Digital rectal examination in primary care is important for early detection of prostate cancer: a retrospective cohort analysis study

Value of digital rectal examination in patients with suspected prostate cancer: a prospective cohort analysis study

Background

Digital rectal examination (DRE) is a straightforward, cost-effective, practical, and time-honored physical examination method that plays a valuable role in the detection of prostate cancer (PCa). Nevertheless, with the advent of the prostate-specific antigen (PSA) era, the necessity of performing DRE has become a subject of debate. Our aim was to investigate the diagnostic efficacy and adjunctive role of DRE in a population (Prostate Imaging Reporting and Data System (PI-RADS), PI-RADS ≥3 or PSA ≥4 ng/mL) suspected of PCa.

Methods

Five hundred and ninety-seven patients with suspected PCa requiring referral for biopsy were prospectively enrolled consecutively from February 2020 to May 2021. All patients received DRE and corresponding clinical diagnosis by a urologist before biopsy. According to the collected clinical and pathological information, the diagnostic performance of DRE in different PSA stratifications, and its association with tumor location and Gleason score (GS) were statistically analyzed.

Results

Among patients with suspected cancer, the diagnostic accuracy of DRE was 63.45%. Compared with central zone or transition zone tumors, the recall rate of peripheral zone PCa with DRE-positive results was higher (65.50% vs. 34.55%). DRE-positive results were significantly correlated with GS ≥7 PCa (P<0.001), and the average GS of DRE-positive PCa patients was significantly higher than that of DRE-negative (7.92 vs. 7.11, P<0.001).

Conclusions

DRE may help physicians further judge the necessity of biopsy in patients with elevated PSA, and preliminarily estimate the location and invasiveness of the tumor. However, it is still necessary to explore the value of DRE in a normal PSA population.

Accurate prostate cancer detection based on enrichment and characterization of prostate cancer specific circulating tumor cells

BACKGROUND

The low specificity of serum PSA resulting in the inability to effectively differentiate prostate cancer from benign prostate conditions is a persistent clinical challenge. The low sensitivity of serum PSA results in false negatives and can miss high-grade prostate cancers. We describe a non-invasive test for detection of prostate cancer based on functional enrichment of prostate adenocarcinoma associated circulating tumor cells (PrAD-CTCs) from blood samples followed by their identification by immunostaining for pan-cytokeratins (PanCK), prostate specific membrane antigen (PSMA), alpha methyl-acyl coenzyme-A racemase (AMACR), epithelial cell adhesion molecule (EpCAM), and common leucocyte antigen (CD45).

METHODS

Analytical validation studies were performed to establish the performance characteristics of the test using VCaP prostate cancer cells spiked into healthy donor blood (HDB). The clinical performance characteristics of the test were evaluated in a case-control study with 160 known prostate cancer cases and 800 healthy males, followed by a prospective clinical study of 210 suspected cases of prostate cancer.

RESULTS

Analytical validation established analyte stability as well as acceptable performance characteristics. The test showed 100% specificity and 100% sensitivity to differentiate prostate cancer cases from healthy individuals in the case control study and 91.2% sensitivity and 100% specificity to differentiate prostate cancers from benign prostate conditions in the prospective clinical study.

CONCLUSIONS

The test accurately detects PrAD-CTCs with high sensitivity and specificity irrespective of stage, serum PSA or Gleason score, which translates into low risks of false negatives or overdiagnosis. The high accuracy of the test could offer advantages over PSA based prostate cancer detection.

Design of a printed electrochemical strip towards miRNA-21 detection in urine samples: optimization of the experimental procedures for real sample application

MicroRNAs (miRNAs) are clinical biomarkers for various human diseases, including cancer. They have been found in liquid biopsy samples, including various bodily fluids. They often play an important role in the early diagnosis and prognosis of cancer, and the development of simple and effective analytical methods would be of pivotal importance for the entire community. The determination of these targets may be affected by the different physicochemical parameters of the specimen of interest. In this work, an electrochemical detection platform for miRNA based on a screen-printed gold electrode was developed. In the present study, miRNA-21 was selected as a model sequence, due to its role in prostate, breast, colon, pancreatic, and liver cancers. A DNA sequence modified with methylene blue (MB) was covalently bound to the electrochemical strip and used to detect the selected target miRNA-21. After optimization of selected parameters in standard solutions, including the study of the effect of pH, the presence of interferent species, and NaCl salt concentration in the background, the application of square-wave voltammetry (SWV) technique allowed the detection of miRNA-21 down to a limit in the order of 2 nM. The developed device was then applied to several urine samples. In this case too, the device showed high selectivity in the presence of the complex matrix, satisfactory repeatability, and a limit of detection in the order of magnitude of nM, similarly as what observed in standard solutions.

Diagnostic value of the abnormal digital rectal examination in the modern MRI-based prostate cancer diagnostic pathway

Objective

Currently the National Institute for Health and Care Excellence (NICE) recommends an abnormal digital rectal examination (DRE) as a standalone referral criterion for suspected prostate cancer. Unlike referrals for a raised prostate-specific antigen (PSA) which are triaged directly to magnetic resonance imaging (MRI), an abnormal DRE requires re-examination in a secondary clinic first. Here, we investigated the ongoing value of the abnormal DRE as a referral criterion.

Methods

This study is a retrospective review of patients referred to secondary care for suspected prostate cancer based on an abnormal DRE over a 15-month period at a single UK hospital (n = 158). Age, PSA, primary and repeat DRE findings and eventual diagnosis were collated.

Results

A concurrent raised PSA was present in 65/158 (41%). Concordance between primary and secondary care DRE was only 72/158 (46%). The overall and significant cancer detection rate was 26/158 (16%) and 22/158 (14%), respectively. Among men with a concurrent raised PSA, 19/65 (29%) had significant cancer found, whereas with an abnormal primary care DRE and normal PSA (n = 93), only 3/93 (3%) had a significant cancer. Mandating a PSA before referral for an abnormal DRE would have redirected 65/158 (41%) of men to MRI first, negating the need for a repeat DRE (p < 0.0001). This finding was recapitulated in a second prospective validation cohort (n = 30) with 9/30 (30%) redirected to MRI first.

Conclusions

This is one of the first studies to investigate the value of the DRE in contemporary practice. We propose that PSA is used to triage men with an abnormal DRE to MRI without needing a repeat DRE. If the PSA is normal, the diagnostic yield is low but may still warrant a repeat DRE to assess the need for further investigations. Additional multicentre studies are required to further validate our findings.

Level of evidence

4.

Emerging role of exosomes as biomarkers in cancer treatment and diagnosis

Cancer is a leading cause of death worldwide and cancer incidence and mortality are rapidly growing. These massive amounts of cancer patients require rapid diagnosis and efficient treatment strategies. However, the currently utilized methods are invasive and cost-effective. Recently, the effective roles of exosomes as promising diagnostic, prognostic, and predictive biomarkers have been revealed. Exosomes are membrane-bound extracellular vesicles containing RNAs, DNAs, and proteins, and are present in a wide array of body fluids. Exosomal cargos have shown the potential to detect various types of cancers at early stages with high sensitivity and specificity. They can also delivery therapeutic agents efficiently. In this article, an overview of recent advances in the research of exosomal biomarkers and their applications in cancer diagnosis and treatment has been provided. Furthermore, the advantages and challenges of exosomes as liquid biopsy targets are discussed and the clinical implications of using exosomal miRNAs have been revealed.

How to Improve TRUS-Guided Target Biopsy following Prostate MRI

TRUS is a basic imaging modality when radiologists or urologists perform cognitive fusion or image fusion biopsy. This modality plays the role of the background images to add to an operator's cognitive function or MRI images. Operators need to know how to make TRUS protocols for lesion detection or targeting. Tumor location, size, and shape on TRUS are different from those on MRI because the scan axis is different. TRUS findings of peripheral or transition tumors are not well known to radiologists and urologists. Moreover, it remains unclear if systematic biopsy is necessary after a tumor is targeted. The purpose of this review is to introduce new TRUS protocols, new imaging features, new biopsy techniques, and to assess the necessity of systematic biopsy for improving biopsy outcomes.

Miniaturized optical fiber probe for prostate cancer screening

Tissue elasticity is universally recognized as a diagnostic and prognostic biomarker for prostate cancer. As the first diagnostic test, the digital rectal examination is used since malignancy changes the prostate morphology and affects its mechanical properties. Currently, this examination is performed manually by the physician, with an unsatisfactory positive predictive value of 42%. A more objective and spatially selective technique is expected to provide a better prediction degree and understanding of the disease. To this aim, here we propose a miniaturized probe, based on optical fiber sensor technology, for mechanical characterization of the prostate with sub-millimeter resolution. Specifically, the optical system incorporates a customized Fiber Bragg Grating, judiciously integrated in a metallic cannula and moved by a robotic arm. The probe enables the local measurement of the force upon tissue indentation with a resolution of 0.97 mN. The system has been developed in such a way to be potentially used directly in vivo. Measurements performed on phantom tissues mimicking different stages of the prostatic carcinoma demonstrated the capability of our device to distinguish healthy from diseased zones of the prostate. The study on phantoms has been complemented with preliminary ex vivo experiments on real organs obtained from radical surgeries. Our findings lay the foundation for the development of advanced optical probes that, when integrated inside biopsy needle, are able to perform in vivo direct mechanical measurements with high sensitivity and spatial resolution, opening to new scenarios for early diagnosis and enhanced diagnostic accuracy of prostate cancer.

The Digital Divide: A Retrospective Survey of Digital Rectal Examinations during the Workup of Rectal Cancers

Background: Digital rectal examination (DRE) is considered an important part of the physical examination. However, it is unclear how many patients have a DRE performed at the primary care level in the work-up of rectal cancer, and if the absence of a DRE causes a delay to consultation with a specialist. Methods: A retrospective patient questionnaire was sent to 1000 consecutive patients with stage II or stage III rectal cancer. The questionnaire asked patients to recall if they had a DRE performed by their general practitioner (GP) when they first presented with symptoms or a positive FIT test. Demographic data, staging data, and time to consultation with a specialist were also collected. Results: A thousand surveys were mailed out, and a total of 262 patients responded. Of the respondents, 46.2% did not recall undergoing a digital rectal examination by their primary care provider. Women were less likely to undergo a DRE than men (28.6% vs. 44.3%, p = 0.019). While there was a trend towards longer times to specialist consultation in patients who did not undergo a DRE (27.0 vs. 12.2 weeks), this was not statistically significant (p = 0.121). Conclusion: A significant proportion of patients who are FIT positive or have symptomatic rectal bleeding do not recall having a DRE by their primary care provider. Barriers may include lack of comfort with performing DRE or lack of time. Clearer guidelines and more support for GP’s may increase uptake of DRE.

Does a screening digital rectal exam provide actionable clinical utility in patients with an elevated PSA and positive MRI?

Objective

To define the value of a digital rectal exam (DRE) in the prostate‐magnetic resonance imaging (MRI) era. Prostate MRI is increasingly used in men with elevated prostate‐specific antigen (PSA) prior to biopsy.

Methods

A retrospective study was performed in men with elevated PSA undergoing MRI followed by MRI fusion with systematic biopsy and men with elevated PSA/active surveillance with negative MRI followed by biopsy. Baseline clinicopathologic characteristics and DRE findings were collected. We examined performance of a positive DRE on sensitivity and specificity of diagnosing clinically significant prostate cancer (CSPC).

Results

A total of 339 patients had elevated PSA and positive MRI followed by MRI fusion guided with systematic biopsy. Pre‐biopsy DRE was documented in 286/339 patients, who were included in further analysis. About 81.6% positive, 78.7% questionable, and 55.8% negative DRE patients had CSPC. Positive DRE had 21.8% sensitivity and 91.3% specificity for CSPC. Positive or questionable DRE had 42.1% sensitivity and 81.5% specificity. Among 148 men with non‐CSPC (GG1)‐targeted biopsy, 28 had systematic biopsy with CSPC. About 5/28 had positive DRE and 8/28 had positive or questionable DRE. Twenty‐seven patients were included who had elevated PSA/on active surveillance with negative MRI and biopsy done within 2 years. About 77.8% had negative, 7.4% had questionable, and 14.8% men had positive DRE. About 7.4% had CSPC and all had a negative DRE.

Conclusions

Our study provides limited evidence for the value of a DRE. However, it does show occasional benefit in detecting GG2 or higher disease and given the lack of cost and side effects, should still be considered.

Clinical diagnosis of prostate cancer using digital rectal examination and prostate-specific antigen tests: a systematic review and meta-analysis of sensitivity and specificity

Background

Being diagnosed with cancer, irrespective of type initiates a serious psychological concern. The increasing rate of detection of indolent prostate cancers is a source of worry to public health. Digital rectal examination and prostate-specific antigen tests are the commonly used prostate cancer screening tests. Understanding the diagnostic accuracies of these tests may provide clearer pictures of their characteristics and values in prostate cancer diagnosis. This review compared the sensitivities and specificities of digital rectal examination and prostate-specific antigen test in detection of clinically important prostate cancers using studies from wider population.

Main body

We conducted literature search in PubMed, Medline, Science Direct, Wiley Online, CINAHL, Scopus, AJOL and Google Scholar, using key words and Boolean operators. Studies comparing the sensitivity and specificity of digital rectal examination and prostate-specific antigen tests in men 40 years and above, using biopsy as reference standard were retrieved. Data were extracted and analysed using Review manager (RevMan 5.3) statistical software. The overall quality of the studies was good, and heterogeneity was observed across the studies. The result comparatively shows that prostate-specific antigen test has higher sensitivity (P < 0.00001, RR 0.74, CI 0.67–0.83) and specificity (P < 0.00001, RR 1.81, CI 1.54–2.12) in the detection of prostate cancers than digital rectal examination.

Conclusion

Prostate-specific antigen test has higher sensitivity and specificity in detecting prostate cancers from men of multiple ethnic origins. However, combination of prostate-specific antigen test and standardized digital rectal examination procedure, along with patients history, may improve the accuracy and minimize over-diagnoses of indolent prostate cancers.

Exploring the Process of Cancer Care for Patients With Pre-Existing Mobility Disability

PURPOSE

Approximately 13% of the US population report mobility disability. People with mobility disability experience healthcare disparities, including lower rates of cancer screening and substandard cancer care compared with nondisabled people. We explored clinicians' reports of aspects of diagnosing and treating three common cancer types among persons with pre-existing mobility disability.

METHODS

We used standard diagnosis codes and natural language processing to screen electronic health records (EHR) in the Research Patient Data Repository for patients with pre-existing chronic mobility impairment who were newly diagnosed with one of three common cancers (colorectal, prostate, and non-Hodgkin lymphoma) between 2005 and 2017. We eliminated numerous cases whose EHRs lacked essential information. We reviewed EHRs of 27 cases, using conventional content analysis to identify themes concerning their cancer diagnoses and treatments.

RESULTS

Clinicians' notations coalesced around four major themes: (1) patients' health risks raise concerns about diagnostic processes; (2) cancer signs or symptoms can be erroneously attributed to the patient's underlying disabling condition, delaying diagnosis; (3) disability complicates cancer treatment decisions; and (4) problems with equipment accessibility and disability accommodations impede cancer diagnoses.

DISCUSSION

Clinicians view patients with pre-existing mobility disability as often clinically complex, presenting challenges for diagnosing and treating their cancer. Nonetheless, these patients may experience substandard care because of disability-related problems. Given the growing population of people with mobility disability, further efforts to improve care quality and timeliness of diagnosis are warranted.

Assessment of the value of the different variants of abnormal digital rectal examination finding in predicting carcinoma of the prostate: a preliminary report of a two-center study

Background

Digital rectal examination is a veritable tool for the clinical diagnosis and screening for carcinoma of the prostate. This study aims to assess the value of the different variables which constitute abnormal digital rectal examination (DRE) findings.

Results

Following ethical approval, one hundred and thirty-one men met the inclusion criteria and were enrolled in the study. The peak incidence of abnormal DRE finding was in the 8th decade of life, while the PPV was 66.5%. Of the total, 44 (33.5%) were nodular hyperplasia, 12 (9.2%) were prostate intra-epithelia neoplasia, while 75 (57.3%) were adenocarcinoma. With a positive predictive value (PPV) of 73.3%, a hard nodular feel was the only abnormal DRE finding that independently and significantly predicted the risk of prostatic adenocarcinoma. A suspicious nodule and obliterated median groove had PPV of 23.1% and lobar asymmetry, 0%. There was a statistically significant correlation (P = 0.005) between DRE findings and histology, between PSA and histology (P = 0.000) and between the size of the prostate and PSA value (P = 0.021). The mean size of the prostate was 101.2 g, standard deviation 92.11783, maximum 648 g and minimum 13.6 g.

Conclusion

Most of the variants of abnormal DRE findings do not sufficiently predict the risk of adenocarcinoma on their own. They need to be in combination with other DRE findings or a raised PSA to significantly predict adenocarcinoma.

Clinical proteomics for prostate cancer: understanding prostate cancer pathology and protein biomarkers for improved disease management

Following the introduction of routine Prostate Specific Antigen (PSA) screening in the early 1990's, Prostate Cancer (PCa) is often detected at an early stage. There are also a growing number of treatment options available and so the associated mortality rate is generally low. However, PCa is an extremely complex and heterogenous disease and many patients suffer disease recurrence following initial therapy. Disease recurrence commonly results in metastasis and metastatic PCa has an average survival rate of just 3-5 years. A significant problem in the clinical management of PCa is being able to differentiate between patients who will respond to standard therapies and those who may benefit from more aggressive intervention at an earlier stage. It is also acknowledged that for many men the disease is not life threatenting. Hence, there is a growing desire to identify patients who can be spared the significant side effects associated with PCa treatment until such time (if ever) their disease progresses to the point where treatment is required. To these important clinical needs, current biomarkers and clinical methods for patient stratification and personlised treatment are insufficient. This review provides a comprehensive overview of the complexities of PCa pathology and disease management. In this context it is possible to review current biomarkers and proteomic technologies that will support development of biomarker-driven decision tools to meet current important clinical needs. With such an in-depth understanding of disease pathology, the development of novel clinical biomarkers can proceed in an efficient and effective manner, such that they have a better chance of improving patient outcomes.

The awareness of women on prostate cancer: a mixed-methods systematic review protocol

BACKGROUND

Prostate cancer accounts for about 10% of cancers affecting and claiming the lives of men. Studies have reported that women are better than men in recognition of the early manifestations of various cancers. Besides, women have been recognized to show a profound interest in their partners' health and hence, make observations that men do not know. Several studies have reported on the knowledge gaps of prostate cancer among patients and the general population. It is vital to comprehensively review the available evidence and identify research gaps in our current understanding of knowledge of women on prostate cancer.

METHODS

A search of bibliographic databases, MEDLINE (EBSCOhost), CINAHL (EBSCOhost), PsycINFO (EBSCOhost), Web of Science, and EMBASE (Ovid) will be undertaken from January 1999 to December 2019. The search will be limited to studies published in the English language. Duplication of studies will be removed using the EndNote citation manager. After deduplication, citations will be screened independently by two authors according to prespecified criteria. Data extraction and quality assessment of the selected studies will be done independently by two authors. Meta-analytic methods will be used where appropriate. The convergent segregated method of synthesis will be adopted in this review.

ETHICS AND DISSEMINATION

Primary data collection will not be involved in this study, hence formal ethical clearance will not be needed. The results of the study will be presented through a peer-reviewed journal and conference presentation.

PATIENT AND PUBLIC INVOLVEMENT

Patients or the public will not be engaged in the conduct of this study.

TRIAL REGISTRATION

Open Science Framework (OSF) registration DOI: https://doi.org/10.17605/OSF.IO/EYHF2.

Prostate cancer early diagnosis: circulating microRNA pairs potentially beyond single microRNAs upon 1231 serum samples

The accuracy of prostate-specific antigen or clinical examination in prostate cancer (PCa) screening is in question, and circulating microRNAs (miRNAs) can be alternatives to PCa diagnosis. However, recent circulating miRNA biomarkers either are identified upon small sample sizes or cannot have robust diagnostic performance in every aspect of performance indicators. These may decrease applicability of potential biomarkers for the early detection of PCa. We reviewed recent studies on blood-derived miRNAs for prostate cancer diagnosis and carried out a large case study to understand whether circulating miRNA pairs, rather than single circulating miRNAs, could contribute to a more robust diagnostic model to significantly improve PCa diagnosis. We used 1231 high-throughput miRNA-profiled serum samples from two cohorts to design and verify a model based on class separability miRNA pairs (cs-miRPs). The pairwise model was composed of five circulating miRNAs coupled to miR-5100 and miR-1290 (i.e. five miRNA pairs, 5-cs-miRPs), reaching approximately 99% diagnostic performance in almost all indicators (sensitivity = 98.96%, specificity = 100%, accuracy = 99.17%, PPV = 100%, NPV = 96.15%) shown by a test set (n = 484: PCa = 384, negative prostate biopsies = 100). The nearly 99% diagnostic performance was also verified by an additional validation set (n = 140: PCa = 40, healthy controls = 100). Overall, the 5-cs-miRP model had 1 false positive and 7 false negatives among the 1231 serum samples and was superior to a recent 2-miRNA model (so far the best for PCa diagnosis) with 18 false positives and 80 false negatives. The present large case study demonstrated that circulating miRNA pairs could potentially bring more benefits to PCa early diagnosis for clinical practice.

Intrinsic Disorder of the BAF Complex: Roles in Chromatin Remodeling and Disease Development

The two-meter-long DNA is compressed into chromatin in the nucleus of every cell, which serves as a significant barrier to transcription. Therefore, for processes such as replication and transcription to occur, the highly compacted chromatin must be relaxed, and the processes required for chromatin reorganization for the aim of replication or transcription are controlled by ATP-dependent nucleosome remodelers. One of the most highly studied remodelers of this kind is the BRG1- or BRM-associated factor complex (BAF complex, also known as SWItch/sucrose non-fermentable (SWI/SNF) complex), which is crucial for the regulation of gene expression and differentiation in eukaryotes. Chromatin remodeling complex BAF is characterized by a highly polymorphic structure, containing from four to 17 subunits encoded by 29 genes. The aim of this paper is to provide an overview of the role of BAF complex in chromatin remodeling and also to use literature mining and a set of computational and bioinformatics tools to analyze structural properties, intrinsic disorder predisposition, and functionalities of its subunits, along with the description of the relations of different BAF complex subunits to the pathogenesis of various human diseases.

County-Level Unemployment Rates and Service Intensity in Primary Care Physician Offices for Medicare Patients

The macroeconomic environment has been shown to affect health-care service utilization. We examined the relationship between unemployment rate and service intensity among a nationally representative sample of primary care office visits from Medicare patients by merging data from the 2006-2012 National Ambulatory Medical Care Survey with unemployment data from the Bureau of Labor Statistics. Multispecialty practices demonstrated increases in the number of electrocardiogram tests prescribed and the number of return appointments scheduled. In contrast, single-specialty practices did not respond on those margins and instead increased the likelihood of administering diagnostic and screening examinations. We found no significant relationship between unemployment rates and the number of laboratory and imaging services, magnetic resonance imaging use, referrals, or medication prescribing. These results were robust to controlling for extensive visit characteristics and county-, year-, and month-fixed effects. Our results suggest that physicians responded to the Great Recession by changing their practice behavior.

Is it possible to automatically assess pretreatment digital rectal examination documentation using natural language processing? A single-centre retrospective study

OBJECTIVES

To develop and test a method for automatic assessment of a quality metric, provider-documented pretreatment digital rectal examination (DRE), using the outputs of a natural language processing (NLP) framework.

SETTING

An electronic health records (EHR)-based prostate cancer data warehouse was used to identify patients and associated clinical notes from 1 January 2005 to 31 December 2017. Using a previously developed natural language processing pipeline, we classified DRE assessment as documented (currently or historically performed), deferred (or suggested as a future examination) and refused.

PRIMARY AND SECONDARY OUTCOME MEASURES

We investigated the quality metric performance, documentation 6 months before treatment and identified patient and clinical factors associated with metric performance.

RESULTS

The cohort included 7215 patients with prostate cancer and 426 227 unique clinical notes associated with pretreatment encounters. DREs of 5958 (82.6%) patients were documented and 1257 (17.4%) of patients did not have a DRE documented in the EHR. A total of 3742 (51.9%) patient DREs were documented within 6 months prior to treatment, meeting the quality metric. Patients with private insurance had a higher rate of DRE 6 months prior to starting treatment as compared with Medicaid-based or Medicare-based payors (77.3%vs69.5%, p=0.001). Patients undergoing chemotherapy, radiation therapy or surgery as the first line of treatment were more likely to have a documented DRE 6 months prior to treatment.

CONCLUSION

EHRs contain valuable unstructured information and with NLP, it is feasible to accurately and efficiently identify quality metrics with current documentation clinician workflow.

Direct mechanical characterization of prostate tissue-a systematic review

BACKGROUND

Direct mechanical characterization of tissue is the application of engineering techniques to biological tissue to ascertain stiffness or elasticity, which can change in response to disease states. A number of papers have been published on the application of these techniques to prostate tissue with a range of results reported. There is a marked variability in the results depending on testing techniques and disease state of the prostate tissue. We aimed to clarify the utility of direct mechanical characterization of prostate tissue in identifying disease states.

METHODS

A systematic review of the published literature regarding direct mechanical characterization of prostate tissue was undertaking according to PRISMA guidelines.

RESULTS

A variety of testing methods have been used, including compression, indentation, and tensile testing, as well as some indirect testing techniques, such as shear-wave elastography. There is strong evidence of significant stiffness differences between cancerous and non-cancerous prostate tissue, as well as correlations with prostate cancer stage. There is a correlation with increasing prostate stiffness and increasing lower urinary tract symptoms in patients with benign prostate hyperplasia. There is a wide variation in the testing methods and protocols used in the literature making direct comparison between papers difficult. Most studies utilise ex-vivo or cadaveric tissue, while none incorporate in vivo testing.

CONCLUSION

Direct mechanical assessment of prostate tissue permits a better understanding of the pathological and physiological changes that are occurring within the tissue. Further work is needed to include prospective and in vivo data to aid medical device design and investigate non-surgical methods of managing prostate disease.

The diagnostic test accuracy of rectal examination for prostate cancer diagnosis in symptomatic patients: a systematic review

Background

Prostate cancer is the most common cancer in men in the UK. NICE guidelines on recognition and referral of suspected cancer, recommend performing digital rectal examination (DRE) on patients with urinary symptoms and urgently referring if the prostate feels malignant. However, this is based on the results of one case control study, so it is not known if DRE performed in primary care is an accurate method of detecting prostate cancer.

Methods

The aim of this review is to ascertain the sensitivity, specificity, positive and negative predictive value of DRE for the detection of prostate cancer in symptomatic patients in primary care.

CENTRAL, MEDLINE, EMBASE and CINAHL databases were searched in august 2015 for studies in which a DRE was performed in primary care on symptomatic patients and compared against a reference diagnostic procedure.

Results

Four studies were included with a total of 3225 patients. The sensitivity and specificity for DRE as a predictor of prostate cancer in symptomatic patients was 28.6 and 90.7%, respectively. The positive and negative predictive values were 42.3 and 84.2%, respectively.

Conclusion

This review found that DRE performed in general practice is accurate, and supports the UK NICE guidelines that patients with a malignant prostate on examination are referred urgently for suspected prostate cancer. Abnormal DRE carried a 42.3% chance of malignancy, above the 3% risk threshold which NICE guidance suggests warrants an urgent referral. However this review questions the benefit of performing a DRE in primary care in the first instance, suggesting that a patient’s risk of prostate cancer based on symptoms alone would warrant urgent referral even if the DRE feels normal.

Actual Contribution of Free to Total PSA Ratio in Prostate Diseases Differentiation

OBJECTIVES

To determine significance and sensitivity of the Free to Total prostate specific antigen (PSA) ratio (%fPSA) in diagnosis of prostate cancer and to correlate its sensitivity and specificity with diagnosis.

METHODS

Research included 220 patients, who had indication for biopsy (Clinic for Urology, University Clinical Center Sarajevo).

RESULTS

Average age of patients was 64.6 ± 8.1 years. Kruskal Wallis test indicates that there is a significant difference in age in relation to the diagnosis (KW χ²=12.508; p=0.006). The correlation between the %fPSA level and diagnosis is positive and statistically significant (r=0.211; p=0.002) in the sense that cancer patients have the lowest %fPSA. Analysis of the sensitivity at 95% specificity of %fPSA compared to particular diagnosis shows the highest sensitivity for prostate cancer - 20.61% (8.35-31.02) with statistically significant AUC p<0.05. Analysis of %fPSA test in detecting prostate cancer, at cut-off values ≤ 0.16, shows a sensitivity of 72.3% and specificity of 50.4 (at cut-off values <0.07, sensitivity is 8.4%, and specificity is 97.8%).

CONCLUSION

PSA is organ specific but not cancer specific marker, whose total value, as well as the %fPSA serve as a basis, with a digitorectal exam, in the detection of prostate cancer. By increasing the cut-off values sensitivity of %fPSA increases and specificity decreases. %fPSA has a relative importance in the detection of prostate cancer, and should not be used as a guideline, without prior clinical examination.

Multivariable risk-based patient selection for prostate biopsy in a primary health care setting: referral rate and biopsy results from a urology outpatient clinic

Background

According to their guidelines, Dutch general practitioners (GPs) refer men with prostate-specific antigen (PSA) level ≥3.0 ng/mL to the urologist for risk-based patient selection for prostate biopsy using the Rotterdam Prostate Cancer Risk Calculator (RPCRC). Use of the RPCRC in primary care could optimize the diagnostic pathway even further by reducing unnecessary referrals. To investigate this, we calculated the risk and assessed the rate of men referred to the urologist with PSA level ≥3.0 ng/mL by implementing the RPCRC in a primary health care setting.

Methods

In January 2014, an exploratory study was initiated in collaboration with the primary health care facility of the GP laboratory in Rotterdam. GPs were given the possibility to refer men with a suspicion of prostate cancer (PCa) or a screening wish to this primary care facility (STAR-SHL) where further assessment was performed by specially trained personnel. Risk-based advice on referral to the urologist was given to the GP on the basis of the RPCRC results. If requested, advice on the treatment of lower urinary tract symptoms (LUTS) was provided. All men signed informed consent.

Results

Between January 2014 and September 2017, a total of 243 men, median age 64 [interquartile range (IQR), 57-70] years were referred for a consultation at the primary care facility. Of the 108 men with PSA level ≥3.0 ng/mL and a referral related to PCa, GPs were advised to refer 58 men to the urologist (54%). Of the men with available follow-up (FU) data [n=187, median FU, 16 (IQR, 9-25) months] 54 men were considered high-risk (i.e., had an elevated risk of PCa as calculated by the RPCRC). Of these men, 51 (94%) were actually referred to secondary care by their GP, and so far 38 men underwent biopsy. PCa was detected in 30 men [47% had Gleason score (GS) ≥3+4 PCa], translating to an overall positive predictive value (PPV) of 79%. Within the available FU time, 2 out of 38 (5%) men with PSA level ≥3.0 ng/mL which were considered low-risk have been diagnosed with GS 3+3 PCa.

Conclusions

Risk-stratification with the RPCRC in a primary health care setting could prevent almost half of referrals of men with PSA level ≥3.0 ng/mL to the urologist. In more than three-quarters of men referred for prostate biopsy, the suspicion of PCa was confirmed and almost half of men had clinically significant PCa (GS ≥3+4 PCa). These data show a huge potential for multivariable risk-stratification in primary care.

The 4Kscore blood test accurately identifies men with aggressive prostate cancer prior to prostate biopsy with or without DRE information

INTRODUCTION

The 4Kscore Test is a prebiopsy blood test that incorporates four prostate protein biomarkers along with patient clinical information to determine a man's risk for high-grade, aggressive (Gleason ≥7) prostate cancer. However, some men likely to benefit from the test may be seen in primary care settings where the digital rectal examination (DRE) information is not always obtained. In this study, we assessed the clinical validity of the 4Kscore Test when the DRE information was not included in the algorithm.

METHODS

The Prospective 4Kscore Validation Study enrolled 1012 men scheduled for prostate biopsy across 26 urology practices in the United States. The 4Kscore was calculated for each patient with and without DRE information. The primary outcome was Gleason ≥7 prostate cancer on prostate biopsy. The contribution of DRE to the predictive accuracy of the test was evaluated by area under the receiver operating curve (AUC-ROC), risk calibration and clinical consequences.

RESULTS

High-grade, aggressive prostate cancer was found in 231 (23%) of the 1012 patients. Both versions of the 4Kscore Test, with and without DRE, showed excellent discrimination (AUC=0.821 with DRE and AUC=0.818 without DRE input) and excellent calibration. No clinically significant difference was found between the two versions of the 4Kscore.

CONCLUSIONS

The 4Kscore Test algorithm, whether DRE findings are available or not, performs well in predicting a man's risk of high-grade, aggressive prostate cancer. Patients who are suspected of having aggressive prostate cancer can safely have their risk better defined by 4Kscore even if a DRE has not been performed recently.

Assessment of Tumor Stiffness With Shear Wave Elastography in a Human Prostate Cancer Xenograft Implantation Model

OBJECTIVES

To investigate the stiffness of human prostate cancer in a xenograft implantation model using shear wave elastography and compare the pathologic features of tumors with varying elasticity.

METHODS

Human prostate cancer DU-145 cells were injected into 24 nude male mice. The mice were divided into 3 groups according to the time of transplantation (6, 8, and 10 weeks). The volume, elasticity, and Young modulus of tumors were recorded by 2-dimensional sonography and shear wave elastography. The tumors were collected for pathologic analyses: hematoxylin-eosin staining, Ponceau S, and aniline staining were used to stain collagen and elastic fibers, and picric acid-sirius red staining was used to indicate type I and III collagen. The area ratios of collagen I/III were calculated. The correlation between the Young modulus of the tumor and area ratio of collagen I/III were evaluated. Immunohistochemistry of vimentin and α-smooth muscle actin was performed.

RESULTS

Nineteen tumors in 3 groups were collected. The volume and mean Young modulus increased with the time of transplantation. There were more collagen fibers in the stiff tumors, and there were significant differences in the area ratios of collagen I/III between groups 1 (mean ± SD, 0.50 ± 0.17) and 3 (1.97 ± 0.56; P < .01). The Young modulus of the tumors showed a very significant correlation with the area ratios of collagen I/III (r = 0.968; P < .05). The expression level of α-smooth muscle actin protein was higher in group 3 than in the other groups, but differences in vimentin expression were barely seen.

CONCLUSIONS

Shear wave elastography is a novel useful technology for showing the elasticity of human prostate cancer xenograft implantation tumors. Collagen fibers, especially collagen type I, play a crucial role in the elasticity in the human prostate cancer xenograft implantation model.

Application of transrectal ultrasound-guided repeat needle biopsy in the diagnosis of prostate cancer in Chinese population: A retrospective study

BACKGROUND

Transrectal ultrasound-guided repeat needle biopsy (TUGRNB) is widely used for diagnosis of prostate cancer (PCa). However, significance of TUGRNB in Chinese population was rarely reported. A retrospective study was conducted to evaluate the significance of TUGRNB applied in prediction of PCa in Chinese population.

MATERIALS AND METHODS

A total of 960 from January 2009 to December 2012 were included. Repeat needle biopsy rate and PCa positive detection rate were evaluated. Relationship between prostate specific antigen (PSA) levels and PCa positive rates was analyzed.

RESULTS

PCa positive detection rate after initial needle biopsy was 28.4%, which was lower than the rate of repeat needle biopsy (40%). The rate for immediate transurethral resection (TUR), surgery after initial needle biopsy, was 27.1%, however with a low PCa positive detection rate (0.66%). The repeat needle biopsy rate was lower compared with the initial biopsy rate (P < 0.05). Meanwhile, immediate TUR rate was significantly higher than that of the repeat needle biopsy rate (P < 0.05). Among the three groups, the PCa positive detection rate in repeat needle biopsy group was the highest. In subgroups with different PSA levels, the PCa positive rate increased with the elevation of PSA level. In cases with PSA > 20 ng/ml, PCa positive rate was significantly higher than those with PSA < 20 ng/ml (P < 0.05).

CONCLUSION

PCa positive detection rate following repeat needle biopsy in Chinese population was higher, although the repeated needle biopsy rate was still in a low level. TUGRNB should attract more attention in the diagnosis of PCa.

Role of multiparametric MRI in the diagnosis of prostate cancer: update

Prostate cancer is the most common malignancy of the male gender. The role of magnetic resonance imaging has evolved very rapidly over the years to be currently recognized as a fundamental tool in the diagnosis, treatment and follow-up of prostate cancer.