Comprehensive report on prostate cancer misclassification by 16 currently used low-risk and active surveillance criteria

Can we predict pathology without surgery? Weighing the added value of multiparametric MRI and whole prostate radiomics in integrative machine learning models

OBJECTIVE

To test the ability of high-performance machine learning (ML) models employing clinical, radiological, and radiomic variables to improve non-invasive prediction of the pathological status of prostate cancer (PCa) in a large, single-institution cohort.

METHODS

Patients who underwent multiparametric MRI and prostatectomy in our institution in 2015-2018 were considered; a total of 949 patients were included. Gradient-boosted decision tree models were separately trained using clinical features alone and in combination with radiological reporting and/or prostate radiomic features to predict pathological T, pathological N, ISUP score, and their change from preclinical assessment. Model behavior was analyzed in terms of performance, feature importance, Shapley additive explanation (SHAP) values, and mean absolute error (MAE). The best model was compared against a naïve model mimicking clinical workflow.

RESULTS

The model including all variables was the best performing (AUC values ranging from 0.73 to 0.96 for the six endpoints). Radiomic features brought a small yet measurable boost in performance, with the SHAP values indicating that their contribution can be critical to successful prediction of endpoints for individual patients. MAEs were lower for low-risk patients, suggesting that the models find them easier to classify. The best model outperformed (p ≤ 0.0001) clinical baseline, resulting in significantly fewer false negative predictions and overall was less prone to under-staging.

CONCLUSIONS

Our results highlight the potential benefit of integrative ML models for pathological status prediction in PCa. Additional studies regarding clinical integration of such models can provide valuable information for personalizing therapy offering a tool to improve non-invasive prediction of pathological status.

CLINICAL RELEVANCE STATEMENT

The best machine learning model was less prone to under-staging of the disease. The improved accuracy of our pathological prediction models could constitute an asset to the clinical workflow by providing clinicians with accurate pathological predictions prior to treatment.

KEY POINTS

• Currently, the most common strategies for pre-surgical stratification of prostate cancer (PCa) patients have shown to have suboptimal performances. • The addition of radiological features to the clinical features gave a considerable boost in model performance. Our best model outperforms the naïve model, avoiding under-staging and resulting in a critical advantage in the clinic. •Machine learning models incorporating clinical, radiological, and radiomics features significantly improved accuracy of pathological prediction in prostate cancer, possibly constituting an asset to the clinical workflow.

Diagnostic Accuracy of Contemporary Selection Criteria in Prostate Cancer Patients Eligible for Active Surveillance: A Bayesian Network Meta-Analysis

Background

Several active surveillance (AS) criteria have been established to screen insignificant prostate cancer (insigPCa, defined as organ confined, low grade and small volume tumors confirmed by postoperative pathology). However, their comparative diagnostic performance varies. The aim of this study was to compare the diagnostic accuracy of contemporary AS criteria and validate the absolute diagnostic odds ratio (DOR) of optimal AS criteria.

Methods

First, we searched Pubmed and performed a Bayesian network meta-analysis (NMA) to compare the diagnostic accuracy of contemporary AS criteria and obtained a relative ranking. Then, we searched Pubmed again to perform another meta-analysis to validate the absolute DOR of the top-ranked AS criteria derived from the NMA with two endpoints: insigPCa and favorable disease (defined as organ confined, low grade tumors). Subgroup and meta-regression analyses were conducted to identify any potential heterogeneity in the results. Publication bias was evaluated.

Results

Seven eligible retrospective studies with 3,336 participants were identified for the NMA. The diagnostic accuracy of AS criteria ranked from best to worst, was as follows: Epstein Criteria (EC), Yonsei criteria, Prostate Cancer Research International: Active Surveillance (PRIAS), University of Miami (UM), University of California-San Francisco (UCSF), Memorial Sloan-Kettering Cancer Center (MSKCC), and University of Toronto (UT). I² = 50.5%, and sensitivity analysis with different insigPCa definitions supported the robustness of the results. In the subsequent meta-analysis of DOR of EC, insigPCa and favorable disease were identified as endpoints in ten and twenty-two studies, respectively. The pooled DOR for insigPCa and favorable disease were 0.44 (95%CI, 0.31–0.58) and 0.66 (95%CI, 0.61–0.71), respectively. According to a subgroup analysis, the DOR for favorable disease was significantly higher in US institutions than that in other regions. No significant heterogeneity or evidence of publication bias was identified.

Conclusions

Among the seven AS criteria evaluated in this study, EC was optimal for positively identifying insigPCa patients. The pooled diagnostic accuracy of EC was 0.44 for insigPCa and 0.66 when a more liberal endpoint, favorable disease, was used.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], PROSPERO [CRD42020157048].

Methylation Markers in Prostate Biopsies Are Prognosticators for Late Biochemical Recurrence and Therapy after Surgery in Prostate Cancer Patients

After diagnosis of prostate cancer is confirmed by a positive biopsy, the tumor may be surgically removed via radical prostatectomy (RP). However, many prostate cancer patients experience biochemical recurrence after surgery and/or undergo salvage radiotherapy or hormone therapy. Timely treatment is required to prevent the spread of disease in these cases, and biopsy tissue may hold potential for disease prognostication before surgery is ever performed. We previously developed a prognostic multigene methylation panel in RP specimens, including APC, CRIP3, HOXD3, and TGFB2. In the current study, this panel was applied to a cohort of biopsy specimens (n = 86), which were assessed for DNA methylation using the real-time quantitative PCR-based multiplex MethyLight. The biopsy-based methylation panel is significantly associated with biochemical recurrence when combined with the current clinical parameter of prostate-specific antigen (PSA) levels at diagnosis and is able to prognosticate the initiation of salvage radiotherapy, where it outperforms PSA, and/or hormone therapy after RP. In addition, this methylation panel is significantly associated with late recurrence occurring within 5 and 7 years after surgery, when combined with PSA at diagnosis. Combining DNA methylation and clinicopathologic markers at the biopsy stage will not only increase their prognostic ability but will also ensure effective patient management.

Trans-Perineal Template-Guided Mapping Biopsy vs. Freehand Trans-Perineal Biopsy in Chinese Patients With PSA < 20 ng/ml: Similar Cancer Detection Rate but Different Lesion Detection Rate

The present study aimed to investigate the diagnostic efficacy and the regional location of prostate cancer (PCa) as well as the accuracy of assessment between trans-perineal template-guided mapping biopsy (TTMB) and freehand trans-perineal biopsy (FTPB) for men with PSA < 20 ng/ml. Thus, we evaluated 623 consecutive patients with PSA < 20 ng/ml who had prostate biopsies in our institute between July 2017 and September 2018. Patients were divided into two groups based on different biopsy methods: 217 (34.83%) patients with TTMB and 406 (65.17%) with FTPB. Thirty six patients with TTMB and 80 with FTPB had continued undergone radical prostatectomy after a cancer diagnosis. Then the Gleason score of the biopsy and the post-radical prostatectomy specimens in each patient were compared. Overall, the PCa detection rate was 34.35%. There was no significant difference in PCa detection rate between TTMB and FTPB (35.48 vs. 33.74%, respectively; p = 0.663). Besides, the detection rate of significant PCa (Gleason score ≥ 7) in TTMB was 29.03% while FTPB was 23.89% (p = 0.162). The detection rate at the apex of the prostate was higher than the detection rate at the base of the prostate (9.80 vs. 5.79%; p < 0.01) when performing the TTMB. The FTPB would miss 10% of the positive diagnosis and almost half of the lesions. The upgraded of Gleason score from biopsy to post-radical prostatectomy was 16.67% with the TTMB and 36.25% with the FTPB (p = 0.034). The TTMB had a similar cancer detection rate, but a higher lesion detection rate and more accuracy in assess the actual Gleason score when comparing to FTPB for men with PSA < 20 ng/ml. By performing a 20-core TTMB, the cancer detection rate at the apex of the prostate was higher than the base.

Circulating miRNAs in localized/locally advanced prostate cancer patients after radical prostatectomy and radiotherapy

BACKGROUND

Overtreatment is a well-known clinical challenge in local prostate cancer (PCa). Although risk assessment models have contributed to a better stratification of patients with local PCa, a tailored management is still in its infancy. Over the last few decades, microRNAs (miRNAs) have shown promising results as biomarkers in PCa. The aim of this study was to investigate circulating miRNAs after management of local PCa.

METHODS

The relative expression of four miRNAs (miRNA-21, -93, -125b, and miRNA-221) was assessed in plasma from 149 newly diagnosed patients with local or locally advanced PCa. Real-time polymerase chain reaction was used for analysis. A baseline sample at time of diagnosis and a follow-up sample after 6 months were assessed. The patients were grouped in an interventional cohort (radical prostatectomy, curative intent radiotherapy, or androgen-deprivation therapy alone) and an observational cohort (watchful waiting or active surveillance).

RESULTS

In the interventional cohort, levels of both miRNA-93 and miRNA-221 were significantly lower in the follow-up samples compared to baseline z = -2.738, P = 0.006, and z = -4.498, P < 0.001, respectively. The same observation was recorded for miRNA-125b in the observational cohort (z = -2.656, P = 0.008). Both miRNA-125b and miRNA-221 were correlated with risk assessment r = 0.23, P = 0.015, and r = 0.203, P = 0.016 respectively, while miRNA-93 showed tendency to significant correlation with the prostatectomy Gleason score (r = 0.276, P = 0.0576).

CONCLUSIONS

The current results indicate a possible role of miRNA-93 and miRNA-221 in disease monitoring in localized and locally advanced PCa. Larger studies are warranted to assess the clinical impact of these biomarkers.

ESTIMATING AND COMPARING CANCER PROGRESSION RISKS UNDER VARYING SURVEILLANCE PROTOCOLS

Outcomes after cancer diagnosis and treatment are often observed at discrete times via doctor-patient encounters or specialized diagnostic examinations. Despite their ubiquity as endpoints in cancer studies, such outcomes pose challenges for analysis. In particular, comparisons between studies or patient populations with different surveillance schema may be confounded by differences in visit frequencies. We present a statistical framework based on multistate and hidden Markov models that represents events on a continuous time scale given data with discrete observation times. To demonstrate this framework, we consider the problem of comparing risks of prostate cancer progression across multiple active surveillance cohorts with different surveillance frequencies. We show that the different surveillance schedules partially explain observed differences in the progression risks between cohorts. Our application permits the conclusion that differences in underlying cancer progression risks across cohorts persist after accounting for different surveillance frequencies.

Novel Biomarkers for Prostate Cancer Detection and Prognosis

Prostate cancer (PCa) remains as one of the most controversial issues in health care because of the dilemmas related to screening using Prostate Specific Antigen (PSA). A high number of false positive biopsies and an elevated rate of overdiagnosis are the main problems associated with PSA. New PCa biomarkers have been recently proposed to increase the predictive value of PSA. The published results showed that PCA3 score, Prostate Health Index and 4Kscore can reduce the number of unnecessary biopsies, outperforming better than PSA and the percentage of free PSA. Furthermore, 4Kscore provides with high accuracy an individual risk for high-grade PCa. High values of PHI are also associated with tumor aggressiveness. In contrast, the relationship of PCA3 score with aggressiveness remains controversial, with studies showing opposite conclusions. Finally, the development of molecular biology has opened the study of genes, among them TMPRSS2:ERG fusion gene and miRNAs, in PCa detection and prognosis.

Epigenetic risk score improves prostate cancer risk assessment

BACKGROUND

Early detection of aggressive prostate cancer (PCa) remains crucial for effective treatment of patients. However, PCa screening remains controversial due to a high rate of overdiagnosis and overtreatment. To better reconcile both objectives, more effective methods for assessing disease severity at the time of diagnosis are needed.

METHODS

The relationship between DNA-methylation and high-grade PCa was examined in a cohort of 102 prospectively enrolled men who received standard 12-core prostate biopsies. EpiScore, an algorithm that quantifies the relative DNA methylation intensities of GSTP1, RASSF1, and APC in prostate biopsy tissue, was evaluated as a method to compensate for biopsy under-sampling and improve risk stratification at the time of diagnosis.

RESULTS

DNA-methylation intensities of GSTP1, RASSF1, and APC were higher in biopsy cores from men diagnosed with GS ≥ 7 cancer compared to men with diagnosed GS 6 disease. This was confirmed by EpiScore, which was significantly higher for subjects with high-grade biopsies and higher NCCN risk categories (both P < 0.001). In patients diagnosed with GS ≥ 7, increased levels of DNA-methylation were present, not only in the high-grade biopsy cores, but also in other cores with no or low-grade disease (P < 0.001). By combining EpiScore with traditional clinical risk factors into a logistic regression model, the prediction of high GS reached an AUC of 0.82 (95%CI: 0.73-0.91) with EpiScore, DRE, and atypical histological findings as most important contributors.

CONCLUSIONS

In men diagnosed with PCa, DNA-methylation profiling can detect under-sampled high-risk PCa in prostate biopsy specimens through a field effect. Predictive accuracy increased when EpiScore was combined with other clinical risk factors. These results suggest that EpiScore could aid in the detection of occult high-grade disease at the time of diagnosis, thereby improving the selection of candidates for Active Surveillance.

Targeting MicroRNAs in Prostate Cancer Radiotherapy

Radiotherapy is one of the most important treatment options for localized early-stage or advanced-stage prostate cancer (CaP). Radioresistance (relapse after radiotherapy) is a major challenge for the current radiotherapy. There is great interest in investigating mechanisms of radioresistance and developing novel treatment strategies to overcome radioresistance. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression at the post-transcriptional level, participating in numerous physiological and pathological processes including cancer invasion, progression, metastasis and therapeutic resistance. Emerging evidence indicates that miRNAs play a critical role in the modulation of key cellular pathways that mediate response to radiation, influencing the radiosensitivity of the cancer cells through interplaying with other biological processes such as cell cycle checkpoints, apoptosis, autophagy, epithelial-mesenchymal transition and cancer stem cells. Here, we summarize several important miRNAs in CaP radiation response and then discuss the regulation of the major signalling pathways and biological processes by miRNAs in CaP radiotherapy. Finally, we emphasize on microRNAs as potential predictive biomarkers and/or therapeutic targets to improve CaP radiosensitivity.

miRNAs as novel biomarkers in the management of prostate cancer

microRNAs (miRNAs) are small non-coding RNAs that control gene expression posttranscriptionally and are part of the giant non codifying genoma. Cumulating data suggest that miRNAs are promising potential biomarkers for many diseases, including cancer. Prostate cancer (PCa) detection is currently based in the serum prostate-specific antigen biomarker and digital rectal examination. However, these methods are limited by a low predictive value and the adverse consequences associated with overdiagnosis and overtreatment. New biomarkers that could be used for PCa detection and prognosis are still needed. Recent studies have demonstrated that aberrant expressions of microRNAs are associated with the underlying mechanisms of PCa. This review attempts to extensively summarize the current knowledge of miRNA expression patterns, as well as their targets and involvement in PCa pathogenesis. We focused our review in the value of circulating and urine miRNAs as biomarkers in PCa patients, highlighting the existing discrepancies between different studies, probably associated with the important methodological issues related to their quantitation and normalization. The majority of studies have been performed in serum or plasma, but urine obtained after prostate massage appears as a new way to explore the usefulness of miRNAs. Large screening studies to select a miRNA profile have been completed, but bioinformatics tools appear as a new approach to select miRNAs that are relevant in PCa development. Promising preliminary results were published concerning miR-141, miR-375 and miR-21, but larger and prospective studies using standardized methodology are necessary to define the value of miRNAs in the detection and prognosis of PCa.

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.

Human Prostate Tissue-derived Extracellular Matrix as a Model of Prostate Microenvironment

BACKGROUND

Clinical experience highlights the wide heterogeneity of primary prostate cancer (PPCa), even when potentially related to the same grade and stage. Currently available prediction tools and biomarkers do not always allow for early recognition of PPCa aggressive phenotype, sometimes making it impossible to distinguish among men harbouring indolent tumours or life-threatening disease.

OBJECTIVE

To establish a novel ex vivo/in vitro model suitable to estimate the invasive phenotype of PPCa cells (PPCaC).

DESIGN, SETTING, AND PARTICIPANTS

The ability of PPCaC to infiltrate the prostate extracellular matrix (ECM) was used as an index of invasion. ECM was obtained by decellularising 24 NT-prostate specimens from radical prostatectomy. PPCaC were obtained from six tumours with different Gleason patterns and pathological stages. Invasion ability was estimated in direct-cocolture experiments.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The extent of ECM invasion by PPCaC was quantified by counting the number of infiltrated cells. Mann-Whitney test was utilised for statistical comparisons.

RESULTS AND LIMITATIONS

Samples of ECM resulted to be free of cells and DNA and with a preserved three-dimensional structure and stromal protein content. The system resulted to be reliable since well characterised normal-, benign-, and malignant-prostate cell lines either re-epitheliased or invaded the matrices, according to their specific nature. Similarly, PPCaC invaded the ECMs consistently with their stage and biochemical recurrence. Of notice, this model was able to identify a different invasive phenotype even among tumours with equal Gleason patterns and pathological stages. The small sample size represents a limitation.

CONCLUSIONS

We developed an ex vivo/in vitro model able to reproduce the original PPCa-microenvironment and suitable to recognise the inherent invasive behaviour of PPCaC.

PATIENT SUMMARY

We developed a novel ex vivo/in vitro system which enables us to uncover which prostate tumours host potentially aggressive cancer cells. The identification of cancer cells with different invasive abilities will likely lead to the identification of new biomarkers to safely predict disease progression.

Pathological Outcome following Radical Prostatectomy in Men with Prostate Specific Antigen Greater than 10 ng/ml and Histologically Favorable Risk Prostate Cancer

PURPOSE

Active surveillance is now the treatment of choice in men with low risk prostate cancer. Although there is no consensus on which patients are eligible for active surveillance, prostate specific antigen above 10 ng/ml is generally excluded. In an attempt to determine the validity of using a prostate specific antigen cutoff of 10 ng/ml to counsel men considering active surveillance we analyzed a multi-institution database to determine the pathological outcome in men with prostate specific antigen greater than 10 ng/ml but histologically favorable risk prostate cancer.

MATERIALS AND METHODS

We queried a prospectively maintained database of men with histologically favorable risk prostate cancer who underwent radical prostatectomy between 2003 and 2015. The cohort was categorized into 3 groups based on prostate specific antigen level, including low-less than 10 ng/ml, intermediate-10 or greater to less than 20 and high-20 or greater. Associations of prostate specific antigen group with adverse pathological and oncologic outcomes were analyzed.

RESULTS

Of 2,125 patients 1,327 were categorized with histologically favorable risk disease. However on multivariate analyses the rates of up staging and upgrading were similar between the intermediate and low prostate specific antigen groups. In contrast compared to the intermediate prostate specific antigen group the high group had higher incidences of up staging (p = 0.02) and upgrading to 4 + 3 or greater disease (p = 0.046). Biochemical recurrence-free survival rates revealed no pairwise intergroup differences except between the low and high groups.

CONCLUSIONS

Patients with preoperatively elevated prostate specific antigen between 10 and less than 20 ng/ml who otherwise had histologically favorable risk prostate cancer were not at higher risk for adverse pathological outcomes than men with prostate specific antigen less than 10 ng/ml.

Identifying in vivo DCE MRI markers associated with microvessel architecture and gleason grades of prostate cancer

BACKGROUND

To identify computer extracted in vivo dynamic contrast enhanced (DCE) MRI markers associated with quantitative histomorphometric (QH) characteristics of microvessels and Gleason scores (GS) in prostate cancer.

METHODS

This study considered retrospective data from 23 biopsy confirmed prostate cancer patients who underwent 3 Tesla multiparametric MRI before radical prostatectomy (RP). Representative slices from RP specimens were stained with vascular marker CD31. Tumor extent was mapped from RP sections onto DCE MRI using nonlinear registration methods. Seventy-seven microvessel QH features and 18 DCE MRI kinetic features were extracted and evaluated for their ability to distinguish low from intermediate and high GS. The effect of temporal sampling on kinetic features was assessed and correlations between those robust to temporal resolution and microvessel features discriminative of GS were examined.

RESULTS

A total of 12 microvessel architectural features were discriminative of low and intermediate/high grade tumors with area under the receiver operating characteristic curve (AUC) > 0.7. These features were most highly correlated with mean washout gradient (WG) (max rho = -0.62). Independent analysis revealed WG to be moderately robust to temporal resolution (intraclass correlation coefficient [ICC] = 0.63) and WG variance, which was poorly correlated with microvessel features, to be predictive of low grade tumors (AUC = 0.77). Enhancement ratio was the most robust (ICC = 0.96) and discriminative (AUC = 0.78) kinetic feature but was moderately correlated with microvessel features (max rho = -0.52).

CONCLUSION

Computer extracted features of prostate DCE MRI appear to be correlated with microvessel architecture and may be discriminative of low versus intermediate and high GS.

Prediction of Significant Prostate Cancer at Prostate Biopsy and Per Core Detection Rate of Targeted and Systematic Biopsies Using Real-Time Shear Wave Elastography

Introduction: Prostate cancer (PCa) detection is accompanied by overdiagnosis and mischaracterization of PCa. Therefore, new imaging modalities like shear wave elastography (SWE) are required. Aim: The aim of this study was to evaluate per-core detection rates (DRs) of targeted biopsies and systematic biopsies and to test if SWE findings can predict presence of clinically significant PCa (csPCa) at biopsy. Patients and Methods: Overall, 95 patients scheduled for prostate biopsy in our center underwent SWE. SWE findings were classified into suspicious or normal. Targeted biopsies were taken in up to 3 SWE-suspicious areas. csPCa was defined as the presence of Gleason pattern ≥4, level of prostate-specific antigen ≥10 ng/ml or >2 positive cores. Results: Overall DR for csPCa in our study cohort was 40%. Per-core DR for exclusively SWE-targeted cores versus systematic samples cores was 10.5 vs. 8.6% (p = 0.3). In the logistic regression models, individuals with suspicious SWE findings are at 6.4-fold higher risk of harboring csPCa (p = 0.03). Gain in predictive accuracy was 2.3% (0.82 vs. 0.84, p = 0.01). Conclusions: Presence of suspicious SWE findings is an independent predictor of csPCa. Therefore, SWE may be helpful in selecting patients for biopsy. Nonetheless, per-core DR for SWE-targeted cores was not statistically significant higher than DR of systematic sampled cores. Therefore, additional systematic biopsy is mandatory.

Obligatory information that a patient diagnosed of prostate cancer and candidate for an active surveillance protocol must know

OBJECTIVES

To know the necessary information to reproduce the results found in the literature on active surveillance (AS) in prostate cancer (PCa) in our own center so that the information would be objective and correctly given to the patients. We have aimed to study the percentage of candidates for AS chosen in our setting, and the data on infrastaging, subgrading and prediction of insignificant PCa, debugging the predictive value of clinical variables to improve our selection criteria and finally to analyze the results of our patients enrolled in AS.

MATERIALS AND METHODS

A retro- and prospective review of our data bases was performed. A one-year period was analyzed to know AS candidates. Analysis of our radical prostatectomy specimens for infrastaging, subgrading and prediction of insignificant PCa (Epstein's criteria) was made as well as a uni/multivariate analysis of clinical variables in patients with insignificant PCa in the specimen. A prospective validation was performed with overall survival and survival free of active treatment (SFAT) as endpoints in patients enrolled in AS.

RESULTS

Between October-2010/October-2011, 44.7% of our PCa were candidates for AS, but only 11.2% choose it. The percentages found for infrastaging, subgrading and prediction of insignificant PCa were 14%, 31.4% and 55.7%, respectively. However, only just 6 patients (6.97%) had≥pT3a+Gleason≥7+volume>0.5cc PCa. The multivariate analysis showed that PSA density and number of affected cores were independent predictors of insignificant PCa. With a mean follow-up of 36±39months, 63 out of 232 patients enrolled in AS went on to active treatment (27.1%), with only 13 due to anxiety without pathologic progression. Median time of SFAT was 72.7 months (CI 95% 30.9-114.4). SFAT at 24 months was 76.4% (69.7-83.1%) and at 48 months 58.1% (48.8-67.4%). Only 10 patients died (4.3%), 9 due to causes different of PCa. Estimated overall survival at 5 years was 92.8% (CI 95% 86.7-98.9%).

CONCLUSIONS

It should be mandatory to have the exact knowledge of the local data of each Center in order to objectively inform patients about prostate biopsy efficiency, and if percentages of infrastaging, subgrading and prediction of insignificant PCa are in accordance with the literature. At 3 years, we reproduced the results of the longest series of AS, so we have ascertained that our AS protocol can be implemented with increasingly more patients.

Can we expand active surveillance criteria to include biopsy Gleason 3+4 prostate cancer? A multi-institutional study of 2,323 patients

OBJECTIVE

To test the expandability of active surveillance (AS) to Gleason score 3+4 cancers by assessing the unfavorable disease risk in a large multi-institutional cohort.

MATERIALS AND METHODS

We performed a retrospective analysis including 2,323 patients with localized Gleason score 3+4 prostate cancer who underwent a radical prostatectomy between 2005 and 2013 from 6 academic centers. We analyzed the rates of biopsy downgrading/upgrading and advanced stage in the overall cohort by employing standardized AS criteria (using biopsy Gleason score 3+4).

RESULTS

The final pathologic Gleason score was 3+3 = 6 in 8%, 3+4 = 7 in 67%, 4+3 = 7 in 20%, and 8 to 10 in 5% cases. The overall rate of unfavorable disease (upgrading or advanced stage or both) was 46%. In multivariable analysis, prostate-specific antigen (PSA) level>10 ng/ml, PSA density (PSAD) >0.15 ng/ml/g, clinical stage >T1, and>2 positive cores were predictors of unfavorable disease. According to the AS criteria used, the risk of unfavorable disease ranged from 30% to 42%. In patients without any risk factor (PSA level≤ 10 ng/ml, PSAD ≤ 0.15 ng/ml/g, T1c, and ≤ 2 positive cores), the unfavorable disease rate was 19%. The main limitations of this study are the retrospective design and nonstandardization of pathologic assessment between centers.

CONCLUSIONS

Approximately half of patients with biopsy Gleason score 3+4 cancer have unfavorable disease at final pathology. Nevertheless, expanding AS eligibility to these patients may be acceptable provided adherence to strict selection criteria leading to a<20% risk of unfavorable disease. Future tools for selection such as magnetic resonance imaging, early rebiopsy, and serum markers may be especially beneficial in this group of patients.

Expanded criteria to identify men eligible for active surveillance of low risk prostate cancer at Johns Hopkins: a preliminary analysis

PURPOSE

At our institution the eligibility criteria used to enroll patients in active surveillance are clinical stage T1, prostate specific antigen density less than 0.15 ng/ml, biopsy Gleason score 6 or less, 2 or fewer positive biopsy cores and 50% or less involvement of any biopsy core. We hypothesized that these criteria may be excessively strict, precluding many men from active surveillance.

MATERIALS AND METHODS

We studied pathological outcomes in men treated with radical prostatectomy between 1995 and 2012 who met 4 or more of the 5 active surveillance criteria. Outcomes included a definition of significant tumor (pathological Gleason 7 or greater, or nonorgan confined). We compared adverse pathology rates between men who met all 5 vs 4 of 5 active surveillance criteria.

RESULTS

Of 8,261 men 1,890 (22.9%) met all active surveillance eligibility criteria and 2,133 (25.8%) met 4. Men with values exceeding prostate specific antigen density and biopsy Gleason criteria were at increased risk for adverse pathological outcomes. Clinical stage greater than T1 was not associated with adverse pathological findings. The risk of significant tumors in men with clinical stage T2 lesions, 3 or fewer positive biopsy cores and less than 60% core involvement was comparable to that of men who met all active surveillance criteria.

CONCLUSIONS

Prostate specific antigen density greater than 0.15 ng/ml and biopsy Gleason score 7 or greater are strongly associated with adverse pathological findings at radical prostatectomy. Our findings suggest that active surveillance criteria should be expanded to include men with clinical stage T2 lesions and a greater number of positive biopsy cores of low grade. Based on these preliminary findings, we are in the process of reassessing active surveillance eligibility criteria using more detailed pathological analysis.