopsy include visual estimation transrectal ultrasound guided biopsy; software co-registered magnetic resonance imaging-ultrasound, transrectal ultrasound guided biopsy; and in-bore magnetic resonance imaging guided biopsy. Although the improvement in accuracy and efficiency of visual estimation biopsy compared to systematic appears limited, co-registered magnetic resonance imaging-ultrasound biopsy as well as in-bore magnetic resonance imaging guided biopsy appear to increase cancer detection rates in conjunction with increasing suspicion score.

CONCLUSIONS

Use of magnetic resonance imaging for targeting prostate biopsies has the potential to reduce the sampling error associated with conventional biopsy by providing better disease localization and sampling. More accurate risk stratification through improved cancer sampling may impact therapeutic decision making. Optimal clinical application of magnetic resonance imaging targeted biopsy remains under investigation.

DNA methylation status is more reliable than gene expression at detecting cancer in prostate biopsy

Background:

We analysed critically the potential usefulness of RNA- and DNA-based biomarkers in supporting conventional histological diagnostic tests for prostate carcinoma (PCa) detection.

Methods:

Microarray profiling of gene expression and DNA methylation was performed on 16 benign prostatic hyperplasia (BPH) and 32 cancerous and non-cancerous prostate samples extracted by radical prostatectomy. The predictive value of the selected biomarkers was validated by qPCR-based methods using tissue samples extracted from the 58 prostates and, separately, using 227 prostate core biopsies.

Results:

HOXC6, AMACR and PCA3 expression showed the best discrimination between PCa and BPH. All three genes were previously reported as the most promising mRNA-based markers for distinguishing cancerous lesions from benign prostate lesions; however, none were sufficiently sensitive and specific to meet the criteria for a PCa diagnostic biomarker. By contrast, DNA methylation levels of the APC, TACC2, RARB, DGKZ and HES5 promoter regions achieved high discriminating sensitivity and specificity, with area under the curve (AUCs) reaching 0.95−1.0. Only a small overlap was detected between the DNA methylation levels of PCa-positive and PCa-negative needle biopsies, with AUCs ranging between 0.854 and 0.899.

Conclusions:

DNA methylation-based biomarkers reflect the prostate malignancy and might be useful in supporting clinical decisions for suspected PCa following an initial negative prostate biopsy.