Prognostic and predictive factors and reporting of prostate carcinoma in prostate needle biopsy specimens

The 2019 Genitourinary Pathology Society (GUPS) White Paper on Contemporary Grading of Prostate Cancer

CONTEXT.—

Controversies and uncertainty persist in prostate cancer grading.

OBJECTIVE.—

To update grading recommendations.

DATA SOURCES.—

Critical review of the literature along with pathology and clinician surveys.

CONCLUSIONS.—

Percent Gleason pattern 4 (%GP4) is as follows: (1) report %GP4 in needle biopsy with Grade Groups (GrGp) 2 and 3, and in needle biopsy on other parts (jars) of lower grade in cases with at least 1 part showing Gleason score (GS) 4 + 4 = 8; and (2) report %GP4: less than 5% or less than 10% and 10% increments thereafter. Tertiary grade patterns are as follows: (1) replace "tertiary grade pattern" in radical prostatectomy (RP) with "minor tertiary pattern 5 (TP5)," and only use in RP with GrGp 2 or 3 with less than 5% Gleason pattern 5; and (2) minor TP5 is noted along with the GS, with the GrGp based on the GS. Global score and magnetic resonance imaging (MRI)-targeted biopsies are as follows: (1) when multiple undesignated cores are taken from a single MRI-targeted lesion, an overall grade for that lesion is given as if all the involved cores were one long core; and (2) if providing a global score, when different scores are found in the standard and the MRI-targeted biopsy, give a single global score (factoring both the systematic standard and the MRI-targeted positive cores). Grade Groups are as follows: (1) Grade Groups (GrGp) is the terminology adopted by major world organizations; and (2) retain GS 3 + 5 = 8 in GrGp 4. Cribriform carcinoma is as follows: (1) report the presence or absence of cribriform glands in biopsy and RP with Gleason pattern 4 carcinoma. Intraductal carcinoma (IDC-P) is as follows: (1) report IDC-P in biopsy and RP; (2) use criteria based on dense cribriform glands (>50% of the gland is composed of epithelium relative to luminal spaces) and/or solid nests and/or marked pleomorphism/necrosis; (3) it is not necessary to perform basal cell immunostains on biopsy and RP to identify IDC-P if the results would not change the overall (highest) GS/GrGp part per case; (4) do not include IDC-P in determining the final GS/GrGp on biopsy and/or RP; and (5) "atypical intraductal proliferation (AIP)" is preferred for an intraductal proliferation of prostatic secretory cells which shows a greater degree of architectural complexity and/or cytological atypia than typical high-grade prostatic intraepithelial neoplasia, yet falling short of the strict diagnostic threshold for IDC-P. Molecular testing is as follows: (1) Ki67 is not ready for routine clinical use; (2) additional studies of active surveillance cohorts are needed to establish the utility of PTEN in this setting; and (3) dedicated studies of RNA-based assays in active surveillance populations are needed to substantiate the utility of these expensive tests in this setting. Artificial intelligence and novel grading schema are as follows: (1) incorporating reactive stromal grade, percent GP4, minor tertiary GP5, and cribriform/intraductal carcinoma are not ready for adoption in current practice.

Atypical small acinar proliferation and its significance in pathological reports in modern urological times

Atypical small acinar proliferation is a histopathological diagnosis of unspecified importance in prostate needle-biopsy reports, suggestive but not definitive for cancer. The terminology corresponds to some uncertainty in the biopsy report, as the finding might represent an underlying non-cancerous pathology mimicking cancer or an under-sampled prostate cancer site. Therefore, traditional practice favors an immediate repeat biopsy. However, in modern urological times, the need of urgent repeat biopsy is being challenged by some authors as in the majority of cases, the grade of cancer found in subsequent biopsy is reported to be low or the disease to be non-significant. On the other hand, high risk disease cannot be excluded, whereas no clinical or pathological factors can predict the final outcome. In this review, we discuss the significance of the diagnosis of atypical small acinar proliferation in the biopsy report, commenting on its importance in modern urological practice.

Prediction of prostate cancer Gleason score upgrading from biopsy to radical prostatectomy using pre-biopsy multiparametric MRI PIRADS scoring system

An increase or ‘upgrade’ in Gleason Score (GS) in prostate cancer following Transrectal Ultrasound (TRUS) guided biopsies remains a significant challenge to overcome. to evaluate whether MRI has the potential to narrow the discrepancy of histopathological grades between biopsy and radical prostatectomy, three hundred and thirty men treated consecutively by laparoscopic radical prostatectomy (LRP) between July 2014 and January 2019 with localized prostate cancer were included in this study. Independent radiologists and pathologists assessed the MRI and histopathology of the biopsies and prostatectomy specimens respectively. A multivariate model was constructed using logistic regression analysis to assess the ability of MRI to predict upgrading in biopsy GS in a nomogram. A decision-analysis curve was constructed assessing impact of nomogram using different thresholds for probabilities of upgrading. PIRADS scores were obtained from MRI scans in all the included cases. In a multivariate analysis, the PIRADS v2.0 score significantly improved prediction ability of MRI scans for upgrading of biopsy GS (p = 0.001, 95% CI [0.06–0.034]), which improved the C-index of predictive nomogram significantly (0.90 vs. 0.64, p < 0.05). PIRADS v2.0 score was an independent predictor of postoperative GS upgrading and this should be taken into consideration while offering treatment options to men with localized prostate cancer.

Can epigenetic and inflammatory biomarkers identify clinically aggressive prostate cancer?

Prostate cancer (PCa) is a highly prevalent malignancy and constitutes a major cause of cancer-related morbidity and mortality. It emerges through the acquisition of genetic and epigenetic alterations. Epigenetic modifications include DNA methylation, histone modifications and microRNA deregulation. These generate heritable transformations in the expression of genes but do not change the DNA sequence. Alterations in DNA methylation (hypo and hypermethylation) are the most characterized in PCa. They lead to genomic instability and inadequate gene expression. Major and minor-specific modifications in chromatin recasting are involved in PCa, with signs suggesting a dysfunction of enzymes modified by histones. MicroRNA deregulation also contributes to the initiation of PCa, including involvement in androgen receptor signalization and apoptosis. The influence of inflammation on prostate tumor carcinogenesis is currently much better known. Recent discoveries about microbial species resident in the urinary tract suggest that these are the initiators of chronic inflammation, promoting prostate inflammatory atrophy and eventually leading to PCa. Complete characterization of the relationship between the urinary microbiome and prostatic chronic inflammation will be crucial to develop plans for the prevention of PCa. The prevalent nature of epigenetic and inflammatory alterations may provide potential biomarkers for PCa diagnosis, treatment decisions, evaluation of prognosis and posttreatment surveillance.

Diagnostic, prognostic and predictive parameters in prostate cancer

Prostate cancer (CP) is the most common malignancy in men in America, while it is the second most common in Europe. It is responsible for about 10% of cancer deaths in the same population. It is clinically manifested in various forms, from slow-growing to aggressive forms with pronounced metastatic potential. Diagnosis is made by a well-defined algorithm, which begins with the determination of serum prostate specific antigen values and ends with prostate biopsy as the "gold standard". Pathohistological diagnostic criterias are based on architectural, cytoplasmic, nuclear and characteristics of intraluminal structures, as well as periacinar cleftings, which are deffined as helpfull diagnostic criteria of undoubted importance. Prognostic and predictive parameters are classified into three categories. Some of them are an integral part of routine pathohistologicat report, while others are considered as the diagnostic process progresses. Modern knowledge introduces biomarkers into the everyday practice of personalized medicine, especially when is necessary to treat prostate cancer patients.

Prostatic Adenocarcinoma: A Grading from Gleason to the New Grade-Group System: A Historical and Critical Review

The introduction of the Gleason grading system revolutionised prognostic parameters and determination of patient treatment regiments for prostatic adenocarcinomas, and has become synonymous with prostate cancer, almost universally applied in clinical settings to predict radical prostatectomy specimen findings, potential biochemical failure, local recurrences, lymph nodes or distant metastases in patients not receiving any treatment as well as those receiving treatment including radiation therapy, surgical treatment such as radical prostatectomy and other therapies etc,. However, characterisation and classification of prostate cancer is very different compared to 40-50 years ago when Gleason scores were first introduced. Despite this radical shift in classification, the Gleason system has remained one of the most important prognostic factors in prostate cancer, only possible as a result of timely and appropriate modifications to this characterisation system made in 2005 and 2014. However, even after these modifications, certain limitations of the Gleason system remain, due to which a new prostate cancer prognostic grade group system was introduced in 2014, which was widely accepted in the 2014 ISUP consensus conference, and incorporated into the WHO classification of thetumor of the Urinary System and Male Genital Tract in 2016. Herein, this article will discuss how this new prognostic grade group system, which is regarded as simpler and more accurate than the Gleason system risk stratification groups, will be used in conjunction with the Gleason system to improve patient prognosis and treatment.

Evolution, controversies and the future of prostate cancer grading

Histological grading of prostate cancer is one of the most important tissue-based parameters for prediction of outcome and treatment response. Gleason grading remains the foundation of prostate cancer grading, but has undergone a series of changes in the past 30 years, often initiated by consensus conference decisions. This review summarizes the most important modifications that were introduced by the 2005 and 2014 International Society of Urological Pathology (ISUP) revisions of Gleason grading and discusses the impact that these have had on current grading practices. A considerable inflation in Gleason scores has been observed, especially following the ISUP 2005 revision, and the effects of this are discussed. ISUP 2014 grading recommendations are described, including the reporting of ISUP grades 1-5. Controversial issues include methods for reporting of grades on needle biopsies, reporting of percent Gleason grades 4/5 and grading of cribriform and intraductal carcinoma of the prostate. Educational programs developed recently to promote standardization of grading are described and their results assessed.

Quality indicators of clinical cancer care for prostate cancer: a population-based study in southern Switzerland

Background

Quality of cancer care (QoCC) has become an important item for providers, regulators and purchasers of care worldwide. Aim of this study is to present the results of some evidence-based quality indicators (QI) for prostate cancer (PC) at the population-based level and to compare the outcomes with data available in the literature.

Methods

The study included all PC diagnosed on a three years period analysis (01.01.2011–31.12.2013) in the population of Canton Ticino (Southern Switzerland) extracted from the Ticino Cancer Registry database. 13 QI, approved through the validated Delphi methodology, were calculated using the “available case” approach: 2 for diagnosis, 4 for pathology, 6 for treatment and 1 for outcome. The selection of the computed QI was based on the availability of medical documentation. QI are presented as proportion (%) with the corresponding 95% confidence interval.

Results

700 PC were detected during the three-year period 2011–2013: 78.3% of them were diagnosed through a prostatic biopsy and for 72.5% 8 or more biopsy cores were taken. 46.5% of the low risk PC patients underwent active surveillance, while 69.2% of high risk PC underwent a radical treatment (radical prostatectomy, radiotherapy or brachytherapy) and 73.5% of patients with metastatic PC were treated with hormonal therapy. The overall 30-day postoperative mortality was 0.5%.

Conclusions

Results emerging from this study on the QoCC for PC in Canton Ticino are encouraging: the choice of treatment modalities seems to respect the international guidelines and our results are comparable to the scarce number of available international studies. Additional national and international standardisation of the QI and further QI population-based studies are needed in order to get a real picture of the PC diagnostic-therapeutic process progress through the definition of thresholds of minimal standard of care.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4604-2) contains supplementary material, which is available to authorized users.

Access to pathology and laboratory medicine services: a crucial gap

As global efforts accelerate to implement the Sustainable Development Goals and, in particular, universal health coverage, access to high-quality and timely pathology and laboratory medicine (PALM) services will be needed to support health-care systems that are tasked with achieving these goals. This access will be most challenging to achieve in low-income and middle-income countries (LMICs), which have a disproportionately large share of the global burden of disease but a disproportionately low share of global health-care resources, particularly PALM services. In this first in a Series of three papers on PALM in LMICs, we describe the crucial and central roles of PALM services in the accurate diagnosis and detection of disease, informing prognosis and guiding treatment, contributing to disease screening, public health surveillance and disease registries, and supporting medical-legal systems. We also describe how, even though data are sparse, these services are of both insufficient scope and inadequate quality to play their key role in health-care systems in LMICs. Lastly, we identify four key barriers to the provision of optimal PALM services in resource-limited settings: insufficient human resources or workforce capacity, inadequate education and training, inadequate infrastructure, and insufficient quality, standards, and accreditation.

Typing the atypical: Diagnostic issues and predictive markers in suspicious prostate lesions

As much as 5% of prostate biopsies yield findings equivocal for malignancy even for skilled uropathologist; such "grey zone" lesions have been addressed in many ways, although the acronym ASAP (atypical small acinar proliferation) is the most widely used when referring to an atypical focus suspicious, but not diagnostic, for malignancy. Since the introduction of this diagnostic category more than 20 years ago, debate has ensued over its histological characterization and clinical significance. Pathology reporting of ASAP, commonly based on strict morphological criteria and traditional immunohistochemical markers such as basal cell antibodies, has been improved by recent availability of novel immunohistochemical markers such as AMACR and ERG. Further pathological issues, such as the role of pre-analytical variables, number of tissue levels, interobserver variability, and association with prostatic intraepithelial neoplasia also play a role in the optimal assessment of ASAP. Apart from diagnostic issues, a major issue is ASAP predictive value for prostate cancer on repeat biopsy. Therefore, attempts have been made to identify clinical and biological parameters that could predict subsequent diagnosis of malignancy as well as define time and modality of repeat biopsy. Finally, pathological features of cancers detected after a previous ASAP diagnosis are compared with those diagnosed at first prostate biopsy.

Prostate cancer diagnosis using epigenetic biomarkers, 3D high-content imaging and probabilistic cell-by-cell classifiers

Background

Prostate cancer (PCa) management can benefit from novel concepts/biomarkers for reducing the current 20-30% chance of false-negative diagnosis with standard histopathology of biopsied tissue.

Method

We explored the potential of selected epigenetic markers in combination with validated histopathological markers, 3D high-content imaging, cell-by-cell analysis, and probabilistic classification in generating novel detailed maps of biomarker heterogeneity in patient tissues, and PCa diagnosis. We used consecutive biopsies/radical prostatectomies from five patients for building a database of ∼140,000 analyzed cells across all tissue compartments and for model development; and from five patients and the two well-characterized HPrEpiC primary and LNCaP cancer cell types for model validation.

Results

Principal component analysis presented highest covariability for the four biomarkers 4′,6-diamidino-2-phenylindole, 5-methylcytosine, 5-hydroxymethylcytosine, and alpha-methylacyl-CoA racemase in the epithelial tissue compartment. The panel also showed best performance in discriminating between normal and cancer-like cells in prostate tissues with a sensitivity and specificity of 85%, correctly classified 87% of HPrEpiC as healthy and 99% of LNCaP cells as cancer-like, identified a majority of aberrant cells within histopathologically benign tissues at baseline diagnosis of patients that were later diagnosed with adenocarcinoma. Using k-nearest neighbor classifier with cells from an initial patient biopsy, the biomarkers were able to predict cancer stage and grade of prostatic tissue that occurred at later prostatectomy with 79% accuracy.

Conclusion

Our approach showed favorable diagnostic values to identify the portion and pathological category of aberrant cells in a small subset of sampled tissue cells, correlating with the degree of malignancy beyond baseline.

Prostate cancer: from Gleason scoring to prognostic grade grouping

The Gleason grading system was developed in the late 1960s by Dr. Donald F. Gleason. Due to changes in prostatic adenocarcinoma (PAC) detection and treatment, newer technologies to better characterize prostatic pathology, subsequently described variants of PAC and further data relating various morphologic patterns to prognosis, the application of the Gleason grading system changed substantially in surgical pathology. First in 2005 and more recently in 2014, consensus conferences were held to update PAC grading. Here, we review of the successive changes in the grading of PAC from the original system, with emphasis on the newest prognostic grade grouping.

Gleason group concordance between biopsy and radical prostatectomy specimens: A cohort study from Prostate Cancer Outcome Registry - Victoria

Background

A new prostate cancer (PCa) prognostic grading system [Gleason groups (GGs)] has been proposed based on the contemporary Gleason scores (GSs), which has five simplified prognostic categories. The objective of this study was to evaluate the agreement between the GGs of prostate biopsy and radical prostatectomy specimens and to identify predictive factors for upgrading GGs.

Methods

A total of 5339 cases of RP notified to the Prostate Cancer Outcomes Registry, Victoria, Australia over 6 years (2009–2014) from 46 hospitals, were included. The upgrading was evaluated using the new PCa prognostic grading system, the International Society of Urologic Pathology grade groups, which has five prognostic categories. GG 1 is GS ≤ 6, GG 2 is GS 3 + 4 = 7, GG 3 is GS 4 + 3 = 7, GG 4 is GS 8, and GG 5 is GS 9 and 10. Predictors of upgrading were assessed using univariate and multivariate models.

Results

The GG of prostate biopsies and RP specimens were concordant in 54.5% of cases, while 31.1% were upgraded and 14.3% were downgraded. Longer time interval between biopsy and RP [44–99 days: odds ratio (OR) = 1.3, 95% confidence interval (CI) = 1.1–1.6; > 99 days: OR = 3.0, 95% CI = 2.4–3.8), and RP performed in a metropolitan hospital (biopsy in a regional hospital: OR = 2.2, 95% CI = 1.6–3.2, biopsy in a metropolitan hospital: OR = 1.7, 95% CI = 1.2–2.2) were significant predictors of GG upgrading. Patients who were diagnosed by transperineal biopsy compared to transrectal ultrasound (OR = 0.6, 95% CI = 0.5–0.8) and higher percentage of positive biopsy cassettes (25–62.5%: OR = 0.7, 95% CI = 0.6–0.8, > 62.5: OR = 0.6, 95% CI = 0.5–0.8) were significantly associated with less likelihood of upgrade.

Conclusion

The lack of concordance among hospitals may be attributable to the specialist expertise of the pathologist. Expert review of specimens may help to overcome this discordance. Clinicians should consider clinical parameters and potential limitations of the GG at biopsy when making treatment decisions with regard to PCa.

Molecular Updates in Prostate Cancer

A wide array of molecular markers and genomic signatures, reviewed in this article, may soon be used as adjuncts to currently established screening strategies, prognostic parameters, and early detection markers. Markers of genetic susceptibility to PCA, recurrent epigenetic and genetic alterations, including ETS gene fusions, PTEN alterations, and urine-based early detection marker PCA3, are discussed. Impact of recent genome-wide assessment on our understanding of key pathways of PCA development and progression and their potential clinical implications are highlighted.

Expression of proinflammatory cytokine interleukin-6 in tissue samples of human prostate obtained by needle biopsy

Interleukin-6 (IL-6) has been associated with the development of prostate cancer. The aim of the study was to clarify whether IL-6 expression in prostate tissue could be a useful marker in differentiation of prostate diseases in small foci by pathologist visual scoring. Archival paraffin-embedded specimens of benign prostate hyperplasia (BPH), high-grade prostatic intraepithelial neoplasia (PIN), prostatitis and prostate adenocarcinoma were studied by immunohistochemistry with a mouse monoclonal antibody IL-6 using the streptavidin-biotin method. Significantly, lower IL-6 immunoreactivity was observed in normal epithelial cells (p=0.000) and basal cells (p=0.000) in the samples of prostate adenocarcinoma in comparison to the samples with BPH, PIN and prostatitis. There was no significant difference in IL-6 expression in malignant and premalignant cells (p=0.814) as well as in stromal cells among the four diagnoses (p=0.22). IL-6 was expressed in normal epithelial cells, premalignant epithelial cells and malignant epithelial cells as well as in stromal cells. However, in our research IL-6 was of limited utility as a single marker for differential diagnosis of the prostate diseases in small foci needle biopsy by pathologist visual scoring. The standardization of immunohistochemical (IHC) staining protocol for IL-6 is required to determine IL-6 expression in order to avoid possible misinterpretation of the IHC results.

The critical role of the pathologist in determining eligibility for active surveillance as a management option in patients with prostate cancer: consensus statement with recommendations supported by the College of American Pathologists, International Society of Urological Pathology, Association of Directors of Anatomic and Surgical Pathology, the New Zealand Society of Pathologists, and the Prostate Cancer Foundation

CONTEXT

Prostate cancer remains a significant public health problem. Recent publications of randomized trials and the US Preventive Services Task Force recommendations have drawn attention to overtreatment of localized, low-risk prostate cancer. Active surveillance, in which patients undergo regular visits with serum prostate-specific antigen tests and repeat prostate biopsies, rather than aggressive treatment with curative intent, may address overtreatment of low-risk prostate cancer. It is apparent that a greater awareness of the critical role of pathologists in determining eligibility for active surveillance is needed.

OBJECTIVES

To review the state of current knowledge about the role of active surveillance in the management of prostate cancer and to provide a multidisciplinary report focusing on pathologic parameters important to the successful identification of patients likely to succeed with active surveillance, to determine the role of molecular tests in increasing the safety of active surveillance, and to provide future directions.

DESIGN

Systematic review of literature on active surveillance for low-risk prostate cancer, pathologic parameters important for appropriate stratification, and issues regarding interobserver reproducibility. Expert panels were created to delineate the fundamental questions confronting the clinical and pathologic aspects of management of men on active surveillance.

RESULTS

Expert panelists identified pathologic parameters important for management and the related diagnostic and reporting issues. Consensus recommendations were generated where appropriate.

CONCLUSIONS

Active surveillance is an important management option for men with low-risk prostate cancer. Vital to this process is the critical role pathologic parameters have in identifying appropriate candidates for active surveillance. These findings need to be reproducible and consistently reported by surgical pathologists with accurate pathology reporting.

The association of the cribriform pattern with outcome for prostatic adenocarcinomas

With the revision of the Gleason system at the 2005 International Society of Urological Pathology Consensus Conference, there was consensus that most cribriform glands should be classified as pattern 4. There is now increased understanding that invasive cribriform carcinoma is a relatively aggressive disease. This study was based on 233 radical prostatectomy (RP) specimens collected at the Department of Pathology, Umraniye Education and Research Hospital, from 2006 to 2013. We assessed the cribriform foci associated with the more definitive patterns 3, 4, and 5 elsewhere on the RP specimens and evaluated the association of the presence of cribriform pattern (CP) with biochemical prostate-specific antigen recurrence (BPR). In Cox regression model, taking into account the Gleason score (GS), pathologic stage, surgical margin (SM) status, presence of a CP, and preoperative prostate-specific antigen (PSA), a positive SM, and the presence of a CP were independent predictors of BPR after RP. We observed BPR more frequently in GS 3+3 cases with a CP than in those without a CP (p=0.008). There was no significant difference in BPR status for cases with GS 3+4, 4+3, 4+5, and 5+4 when the patients were stratified by the presence of a CP. On the basis of these data, we suggest that the classification of CP into Gleason pattern 4 has value in predicting BPR status after RP. However, as many of these modifications are empirical and supported by only a few studies, long-term follow-up studies with clinical endpoints are necessary to validate these recommendations.

Fragmentation of transrectal ultrasound-guided biopsy cores is influenced by the method of specimen retrieval

OBJECTIVE

To determine whether the method of specimen preparation after transrectal ultrasound-guided biopsy of the prostate affected core fragmentation, and secondly to determine whether such fragmentation was influenced by the presence of malignancy in the biopsy specimen.

METHODS

A prospective randomized study comparing 2 different mechanisms of specimen preparation, wash vs swipe of biopsy cores, with blinded assessment by a specific uropathologist was undertaken.

RESULTS

For those cores in which prostate cancer was present, the wash method of specimen preparation resulted in fewer and longer core fragments (P = .005). Those patients in whom cancer was present on biopsy also had a greater degree of biopsy core fragmentation in those cores in which only benign tissue was identified (P = .017). Gleason score did not appear to influence the extent of fragmentation.

CONCLUSION

The method of specimen preparation at prostate biopsy influences the degree of fragmentation seen at histologic evaluation. This has the potential to affect the interpretation of biopsy results, including suitability of patients for inclusion in active surveillance protocols. Core fragmentation might be minimized by modification of technique.

Multidimensional MR spectroscopic imaging of prostate cancer in vivo

Prostate cancer (PCa) is the second most common type of cancer among men in the United States. A major limitation in the management of PCa is an inability to distinguish, early on, cancers that will progress and become life threatening. One-dimensional (1D) proton ((1)H) MRS of the prostate provides metabolic information such as levels of choline (Ch), creatine (Cr), citrate (Cit), and spermine (Spm) that can be used to detect and diagnose PCa. Ex vivo high-resolution magic angle spinning (HR-MAS) of PCa specimens has revealed detection of more metabolites such as myo-inositol (mI), glutamate (Glu), and glutamine (Gln). Due to the J-modulation and signal overlap, it is difficult to quantitate Spm and other resonances in the prostate clearly by single- and multivoxel-based 1D MR spectroscopy. This limitation can be minimized by adding at least one more spectral dimension by which resonances can be spread apart, thereby increasing the spectral dispersion. However, recording of multivoxel-based two-dimensional (2D) MRS such as J-resolved spectroscopy (JPRESS) and correlated spectroscopy (L-COSY) combined with 2D or three-dimensional (3D) magnetic resonance spectroscopic imaging (MRSI) using conventional phase-encoding can be prohibitively long to be included in a clinical protocol. To reduce the long acquisition time required for spatial encoding, the echo-planar spectroscopic imaging (EPSI) technique has been combined with correlated spectroscopy to give four-dimensional (4D) echo-planar correlated spectroscopic imaging (EP-COSI) as well as J-resolved spectroscopic imaging (EP-JRESI) and the multi-echo (ME) variants. Further acceleration can be achieved using non-uniform undersampling (NUS) and reconstruction using compressed sensing (CS). Earlier versions of 2D MRS, theory of 2D MRS, spectral apodization filters, newer developments and the potential role of multidimensional MRS in PCa detection and management will be reviewed here.

Clinical applications of recent molecular advances in urologic malignancies: no longer chasing a "mirage"?

As our understanding of the molecular events leading to the development and progression of genitourologic malignancies, new markers of detection, prognostication, and therapy prediction can be exploited in the management of these prevalent tumors. The current review discusses the recent advances in prostate, bladder, renal, and testicular neoplasms that are pertinent to the anatomic pathologist.

Current routines for transrectal ultrasound-guided prostate biopsy: a web-based survey by the Swedish Urology Network

OBJECTIVE

This study aimed to survey current Swedish practices for performing and handling transrectal ultrasound-guided prostate biopsies.

MATERIAL AND METHODS

A Swedish Urology Network (SUNe) was organized for the distribution of information, survey studies and research collaborations. A web-based questionnaire was distributed to the members in 2011.

RESULTS

In this first SUNe survey, 137 (91%) of the 151 members replied. All used antibiotic prophylaxis (84% ciprofloxacin, 12% trimethoprim-sulfamethoxazole), most commonly (63%) as a single dose of ciprofloxacin. Local anaesthesia was used by 87%. Half of the respondents only used a "side-fire" probe, whereas 17% always used an "end-fire" probe. Most (84%) routinely took 10 or more biopsy cores. About three-quarters started with the right base of the prostate and did not routinely take midline biopsies. More than one-third never or rarely sampled the anterior part of the prostate. There was great variability in how biopsy location was reported, but 71% considered a national standardized coordinate system desirable. Fine-needle aspiration was used occasionally by 39%, in more than 10% of cases by 6% and always by 2%. Most urologists mounted the biopsy cores on paper before fixation (78%), put only one core per jar (75%) and used flat-bottomed jars (70%).

CONCLUSIONS

Most routines for handling of prostate biopsies, antibiotic prophylaxis, local anaesthesia and number of cores were uniform. However, there is still a need for standardization of the performance of ultrasound-guided biopsies. Although the method used to specify biopsy location varied greatly, most urologists would prefer a national standardized system.

Emerging critical role of molecular testing in diagnostic genitourinary pathology

CONTEXT

The unprecedented advances in cancer genetics and genomics are rapidly affecting clinical management and diagnostics in solid tumor oncology. Molecular diagnostics is now an integral part of routine clinical management in patients with lung, colon, and breast cancer. In sharp contrast, molecular biomarkers have been largely excluded from current management algorithms of urologic malignancies.

OBJECTIVE

To discuss promising candidate biomarkers that may soon make their transition to the realm of clinical management of genitourologic malignancies. The need for new treatment alternatives that can improve upon the modest outcome so far in patients with several types of urologic cancer is evident. Well-validated prognostic molecular biomarkers that can help clinicians identify patients in need of early aggressive management are lacking. Identifying robust predictive biomarkers that will stratify response to emerging targeted therapeutics is another crucially needed development. A compiled review of salient studies addressing the topic could be helpful in focusing future efforts.

DATA SOURCES

A PubMed (US National Library of Medicine) search for published studies with the following search terms was conducted: molecular , prognostic , targeted therapy , genomics , theranostics and urinary bladder cancer , prostate adenocarcinoma , and renal cell carcinoma . Articles with large cohorts and multivariate analyses were given preference.

CONCLUSIONS

Our recent understanding of the complex molecular alterations involved in the development and progression of urologic malignancies is yielding novel diagnostic and prognostic molecular tools and opening the doors for experimental targeted therapies for these prevalent, frequently lethal solid tumors.

Implications of the International Society of Urological Pathology modified Gleason grading system

CONTEXT

Histologic grading is the clinically most useful tissue-based predictor of prognosis for prostate cancer. Over the years, there has been a gradual shift in how the Gleason grading is applied in practice, with a general trend toward upgrading. A consensus conference was organized in 2005 by the International Society of Urological Pathology (ISUP) for standardizing both the perception of histologic patterns and how the grade information is compiled and reported.

OBJECTIVE

To review the implications of the ISUP modified Gleason grading system.

DATA SOURCES

Personal experience and review of the current literature.

CONCLUSIONS

The recommendations regarding pattern interpretation and reporting are summarized. The practical consequences of the ISUP modification of the Gleason grading are reported. The prognostic importance of the Gleason score, its reproducibility, and its preoperative assessment are discussed. Subsequent proposals for slight modifications to the ISUP grading system are described.

Improved differentiation between ductal and acinar prostate cancer using three-dimensional histology and biomarkers

OBJECTIVE

The aim of the study was to refine the methodology for discriminating the ductal (DAP) and acinar adenocarcinomas (AAP) of the prostate and confirm that prostate carcinoma of ductal origin is a more aggressive subtype.

MATERIAL AND METHODS

A retrospective analysis of 110 consecutive radical prostatectomy cases operated on between 2000 and 2006 and worked up using large-format "two-dimensional" (2D; 4 μm thick) and "three-dimensional" (3D; 1500 μm thick) histology sections was carried out, with an average follow-up of 5.1 years. The same material was also analysed for selected biomarkers in tissue microarray blocks. The most discriminatory biomarkers were then tested on preoperative core biopsy specimens from 24 of these patients.

RESULTS

3D histology classified 97/110 (88%) cases of AAP and 13/110 (12%) DAP, which was then confirmed in 2D specimens. The DAP cases had a significantly greater frequency of pT3a and more advanced cancers, > 20 mm tumour focus, high-grade prostatic intraepithelial neoplasia, Gleason score ≥ 7, positive margin, extracapsular extension, vascular invasion, seminal vesicle infiltration, biochemical/local recurrence, regional lymph-node metastases and distant metastases. Three biomarkers in combination (chromogranin A, epidermal growth factor receptor and p53] distinguished DAP from AAP with an accuracy of 94% (area under the curve 0.94, 95% confidence interval 0.88-0.99). The same high accuracy was achieved using these three biomarkers on the preoperative specimens.

CONCLUSIONS

Both 3D histology and the three selected biomarkers can help in accurately distinguishing DAP from AAP. The clear-cut distinction of two forms of prostate cancers by the approach advocated in this paper would allow AAP patients to undergo less radical treatment and would segregate DAP patients into a subset requiring more effective treatment regimens.

Low endoglin vascular density and Ki67 index in Gleason score 6 tumours may identify prostate cancer patients suitable for surveillance

OBJECTIVE

The aim of this study was to explore whether vascular density and tumour cell proliferation are related to the risk of prostate cancer death in patients managed by watchful waiting.

MATERIAL AND METHODS

From a consecutive series of men diagnosed with prostate cancer at transurethral resection in 1975-1990, tissue microarrays (TMAs) were constructed. A majority of men had no metastases at diagnosis and were followed by watchful waiting (n = 295). The TMAs were stained for Ki67, endoglin and factor VIII-related antigen (vWf).

RESULTS

In univariate Cox analyses, increased Ki67 index, endoglin vascular density and vWf vascular density were associated with shorter cancer-specific survival. Ki67 index and endoglin vascular density added independent prognostic information to clinical stage, estimated tumour size and Gleason score (GS) in multivariate Cox analysis. In GS 6 tumours, high Ki67 index and high endoglin vascular density identified patients with poor outcome. After 15 years of follow-up not a single man out of 34 men with low staining for both markers (35% of all GS 6 tumours) had died of prostate cancer, in contrast to 15 prostate cancer deaths among the remaining 63 men with GS 6 tumours (65% cumulative risk of prostate cancer death). vWf vascular density in benign areas was a prognostic marker in GS 6 and 7 tumours.

CONCLUSIONS

Men with GS 6 tumours with both low Ki67 index and endoglin vascular density staining scores have a low risk of progression. Additional studies are needed to test whether these two markers can be applied to core biopsies to select patients suitable for surveillance.

Classifying prostate cancer malignancy by quantitative histomorphometry

PURPOSE

Prostate cancer is routinely graded according to the Gleason grading scheme. This scheme is predominantly based on the textural appearance of aberrant glandular structures. Gleason grade is difficult to standardize and often leads to discussion due to interrater and intrarater disagreement. Thus, we investigated whether digital image based automated quantitative histomorphometry could be used to achieve a more standardized, reproducible classification outcome.

MATERIALS AND METHODS

In a proof of principle study we developed a method to evaluate digitized histological images of single prostate cancer regions in hematoxylin and eosin stained sections. Preprocessed color images were subjected to color deconvolution, followed by the binarization of obtained hematoxylin related image channels. Highlighted neoplastic epithelial gland related objects were morphometrically assessed by a classifier based on 2 calculated quantitative and objective geometric measures, that is inverse solidity and inverse compactness. The procedure was then applied to the prostate cancer probes of 125 patients. Each probe was independently classified for Gleason grade 3, 4 or 5 by an experienced pathologist blinded to image analysis outcome.

RESULTS

Together inverse compactness and inverse solidity were adequate discriminatory features for a powerful classifier that distinguished Gleason grade 3 from grade 4/5 histology. The classifier was robust on sensitivity analysis.

CONCLUSIONS

Results suggest that quantitative and interpretable measures can be obtained from image based analysis, permitting algorithmic differentiation of prostate Gleason grades. The method must be validated in a large independent series of specimens.

Prognostic significance of neuroendocrine differentiation in prostate adenocarcinoma

Much progress has been made toward an understanding of the development and progression of prostate cancer (PC) and the factors that drive the development of androgen independence. Neuroendocrine (NE) cells may provide an intriguing link between NE cell differentiation (NED) and tumor progression in PC. NED in PC generally confers a more aggressive clinical behavior and less favorable prognosis than conventional PC. In this article, we review the known functions of NE cells in PC and discuss the current knowledge on stimulation of cancer proliferation, invasion, apoptosis resistance, serum and immunohistochemical markers, and the prognostic significance of NED in human PC.

Immunohistochemical verification of ductal differentiation in prostate cancer

Recent studies have shown that patients with prostate carcinomas exhibiting ductal differentiation have an unfavourable prognosis compared with those with purely acinar adenocarcinomas. We studied the expression of nine immunohistochemical markers to evaluate their value in delineating carcinomas with and without ductal differentiation. Thirteen tumours showing cellular characteristics and growth patterns typical of ductal differentiation were identified among 110 analysed prostatectomy specimens. The levels of cytoplasmic expression of chromogranine A (69% vs 19%, p = 0.0003) and nuclear expression of p53 (76% vs 12%, p < 0.0001) as well as nuclear expression of Ki-67 (69% vs 26%, p = 0.0047) in the tumour cells, were found to be statistically significantly different in the two tumour categories. Assessment of chromogranine A, p53 and Ki-67 in prostate carcinoma may serve as useful adjunctive diagnostic tools for delineating more aggressive prostate cancer cases exhibiting ductal differentiation.

Significance of atypical small acinar proliferation and high-grade prostatic intraepithelial neoplasia in prostate biopsy

Purpose

In clinical practice, atypical small acinar proliferation (ASAP) and high-grade prostatic intraepithelial neoplasia (HGPIN) are two common findings on prostate biopsies. Knowing the frequency of a prostate cancer diagnosis on repeat biopsies would aid primary treating physicians regarding their decisions in suspicious cases.

Materials and Methods

One hundred forty-three patients in whom biopsies revealed ASAP or HGPIN or both were enrolled in the present study; prostate cancer was not reported in the biopsy specimens and at least one repeat biopsy was performed. Age, digital rectal examination findings, prostate volumes, and free and total prostate-specific antigen (PSA) levels and the biopsy results of the patients were recorded.

Results

Of the 97 patients with ASAP on the first set of biopsies, prostate cancer was diagnosed in the second and third biopsies of 32 and 6 patients, respectively. Prostate cancer was not detected in the second or third biopsies of the 40 patients with HGPIN in the first biopsy. Of the 6 patients with ASAP+HGPIN in the first biopsy, prostate cancer was detected in 3 patients in the second biopsy and in 1 patient in the third biopsy.

Conclusions

The diagnosis of ASAP is a strong risk factor for prostate cancer. A repeat biopsy should be performed for the entire prostate subsequent to the diagnosis of ASAP. In patients with HGPIN according to the biopsy result, the clinical decision should be based on other parameters, such as PSA values and rectal examination, and a repeat biopsy should be avoided if the initial biopsy was performed with multiple sampling.

A comparative performance analysis of total prostate-specific antigen, percentage free prostate-specific antigen, prostate-specific antigen velocity and urinary prostate cancer gene 3 in the first, second and third repeat prostate biopsy

Study Type - Diagnosis (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Risk factor assessment in the repeat biopsy setting is affected by a decreasing diagnostic accuracy of each single risk factor (e.g. DRE, tPSA, %fPSA, complexed PSA, PSA density or PSAV] with increasing number of prostate biopsy sessions. PCA3 shows impressive diagnostic performance in the initial and early repeat biopsy settings. In a head-to-head comparison we demonstrate the concept that the number of previous repeat biopsy session strongly influences performance characteristics of biopsy risk factors, including PCA3. While the novel diagnostic marker would have avoided a considerable number of unnecessary biopsies in the first repeat biopsy scenario, its effects dissipated at second and ≥ third repeat biopsies.

OBJECTIVE

To compare the performance characteristics of prostate cancer risk factors such as total prostate-specific antigen (tPSA), percentage free PSA (%fPSA), PSA velocity (PSAV) and urinary prostate cancer gene 3 (PCA3) at first, second and ≥ third repeat biopsy session.

PATIENTS AND METHODS

Patients (n= 127) aged ≤70 years, with suspicious digital rectal examination (DRE) and/or persistently elevated age-specific total PSA levels (2.5-6.5 ng/mL) and/or suspicious prior histology (atypical small acinar proliferations [ASAPs]≥ two cores affected by high-grade prostatic intra-epithelial neoplasia [HGPIN]) undergoing either a first, second, or ≥ third repeat biopsy were investigated using a 12- or 24-core biopsy scheme. PSAV (≥ three values collected over ≥12 months) was calculated using the log-slope method. PCA3 scores were assessed using the Progensa assay®. After stratification according to the number of previous biopsies (first, second and ≥ third), calculation of specificity, positive and negative predictive values (PPV, NPV) and the proportion of avoided unnecessary repeat biopsies (PAB) compared with tPSA at fixed sensitivity thresholds (75, 85 and 95%) were performed. Finally, accuracy estimates (area under the curve [AUC]) were quantified for each repeat biopsy scenario.

RESULTS

At repeat biopsy, overall prostate cancer (PCa) detection was 34.6%. At first repeat biopsy, PCA3 predicted PCa best (AUC = 0.80) and would have avoided 72.2% of repeat biopsies (75% sensitivity) compared with tPSA. At second repeat biopsy, %fPSA demonstrated the highest accuracy (AUC = 0.82) and would have avoided 66.7% of repeat biopsies (75% sensitivity) compared with tPSA. At ≥ third repeat biopsy, again %fPSA demonstrated the highest accuracy (AUC = 0.70) and would have avoided 45.0% of repeat biopsies (75% sensitivity) compared with tPSA. The main limitation of our study resides in its small sample size.

CONCLUSIONS

The findings of the present study promote the concept that the number of previous repeat biopsy sessions strongly influences the performance characteristics of biopsy risk factors. Total PSA was no significant risk factor in the entire analysis. By contrast, %fPSA performed best at second and ≥ third repeat biopsy. PSAV's diagnostic potential was reserved to patients at second and ≥ third repeat biopsy. Finally, PCA3 demonstrated the highest diagnostic accuracy and potential to reduce unnecessary biopsies at first repeat biopsy. However, this advantage dissipated at second and ≥ third repeat biopsy.

Construction of tissue micro array from prostate needle biopsies using the vertical clustering re-arrangement technique

BACKGROUND

Tissue microarray (TMA) allows for simultaneous rapid expression analysis of multiple molecular targets in many tissue specimens. TMA's are specifically in demand for the screening for diagnostic and prognostic markers in prostate cancer (PC). Consequently, TMAs from prostate needle biopsy (PNB) material taken at diagnosis before any treatment commenced are in demand. However, since PNB contain only limited amount of tumor arranged within a very thin tissue core, TMA construction from PNB is problematic.

METHODS

Archival PNB from 30 PC patients with variable Gleason scores (6-10) and % of cores involvement (30-90%) were used. Following selection of representative cores, the paraffin blocks were melted. Each core was sectioned into equal parts of 3-4 mm in length. For each case, a group of fragments was then re-embedded in a vertical orientation. Using Manual TMA Apparatus, 2 mm cores from each of the vertically rearranged fragments were harvested. Sections (4 µm) were stained with H&E and with high-molecular weight cytokeratin (HMWCK), PIN-cocktail (p63 + p504S), and PSA immunohistochemical stains.

RESULTS

A TMA from PNB with a capacity of 80 serial 4 µm sections was constructed. In all cases, identical tumor and neighboring tissue morphology (atrophic changes and high-grade prostatic intra-epithelial neoplasia) with no loss of tissue was evident.

CONCLUSIONS

The vertical clustering re-arrangement (VCR) technique is suitable for large scale construction of TMA blocks from PNB maintaining the morphological and immunohistochemical characteristics of the original samples. This method is promising both in terms of archival tissue preservation and biomarkers research.

Molecular diagnostics in urologic malignancies: a work in progress

CONTEXT

Molecular diagnostic applications are now an integral part of the management algorithms of several solid tumors, such as breast, colon, and lung. In stark contrast, the current clinical management of urologic malignancies is lagging behind. Clinically robust molecular tests that can identify patients who are more likely to respond to a given targeted agent or even those in need of a more aggressive treatment based on well-validated molecular prognosticators are still lacking. Several promising biomarkers for detection, prognosis, and targeted therapeutics are being evaluated.

OBJECTIVE

To discuss candidate biomarkers that may soon make the transition to clinical assay for patients in urologic oncology.

DATA SOURCES

Selected original articles published in the PubMed service of the US National Library of Medicine.

CONCLUSIONS

Recent understanding of the complex molecular alterations involved in the development and progression of urologic malignancies is yielding novel diagnostic and prognostic molecular tools and opening the doors for experimental targeted therapies in these prevalent, frequently lethal solid tumors.

Pathology in prostate research: optimizing the pathological data

Pathology remains the gold standard for the diagnosis and local staging and grading of prostate cancer. However, as in any discipline, there are variations in national standards and protocols leading to possible significant intra-observer variations. This can significantly impact on the data supplied to clinical trials. Diagnostic and grading criteria. Error rates in the diagnosis of prostate cancer have improved but the possibility that diagnostic error may be discovered has to be addressed in any research series. Major changes in Gleason grading have occurred in the past 40 years and this may lead to suboptimal application of grades in research cohorts, falsely raising the prognostic power of new biomarkers. Tumor measurements and staging criteria. Further information that may provide additional prognostic information include various measures of tumor extent and peri-neural invasion in biopsy specimens. Standardization of measures of tumor extent is necessary to give more useful assessments of prognosis. In radical prostatectomy specimens there are a number of other staging measurements which might be applied, including tumor volume, margin status, extra-capsular extension and nodal positivity though many of these variables are interdependent. Conclusion. Appropriate utilization of such pathological material will produce improved cohorts in which it will be possible to test new biomarkers with increased rigor.

Prognostic significance of focal neuroendocrine differentiation in prostate cancer: cases with autopsy-verified cause of death

AIMS

This study was designed to evaluate the prognostic significance of focal chromogranin A (cgA) expression in prostate cancer in a series of cases with autopsy-verified cause of death.

METHODS AND RESULTS

Seventy seven autopsy-verified cases of prostate cancer were identified, 41 cases with metastatic disease and 36 with nonmetastatic disease at autopsy. Immunohistochemical analysis for cgA was performed in 40 cases on the archived diagnostic biopsies taken during the patients' lifetime. After exclusion of a single case of carcinoid tumor, 14 of the 18 (78%) metastatic and none of the 21 (0%) nonmetastatic tumors showed focal neuroendocrine differentiation (NED). The Gleason score and focal cgA expression further increased the accuracy of the prediction of the outcome, as all the cases with focal NED associated with high Gleason score had metastatic disease in contrast to cases without cgA-expression and low Gleason score, all of which were non-metastatic.

CONCLUSIONS

Focal NED seems to be a powerful negative prognostic parameter in prostate adenocarcinomas. The outcome of the disease in prostate cancer can be accurately predicted based on focal NED of the tumor cells either alone or in combination with Gleason score.

Critical assessment of preoperative urinary prostate cancer antigen 3 on the accuracy of prostate cancer staging

BACKGROUND

Knowledge about the staging significance of the prostate cancer antigen 3 (PCA3) score to better identify pathologic features after radical prostatectomy (RP) is limited and controversial.

OBJECTIVE

Our aim was to study the clinical staging significance of PCA3 to identify pathologic favorable and/or unfavorable features in the RP specimen.

DESIGN, SETTING, AND PARTICIPANTS

Complete retrospective clinical and pathologic data of consecutive men who had undergone RP from three tertiary referral centers including preoperative PCA3 scores (n=305) and computer-assisted planimetrically measured tumor volume data (n=160) were available.

INTERVENTION

All patients were treated with RP.

MEASUREMENTS

PCA3 scores were assessed using the PROGENSA assay (Gen-Probe, San Diego, CA, USA). Beyond standard risk factors (age, digital rectal examination, prostate-specific antigen, prostate volume, biopsy Gleason score, percentage of positive cores), five different PCA3 codings were used in logistic regression models to identify five distinct pathologic end points: (1) low-volume disease (<0.5 ml), (2) insignificant prostate cancer (PCa) according to the Epstein criteria, (3) extracapsular extension (ECE), (4) seminal vesicle invasion (SVI), and (5) aggressive disease defined as Gleason sum ≥7. Accuracy estimates of each end point were quantified using the area under the curve (AUC) of the receiver operator characteristic analysis in models with and without PCA3.

RESULTS AND LIMITATIONS

PCA3 scores were significantly lower in low-volume disease and insignificant PCa (p ≤ 0.001). AUC of multivariable low-volume disease (+2.4 to +5.5%) and insignificant PCa models (+3 to +3.9%) increased when PCA3 was added to standard clinical risk factors. In contradistinction, regardless of its coding, PCA3 scores were not significantly elevated in pathologically confirmed ECE (p=0.4) or SVI (p=0.5), respectively. Higher PCA3 scores were associated with aggressive disease (p<0.001). Importantly, the addition of PCA3 to multivariable intermediate- and high-grade models did not improve prediction. Despite reporting the largest pathologic PCA3 study, the main limitation resides in its small sample size.

CONCLUSIONS

PCA3 was confirmed as a valuable predictor of pathologically confirmed low-volume disease and insignificant PCa. Further exploration of its role as an additional marker to select patients for active surveillance may be warranted. In contradistinction, assessment of pathologically advanced or aggressive PCa is not improved using PCA3.

Beta-tubulin III expression in prostate cancer

OBJECTIVE

Beta-tubulin isotype III is a microtubule component associated with resistance to chemotherapy and poor outcome in various cancers. This study aimed to investigate its expression in prostate cancer and its role as a prognostic factor in this setting.

MATERIAL AND METHODS

A tissue microarray was constructed of 289 prostate cancers from radical prostatectomy specimens with a median follow-up of 48.9 months. Slides were immunostained for β-tubulin III. The intensity and extent of immunoreactivity and their product [immunoreactivity product (IRP)] were evaluated.

RESULTS

Tubulin III was expressed in the cytoplasm of prostate cancer cells but not in benign glands. Only 11.6% of cancers were positive for tubulin III. Among low-grade (Gleason score 5-6) and high-grade (Gleason score 7-10) cancers, 6.0% and 16.6% were positive, respectively (p = 0.006). β-Tubulin III expression was more often seen in high-stage disease and more often in metastases (62.5%) than in primary lesions (11.6%) (p < 0.001). The intensity, extent and IRP of tubulin III all predicted biochemical recurrence in univariate Cox analysis (p = 0.02, p = 0.048 and p = 0.012, respectively). IRP was an independent predictor of prognosis when adjusted for serum prostate-specific antigen in a multivariate Cox analysis (p = 0.005), but not when the Gleason score was added to the model (p = 0.17).

CONCLUSION

β-Tubulin III predicts biochemical recurrence after radical prostatectomy in a subset of patients. Its practical utility is limited by the low number of cases positive for this biomarker.

Theranostic and prognostic biomarkers: genomic applications in urological malignancies

Compared to other solid tumours such as breast, colon, and lung, the current clinical management of urological malignancies is lagging behind in terms of utilisation of clinically robust molecular tests that can identify patients that are more likely to respond to a given targeted agent, or even those in need of a more aggressive treatment approach based on well-validated molecular prognosticators. Several promising biomarkers for detection, prognosis, and targeted therapeutics are now under evaluation. The following review discusses some of the candidate biomarkers that may soon make their transition into clinically applicable assays in urological oncology patients.

External validation of urinary PCA3-based nomograms to individually predict prostate biopsy outcome

BACKGROUND

Prior to safely adopting risk stratification tools, their performance must be tested in an external patient cohort.

OBJECTIVE

To assess accuracy and generalizability of previously reported, internally validated, prebiopsy prostate cancer antigen 3 (PCA3) gene-based nomograms when applied to a large, external, European cohort of men at risk of prostate cancer (PCa).

DESIGN, SETTING, AND PARTICIPANTS

Biopsy data, including urinary PCA3 score, were available for 621 men at risk of PCa who were participating in a European multi-institutional study.

INTERVENTION

All patients underwent a ≥10-core prostate biopsy. Biopsy indication was based on suspicious digital rectal examination, persistently elevated prostate-specific antigen level (2.5-10 ng/ml) and/or suspicious histology (atypical small acinar proliferation of the prostate, >/= two cores affected by high-grade prostatic intraepithelial neoplasia in first set of biopsies).

MEASUREMENTS

PCA3 scores were assessed using the Progensa assay (Gen-Probe Inc, San Diego, CA, USA). According to the previously reported nomograms, different PCA3 score codings were used. The probability of a positive biopsy was calculated using previously published logistic regression coefficients. Predicted outcomes were compared to the actual biopsy results. Accuracy was calculated using the area under the curve as a measure of discrimination; calibration was explored graphically.

RESULTS AND LIMITATIONS

Biopsy-confirmed PCa was detected in 255 (41.1%) men. Median PCA3 score of biopsy-negative versus biopsy-positive men was 20 versus 48 in the total cohort, 17 versus 47 at initial biopsy, and 37 versus 53 at repeat biopsy (all p≤0.002). External validation of all four previously reported PCA3-based nomograms demonstrated equally high accuracy (0.73-0.75) and excellent calibration. The main limitations of the study reside in its early detection setting, referral scenario, and participation of only tertiary-care centers.

CONCLUSIONS

In accordance with the original publication, previously developed PCA3-based nomograms achieved high accuracy and sufficient calibration. These novel nomograms represent robust tools and are thus generalizable to European men at risk of harboring PCa. Consequently, in presence of a PCA3 score, these nomograms may be safely used to assist clinicians when prostate biopsy is contemplated.