Comparative evaluation of urinary PCA3 and TMPRSS2: ERG scores and serum PHI in predicting prostate cancer aggressiveness

Combining prostate health index and multiparametric magnetic resonance imaging in estimating the histological diameter of prostate cancer

BACKGROUND

Although multiparametric magnetic resonance imaging (mpMRI) is widely used to assess the volume of prostate cancer, it often underestimates the histological tumor boundary. The aim of this study was to evaluate the feasibility of combining prostate health index (PHI) and mpMRI to estimate the histological tumor diameter and determine the safety margin during treatment of prostate cancer.

METHODS

We retrospectively enrolled 72 prostate cancer patients who underwent radical prostatectomy and had received PHI tests and mpMRI before surgery. We compared the discrepancy between histological and radiological tumor diameter stratified by Prostate Imaging-Reporting and Data System (PI-RADS) score, and then assessed the influence of PHI on the discrepancy between low PI-RADS (2 or 3) and high PI-RADS (4 or 5) groups.

RESULTS

The mean radiological and histological tumor diameters were 1.60 cm and 2.13 cm, respectively. The median discrepancy between radiological and histological tumor diameter of PI-RADS 4 or 5 lesions was significantly greater than that of PI-RADS 2 or 3 lesions (0.50 cm, IQR (0.00-0.90) vs. 0.00 cm, IQR (-0.10-0.20), p = 0.02). In the low PI-RADS group, the upper limit of the discrepancy was 0.2 cm; so the safety margin could be set at 0.1 cm. In the high PI-RADS group, the upper limits of the discrepancy were 1.2, 1.6, and 2.2 cm in men with PHI < 30, 30-60, and > 60; so the safety margin could be set at 0.6, 0.8, and 1.1 cm, respectively.

CONCLUSIONS

Radiological tumor diameter on mpMRI often underestimated the histological tumor diameter, especially for PI-RADS 4 or 5 lesions. Combining mpMRI and PHI may help to better estimate the histological tumor diameter.

Future perspective of focal therapy for localized prostate cancer

Objective

To summarize the recent literature discussing focal therapy for localized prostate cancer.

Methods

A thorough literature review was performed using PubMed to identify recent studies involving focal therapy for the treatment of localized prostate cancer.

Results

In an effort to decrease the morbidity associated with prostate cancer treatment, many urologists are turning to focal therapy as an alternative treatment option. With this approach, the cancer bearing portion of the prostate is targeted while leaving the benign tissue untouched. Multiparametric magnetic resonance imaging remains the gold standard for visualization during focal therapy, but new imaging modalities such as prostate specific membrane antigen/positron emission tomography and contrast enhanced ultrasound are being investigated. Furthermore, several biomarkers, such as prostate cancer antigen 3 and prostate health index, are used in conjunction with imaging to improve risk stratification prior to focal therapy. Lastly, there are several novel technologies such as nanoparticles and transurethral devices that are under investigation for use in focal therapy.

Conclusion

Focal therapy is proving to be a promising option for the treatment of localized prostate cancer. However, further study is needed to determine the true efficacy of these exciting new technologies.

Impact of the MyProstateScore (MPS) Test on the Clinical Decision to Undergo Prostate Biopsy: Results From a Contemporary Academic Practice

OBJECTIVE

To evaluate the association of the MyProstateScore (MPS) urine test on the decision to undergo biopsy in men referred for prostate biopsy in urology practice.

METHODS

MPS testing was offered as an alternative to immediate biopsy in men referred to the University of Michigan for prostate biopsy from October 2013 through October 2016. The primary endpoint was the decision to perform biopsy. The proportion of patients undergoing biopsy was compared to predicted risk scores from the Prostate Cancer Prevention Trial risk calculator (PCPTrc). Analyses were stratified by the use of multiparametric magnetic resonance imaging (mpMRI). The associations of PCPTrc, MPS, and mpMRI with the decision to undergo biopsy were explored in a multivariable logistic regression model.

RESULTS

Of 248 patients, 134 (54%) proceeded to prostate biopsy. MPS was significantly higher in biopsied patients (median 29 vs14, P < .001). The use of biopsy was strongly associated with MPS, with biopsy rates of 26%, 38%, 58%, 90%, and 85% in the first through fifth quintiles, respectively (P < .001). MPS association with biopsy persisted upon stratification by mpMRI. On multivariable analysis, MPS was strongly associated with the decision to undergo biopsy when modeled as both a continuous (odds ratio [OR] 1.05, 95%; confidence interval [CI] 1.04-1.08; <.001) and binary (OR 7.76, 95%; CI 4.14-14.5; P < .001) variable.

CONCLUSION

Many patients (46%) undergoing clinical MPS testing as an alternative to immediate prostate biopsy were able to avoid biopsy. Increasing MPS was strongly associated with biopsy rates. These findings were robust to use of mpMRI.

Preoperative %p2PSA and Prostate Health Index Predict Pathological Outcomes in Patients with Prostate Cancer Undergoing Radical Prostatectomy

To evaluate the predictive accuracy of the %p2PSA and prostate health index (PHI) in predicting aggressive pathological outcomes in patients with prostate cancer (PCa) undergoing radical prostatectomy (RP), we enrolled 91 patients with organ-confined PCa who were treated with robot-assisted RP. p2PSA levels and the PHI were investigated for their ability to predict pathological results. The %p2PSA and PHI were both significantly higher in patients with ≥pT3 disease, high-risk disease, positive surgical margin, or seminal vesical invasion (SVI). In univariable analysis, p2PSA derivatives were significant predictors of the presence of ≥pT3 disease, high-risk disease, positive surgical margin, and SVI. To predict adverse pathological outcomes at a sensitivity of 90%, p2PSA derivatives had higher specificity than standard PSA derivatives. In multivariable analysis, additional increases in the area under the receiver operating characteristic curve (AUC) were observed with the %p2PSA and PHI for ≥pT3 disease, high-risk disease, and positive surgical margin (8.2% and 2.7%, 6.2% and 4.1%, and 8.6% and 5.4%, respectively). A PHI ≥61.26 enhanced the predictive accuracy of the model for SVI by increasing the AUC from 0.624 to 0.819 (p = 0.009). The preoperative %p2PSA and PHI accurately predict adverse pathological results and are useful for decision-making.

The long non-coding RNA PCA3: an update of its functions and clinical applications as a biomarker in prostate cancer

Prostate cancer antigen 3 (PCA3) is an overexpressed prostate long non-coding RNA (lncRNA), transcribed from an intronic region at the long arm of human chromosome 9q21–22. It has been described that PCA3 modulates prostate cancer (PCa) cell survival through modulating androgen receptor (AR) signaling, besides controlling the expression of several androgen responsive and cancer-related genes, including epithelial–mesenchymal transition (EMT) markers and those regulating gene expression and cell signaling. Also, PCA3 urine levels have been successfully used as a PCa diagnostic biomarker. In this review, we have highlighted recent findings regarding PCA3, addressing its gene structure, putative applications as a biomarker, a proposed origin of this lncRNA, roles in PCa biology and expression patterns. We also updated data regarding PCA3 interactions with cancer-related miRNAs and expression in other tissues and diseases beyond the prostate. Altogether, literature data indicate aberrant expression and dysregulated activity of PCA3, suggesting PCA3 as a promising relevant target that should be even further evaluated on its applicability for PCa detection and management.

Prostate Health Index improves multivariable risk prediction of aggressive prostate cancer

OBJECTIVE

To examine the use of the Prostate Health Index (PHI) as a continuous variable in multivariable risk assessment for aggressive prostate cancer in a large multicentre US study.

MATERIALS AND METHODS

The study population included 728 men, with prostate-specific antigen (PSA) levels of 2-10 ng/mL and a negative digital rectal examination, enrolled in a prospective, multi-site early detection trial. The primary endpoint was aggressive prostate cancer, defined as biopsy Gleason score ≥7. First, we evaluated whether the addition of PHI improves the performance of currently available risk calculators (the Prostate Cancer Prevention Trial [PCPT] and European Randomised Study of Screening for Prostate Cancer [ERSPC] risk calculators). We also designed and internally validated a new PHI-based multivariable predictive model, and created a nomogram.

RESULTS

Of 728 men undergoing biopsy, 118 (16.2%) had aggressive prostate cancer. The PHI predicted the risk of aggressive prostate cancer across the spectrum of values. Adding PHI significantly improved the predictive accuracy of the PCPT and ERSPC risk calculators for aggressive disease. A new model was created using age, previous biopsy, prostate volume, PSA and PHI, with an area under the curve of 0.746. The bootstrap-corrected model showed good calibration with observed risk for aggressive prostate cancer and had net benefit on decision-curve analysis.

CONCLUSION

Using PHI as part of multivariable risk assessment leads to a significant improvement in the detection of aggressive prostate cancer, potentially reducing harms from unnecessary prostate biopsy and overdiagnosis.

Does the Prostate Health Index Depend on Tumor Volume?-A Study on 196 Patients after Radical Prostatectomy

The Prostate Health Index (PHI) has been used increasingly in the context of prostate cancer (PCa) diagnostics since 2010. Previous studies have shown an association between PHI and a tumor volume of >0.5 cm³. The aim of this study was to investigate the correlation between PHI and tumor volume as well as the Gleason score. A total of 196 selected patients with prostate cancer treated with radical prostatectomy at our institution were included in our study. The tumor volume was calculated and preoperative serum parameters total prostate-specific antigen (tPSA), free PSA (fPSA), [−2]proPSA, and PHI were evaluated. The association between the pathological findings such as Gleason score, pathological T-stage (pT stage), and tumor volume were evaluated. We further used logistic regression and Cox proportional hazard regression analyses for assessing the association between tumor volume and PHI and for predicting biochemical recurrence. With an area under the curve (AUC) of 0.79, PHI is the most accurate predictor of a tumor volumes >0.5 cm³. Moreover, PHI correlates significantly with the tumor volume (r = 0.588), which is significantly different (p = 0.008) from the correlation of the Gleason score with tumor volume (r = 0.385). PHI correlates more strongly with the tumor volume than does the Gleason score. Using PHI improves the prediction of larger tumor volume and subsequently clinically significant cancer.

Prostate Cancer Detection and Prognosis: From Prostate Specific Antigen (PSA) to Exosomal Biomarkers

Prostate specific antigen (PSA) remains the most used biomarker in the management of early prostate cancer (PCa), in spite of the problems related to false positive results and overdiagnosis. New biomarkers have been proposed in recent years with the aim of increasing specificity and distinguishing aggressive from non-aggressive PCa. The emerging role of the prostate health index and the 4Kscore is reviewed in this article. Both are blood-based tests related to the aggressiveness of the tumor, which provide the risk of suffering PCa and avoiding negative biopsies. Furthermore, the use of urine has emerged as a non-invasive way to identify new biomarkers in recent years, including the PCA3 and TMPRSS2:ERG fusion gene. Available results about the PCA3 score showed its usefulness to decide the repetition of biopsy in patients with a previous negative result, although its relationship with the aggressiveness of the tumor is controversial. More recently, aberrant microRNA expression in PCa has been reported by different authors. Preliminary results suggest the utility of circulating and urinary microRNAs in the detection and prognosis of PCa. Although several of these new biomarkers have been recommended by different guidelines, large prospective and comparative studies are necessary to establish their value in PCa detection and prognosis.

Screening for Prostate Cancer-Beyond Total PSA, Utilization of Novel Biomarkers

Urology has been beset by several major trends that have shifted the entire paradigm for prostate cancer screening. These stem from a backlash against overdiagnosis and overtreatment due to prostate-specific antigen (PSA)-based screening efforts and have led national societies to modify their guidelines. More importantly, the public outcry has shifted the focus of early detection from an effort to diagnose any and all prostate cancers to an effort to diagnose clinically significant prostate cancers at an early stage. This review provides an update on contemporary biomarkers for prostate cancer that may be used to supplement PSA-based screening approaches.

Emerging biomarkers in the detection and prognosis of prostate cancer

The prostate-specific antigen (PSA) is currently the most used tumor marker in the early detection of the prostate cancer (PCa), despite its low specificity and low negative predictive value. New biomarkers, including urine prostate cancer gene 3 (PCA3) score, Prostate Health Index (PHI), and the four-kallikrein panel, have been investigated during recent years especially with the aim of detecting aggressive PCa. Results suggest the ability of these biomarkers to improve the specificity of PSA in the detection of PCa, although there are not enough results directly comparing these biomarkers to know their complementarity. The relationship with PCa aggressiveness seems to be confirmed for PHI and for the four-kallikrein panel, but not for PCA3 score. However, available results suggest that emerging biomarkers may be useful as part of a multivariable approach for the screening and prognosis of PCa. Nevertheless, larger prospective studies comparing these biomarkers are necessary to evaluate definitely their value in the management of early PCa.

Prostate Health Index (PHI) Predicts High-stage Pathology in African American Men

OBJECTIVE

To evaluate the association between the Prostate Health Index (PHI) and adverse pathology in a cohort of African American (AA) men undergoing radical prostatectomy.

MATERIALS AND METHODS

Eighty AA men with prostate-specific antigen (PSA) of 2-10 ng/mL underwent measurement of PSA, free PSA (fPSA), and p2PSA prior to radical prostatectomy. PHI was calculated as [(p2PSA/fPSA) × (PSA)(½)]. Biomarker association with pT3 disease was assessed using logistic regression, and covariates were added to a baseline multivariable model including digital rectal examination. Biomarker ability to predict pT3 disease was measured using the area under the receiver operator characteristic curve.

RESULTS

Sixteen men (20%) demonstrated pT3 disease on final pathology. Mean age, PSA, and %fPSA were similar in men with and without pT3 disease (all P  >  .05), whereas PHI was significantly greater in men with pT3 disease (mean 57.2 vs 46.6, P  =  .04). Addition of PHI to the baseline multivariable model improved discriminative ability by 12.9% (P  =. .04) and yielded greater diagnostic accuracy than models, including other individual biomarkers.

CONCLUSION

In AA men with PSA of 2-10 ng/mL, PHI was predictive of pT3 prostate cancer and may help to identify men at increased risk of adverse pathology. Additional studies are needed to substantiate these findings and identify appropriate thresholds for clinical use.

Detection of Core2 β-1,6-N-Acetylglucosaminyltransferase in Post-Digital Rectal Examination Urine Is a Reliable Indicator for Extracapsular Extension of Prostate Cancer

To identify appropriate candidates for aggressive treatment such as radical prostatectomy or radiation therapy of localized prostate cancer (PCa), novel predictive biomarkers of PCa aggressiveness are essential. Core2 β-1,6-N-acetylglucosaminyltransferase-1 (GCNT1) is a key enzyme that forms core 2-branched O-glycans. Its expression is associated with the progression of several cancers. We established a mouse IgG monoclonal antibody (mAb) against GCNT1 and examined the relationship of GCNT1 expression to the clinicopathological status of PCa. Paraffin-embedded PCa specimens were analyzed by immunohistochemistry for GCNT1 expression using a newly established mouse anti-GCNT1 mAb by ourselves. GCNT1-positive tumor showed significantly higher Gleason score and larger tumor volume. The number of GCNT1-positive cases was significantly lower in cases of organ-confined disease than in cases of extracapsular extension. GCNT1-negative tumors were associated with significantly better prostate-specific antigen (PSA)-free survival compared with GCNT1-positive tumors. Multivariate analysis revealed that detection of GCNT1 expression was an independent risk factor for PSA recurrence. We established new methods for GCNT1 detection from PCa specimens. Immunoblotting was used to examine post-digital rectal examination (DRE) urine from PCa patients. Over 90% of GCNT1-positive PCa patients with high concentrations of PSA showed extracapsular extension. In conclusion, GCNT1 expression closely associates with the aggressive potential of PCa. Further research aims to develop GCNT1 detection in post-DRE urine as a marker for PCa aggressiveness.

High PCA3 scores in urine correlate with poor-prognosis factors in prostate cancer patients

BACKGROUND

To improve the prediction of prostate cancer (PCA) risk and pathological type of PCA by non-invasive approaches before performing prostatic biopsy are the current challenges for the management of PCA. The aim of this present study was evaluate the clinical validity of prostate cancer associated 3 (PCA3) gene in the prediction of PCA and the correlations between the PCA3 level and prognostic factors.

METHODS

A total of 207 patients with suspected prostate cancer in Ningbo No. 2 hospital between June 2012 and July 2014 were enrolled in this study. All patients included underwent prostate biopsy under the direction of digital rectal examination (DRE) and were divided into PCA group and no evidence of malignancy (NEM) group according to the pathological diagnosis. We analyzed the association between PCA3 score and indicators of prognosis (Gleason score, percentage of positive cores and clinical stage) by multivariate analysis.

RESULTS

The levels of total prostate-specific antigen (t-PSA), prostate health index (PHI) and PCA3 score in patients with PCA were significantly higher than those in NEM group (P<0.05). In PCA group, PHI value and t-PSA were both factors significantly correlated with high Gleason score and clinical stage (P<0.05). A high PCA3 score in urine was significantly correlated with a high Gleason score, % positive cores and an advanced clinical stage (P<0.05).

CONCLUSION

PCA3 score might be one of useful diagnostic tools for determining suitable therapeutic programs for PCa and predicting the prognosis.

Urinary biomarkers for prostate cancer

PURPOSE OF REVIEW

The field of urology has been beset by several major trends that have affected the early detection of prostate cancer. These stem primarily from a backlash against overdiagnosis due to prostate specific antigen-based screening efforts and are epitomized by the US Preventive Services Task Force giving prostate specific antigen-based prostate cancer screening a 'D' recommendation. Consequently, the active surveillance strategy for low-risk prostate cancer has become commonplace, leading many to ask how best to follow these patients. More importantly, this public outcry has shifted the focus of early detection from an effort to diagnose any and all prostate cancers to an effort to diagnose only 'high-risk' cancer. Along with a trend for minimally invasive procedures, these forces have challenged the early detection field to more efficiently identify clinically significant prostate cancers at an early stage while limiting the number of biopsies.

RECENT FINDINGS

With US Food and Drug Administration approval, prostate cancer antigen 3 has emerged as the first bona-fide urinary biomarker for prostate cancer. Using the same platform, investigators have developed a second urinary test based on TMPRSS2:erg fusion. Recent literature supports the use of these biomarkers as a combined panel that improves risk evaluation in the setting of prostate cancer detection. Early works for applying urinary biomarkers for active surveillance are underway. Other biomarkers in the pipeline will require further prevalidation and validation work.

SUMMARY

Recent literature would support that urinary biomarkers have a clear role to supplement risk evaluation for men undergoing prostate biopsy and for prognostication.

Diagnostic performance of expression of PCA3, Hepsin and miR biomarkers inejaculate in combination with serum PSA for the detection of prostate cancer

BACKGROUND AND METHODS

Here, we report on the evaluation of the diagnostic performance of ejaculate-derived PCA3, Hepsin, and miRNAs to complement serum PSA to detect prostate cancer. cDNA was prepared from 152 candidate specimens following RNA isolation and amplification for PSA, PCA3 and Hepsin qPCR, with 66 having adequate RNA for all three assays. Small RNA sequencing and examination of PCa-associated miRNAs miR-200b, miR-200c, miR-375 and miR-125b was performed on 20 specimens. We compared findings from prostate biopsies using D'Amico and PRIAS classifications and in relation to whole gland histopathology following radical prostatectomy. Multivariate logistic regression modeling and clinical risk (incorporating standard clinicopathological variables) were performed for all ejaculate-based markers.

RESULTS

While Hepsin alone was not of predictive value, the Hepsin:PCA3 ratio together with serum PSA, expressed as a univariate composite score based on multivariate logistic regression, was shown to be a better predictor than PSA alone of prostate cancer status (AUC 0.724 vs. 0.676) and risk, using D'Amico (AUC 0.701 vs. 0.680) and PRIAS (AUC 0.679 vs. 0.659) risk stratification criteria as classified using prostate biopsies. It was also possible to analyse a subgroup of patients for miRNA expression with miR-200c (AUC 0.788) and miR-375 (AUC 0.758) showing best single marker performance, while a combination of serum PSA, miR-200c, and miR-125b further improved prediction for prostate cancer status when compared to PSA alone determined by biopsy (AUC 0.869 vs. 0.672; P < 0.05), and risk (D'Amico/PRIAS) as well as by radical prostatectomy histology (AUC 0.809 vs. 0.690). For prostate cancer status by biopsy, at a sensitivity of 90%, the specificity of the test increased from 11% for PSA alone to 67% for a combination of PSA, miR-200c, and miR-125b.

CONCLUSIONS

These results show that use of a combination of different types of genetic markers in ejaculate together with serum PSA are at least as sensitive as those reported in DRE urine. Furthermore, a combination of serum PSA and selected miRNAs improved prediction of prostate cancer status. This approach may be helpful in triaging patients for MRI and biopsy, when confirmed by larger studies.

Serum markers in prostate cancer detection

PURPOSE OF REVIEW

Prostate-specific antigen (PSA) testing provides significant benefits by reducing prostate cancer mortality, but also leads to important harms by detecting clinically insignificant cancers. Hence, there are urgent needs for complementary tools for middle-aged men with modest PSA elevations in blood. This review includes research on prostate cancer biomarkers in blood published from March 2013 through August 2014.

RECENT FINDINGS

Research progress has been made mainly on PSA as a predictive marker and in the field of kallikrein-based tests: [-2] proPSA, the prostate health index, and a panel of four kallikrein markers. As men with PSA levels below age-median are at very low 20-year risk of metastatic prostate cancer, individualized screening intervals, based on PSA levels, may help in reducing screening costs, prostate biopsies, and detection of insignificant cancer. Statistical models based on kallikrein-markers in blood improve the specificity at modestly elevated PSA (2-10 ng/ml), eliminate unnecessary biopsies, and help selecting men at risk of significant prostate cancer for biopsy or imaging.

SUMMARY

Individualized, risk-adapted PSA testing intervals and reflex-testing of kallikrein-markers for men with modestly increased PSA values may decrease the harms of screening. However, the clinical value of the proposed testing algorithms and additional tests awaits definitive confirmation in prospective trials.