Comparison of Pathological and Oncologic Outcomes of Favorable Risk Gleason Score 3 + 4 and Low Risk Gleason Score 6 Prostate Cancer: Considerations for Active Surveillance

The role of PSMA PET/CT to predict upgrading in patients undergoing radical prostatectomy for ISUP grade group 1 prostate cancer

INTRODUCTION AND OBJECTIVES

To investigate the additive role of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) independent from multiparametric magnetic resonance imaging (mpMRI) and clinical-pathological parameters to predict pathological upgrading in patients with ISUP grade group (GG) 1 prostate cancer (PCa) at prostate biopsy.

MATERIALS AND METHODS

A total of 41 patients who underwent robotic radical prostatectomy (RP) for GG1 disease at prostate biopsy with preoperative PSMA PET/CT and mpMRI images available for central review were included in the study. Univariate and multivariate logistic regression analyses were performed to determine the independent predictors of pathological upgrading (GG ≥ 2).

RESULTS

Final RP pathology revealed upgrading in 26 patients (65.9%); to GG 2 disease in 25 cases and GG 4 disease in one case. International Society of Urological Pathology (ISUP) upgrading rates for prostate imaging-reporting and data system (PIRADS)-5, PIRADS-4, and PIRADS ≤ 3 lesions were 78%, 74%, and 38%, respectively. Fourteen out of 15 (93.3%) patients with an SUVmax ≥ 5.6 and all patients with an SUVmax ≥ 6.5 (n = 10) had pathological upgrading. The upgrading rate in patients with SUV < 5.6 was 46.2% (12/26). Intraprostatic SUVmax ≥ 5.6 was found as the only independent predictor of pathological upgrading in multivariate analysis.

CONCLUSION

High prostatic PSMA uptake was found to be a very reliable predictor of pathological upgrading, but low PSMA uptake cannot exclude pathological upgrading. Intraprostatic PSMA uptake along with previously known mpMRI and biopsy-related parameters should be considered when making a treatment decision in patients with GG1 PCa at prostate biopsy.

Intermediate-risk Prostate Cancer-A Sheep in Wolf's Clothing?

This case-based discussion describes a 65-year-old man newly diagnosed with International Society of Urological Pathology (ISUP) grade 2 prostate cancer (PCa). According to the European Association of Urology classification system, the patient harbors an intermediate-risk cancer. In step-by step discussion, we elaborate guideline-based treatment modalities for intermediate-risk PCa focused on debating active surveillance versus active treatment. Thereby, we discuss the importance of patient characteristics, including age, hereditary factors, life expectancy and comorbidity status, findings of multiparametric magnetic resonance imaging, as well as prostate-specific antigen (PSA) density and PSA kinetics, in predicting the clinical course of the disease. In addition, we focus on cribriform pathology as a predictor of adverse outcomes and critically discuss its relevance in patient management. Lastly, we outline genomic stratification in ISUP 2 cancer as a future tool to predict PCa aggressiveness. PATIENT SUMMARY: Based on current guidelines, patients with intermediate-risk prostate cancer are treated actively or can alternatively undergo an active surveillance approach when favorable risk factors are present. One major issue is to discriminate between patients who benefit from an active therapy approach and those who benefit from a deferred treatment. Therefore, reliable biomarkers and early predictors of disease progression are needed urgently.

Active surveillance in favorable intermediate risk prostate cancer: outstanding questions and controversies

PURPOSE OF REVIEW

Active surveillance has become the preferred management strategy for patients with low risk prostate cancer, but it is unclear if active surveillance can be safely extended to favorable intermediate risk (FIR) prostate cancer patients. Furthermore, defining a favorable intermediate risk prostate cancer population safe for active surveillance remains elusive due to paucity of high-level data in this population. This article serves to review relevant data, particularly the safety of active surveillance in grade group 2 patients, and what tools are available to aid in selecting a favorable subset of intermediate risk patients.

RECENT FINDINGS

Active surveillance studies with long-term data appear to report worsened survival outcomes in intermediate risk patients when compared to those undergoing definitive treatment, but there exists a subset of intermediate risk patients with nearly equivalent outcomes to low risk patients on active surveillance. Tools such as percentage and total length of Gleason pattern 4, tumor volume, prostate specific antigen density, magnetic resonance imaging, and genomic modifiers may help to select a favorable subset of intermediate risk prostate cancer appropriate for active surveillance.

SUMMARY

Active surveillance is a viable strategy in select patients with low volume group grade 2 (GG2) prostate cancer. Prospective and retrospective data in the FIR population appear to be mostly favorable in regards to survival outcomes, but there exists some heterogeneity with respect to long-term outcomes in this patient population.

Machine Learning-Based Prediction of Pathological Upgrade From Combined Transperineal Systematic and MRI-Targeted Prostate Biopsy to Final Pathology: A Multicenter Retrospective Study

Objective

This study aimed to evaluate the pathological concordance from combined systematic and MRI-targeted prostate biopsy to final pathology and to verify the effectiveness of a machine learning-based model with targeted biopsy (TB) features in predicting pathological upgrade.

Materials and Methods

All patients in this study underwent prostate multiparametric MRI (mpMRI), transperineal systematic plus transperineal targeted prostate biopsy under local anesthesia, and robot-assisted laparoscopic radical prostatectomy (RARP) for prostate cancer (PCa) sequentially from October 2016 to February 2020 in two referral centers. For cores with cancer, grade group (GG) and Gleason score were determined by using the 2014 International Society of Urological Pathology (ISUP) guidelines. Four supervised machine learning methods were employed, including two base classifiers and two ensemble learning-based classifiers. In all classifiers, the training set was 395 of 565 (70%) patients, and the test set was the remaining 170 patients. The prediction performance of each model was evaluated by area under the receiver operating characteristic curve (AUC). The Gini index was used to evaluate the importance of all features and to figure out the most contributed features. A nomogram was established to visually predict the risk of upgrading. Predicted probability was a prevalence rate calculated by a proposed nomogram.

Results

A total of 515 patients were included in our cohort. The combined biopsy had a better concordance of postoperative histopathology than a systematic biopsy (SB) only (48.15% vs. 40.19%, p = 0.012). The combined biopsy could significantly reduce the upgrading rate of postoperative pathology, in comparison to SB only (23.30% vs. 39.61%, p < 0.0001) or TB only (23.30% vs. 40.19%, p < 0.0001). The most common pathological upgrade occurred in ISUP GG1 and GG2, accounting for 53.28% and 20.42%, respectively. All machine learning methods had satisfactory predictive efficacy. The overall accuracy was 0.703, 0.768, 0.794, and 0.761 for logistic regression, random forest, eXtreme Gradient Boosting, and support vector machine, respectively. TB-related features were among the most contributed features of a prediction model for upgrade prediction.

Conclusion

The combined effect of SB plus TB led to a better pathological concordance rate and less upgrading from biopsy to RP. Machine learning models with features of TB to predict PCa GG upgrading have a satisfactory predictive efficacy.

Metastasis and Mortality in Men With Low- and Intermediate-Risk Prostate Cancer on Active Surveillance

BACKGROUND

Active surveillance (AS) is a safe treatment option for men with low-risk, localized prostate cancer. However, the safety of AS for patients with intermediate-risk prostate cancer remains unclear.

PATIENTS AND METHODS

We identified men with NCCN-classified low-risk and favorable and unfavorable intermediate-risk prostate cancer diagnosed between 2001 and 2015 and initially managed with AS in the Veterans Health Administration. We analyzed progression to definitive treatment, metastasis, prostate cancer-specific mortality (PCSM), and all-cause mortality using cumulative incidences and multivariable competing-risks regression.

RESULTS

The cohort included 9,733 men, of whom 1,007 (10.3%) had intermediate-risk disease (773 [76.8%] favorable, 234 [23.2%] unfavorable), followed for a median of 7.6 years. The 10-year cumulative incidence of metastasis was significantly higher for patients with favorable (9.6%; 95% CI, 7.1%-12.5%; P<.001) and unfavorable intermediate-risk disease (19.2%; 95% CI, 13.4%-25.9%; P<.001) than for those with low-risk disease (1.5%; 95% CI, 1.2%-1.9%). The 10-year cumulative incidence of PCSM was also significantly higher for patients with favorable (3.7%; 95% CI, 2.3%-5.7%; P<.001) and unfavorable intermediate-risk disease (11.8%; 95% CI, 6.8%-18.4%; P<.001) than for those with low-risk disease (1.1%; 95% CI, 0.8%-1.4%). In multivariable competing-risks regression, favorable and unfavorable intermediate-risk patients had significantly increased risks of metastasis and PCSM compared with low-risk patients (all P<.001).

CONCLUSIONS

Compared with low-risk patients, those with favorable and unfavorable intermediate-risk prostate cancer managed with AS are at increased risk of metastasis and PCSM. AS may be an appropriate option for carefully selected patients with favorable intermediate-risk prostate cancer, though identification of appropriate candidates and AS protocols should be tested in future prospective studies.

Biorepositories and Databanks for the Development of Novel Biomarkers for Genitourinary Cancer Prevention and Management

CONTEXT

Translational research in uro-oncology depends on the availability of high-quality biospecimens and associated data to advance precision medicine and improve clinical outcomes. Procurement, storage, and annotation of these specimens represent critical steps towards this end.

OBJECTIVE

To review best-practice experiences gained via the McCain GU BioBank, a repository of more than 750 000 biospecimens obtained from more than 16 000 patients attending clinics at the University Health Network in Toronto, Canada.

EVIDENCE ACQUISITION

The review summarizes our experiences at a large single-institution genitourinary oncology biorepository.

EVIDENCE SYNTHESIS

Key findings are placed in the context of emerging trends in genitourinary oncology, with a focus on integration of molecular profiling and clinical data with traditional biorepository management. Proposed approaches provide high-quality biospecimens with comprehensive and reliable clinical data that can fuel innovation and discovery in research.

CONCLUSIONS

Biorepositories are vital for improving clinical outcomes and advancing personalized medicine. High-quality biospecimens and their associated clinical data are crucial for validation of biomarkers in oncology. Efforts to procure, store, and annotate clinical specimens represent critical steps in translational research. Elements such as biobank size, biospecimen types, disease cohorts, predetermined collection protocols, broad informed consent, sample handling and storage protocols, and available infrastructure directly influence the effectiveness and capacity of a biobank.

PATIENT SUMMARY

Biorepositories, or biobanks, are facilities that store biospecimens such as blood, urine, or tissue (usually collected from humans) for use in research. Biobanks have become an important resource in medical research, as they provide high-quality specimens to support different types of contemporary research such as genomics, biomarker discovery, and personalized medicine. Clinical management and treatment of genitourinary cancers, such as prostate, kidney, and bladder cancers, are particularly suited for biomarker research. The provision of biospecimens and their associated clinical data have become crucial for validation of biomarkers in these cancers.

Radical prostatectomy for localized prostate cancer: 20-year oncological outcomes from a German high-volume center

INTRODUCTION

Long-term outcomes of prostate cancer (CaP) patients treated with radical prostatectomy (RP) from European cohorts are under-reported. We report on 22,843 RP patients from the Martini-Klinik Prostate Cancer Centre treated between 1992 and 2017.

PATIENTS AND METHODS

Biochemical recurrence (BCR) free survival, metastasis free survival (MFS), and cancer specific survival (CSS) were stratified according to National Comprehensive Cancer Network (NCCN) risk categories, pT, and pN stages, RP Gleason Grade Groups (GGG), and surgical margin status (R0/R1). For time to event analyses, uni- and multivariable Cox's proportional hazards models and univariable Kaplan-Meier analyses were applied.

RESULTS

Median follow up was 68 months. Most favourable 20-year survival rates were exhibited in NCCN low risk (78.7% BCR-free, 96.8% MFS, 90.1% CSS) and pT2, GGG 1 to 2, R0 patients (83.1% BCR-free, 96.7% MFS, 92.6% CSS). 20-year follow up was not constantly reached in patients with aggressive CaP features. For example, NCCN very high-risk patients exhibited 15-year BCR-free survival of 30.5%, while 20-year MFS and CSS in these individuals was reached (64.1% and 60.8%, respectively). Lowest 10-year BCR-free survival (35.6%) was exhibited in pT3b, GGG 4 to 5, R0. Lowest 10-year MFS (49.5%) was exhibited in pT2, GGG 4 to 5, R1. Lowest 10-year CSS (69.8%) was exhibited in pT3b, GGG 4 to 5, R1 patients. In separate pN1 analyses, lowest 10-year BCR-free survival (14.5%), MFS (56.9%), and CSS (71.9%) were exhibited in patients with 3 or more positive lymph nodes.

CONCLUSION

Oncological outcomes after RP can be excellent for individuals with favorable CaP characteristics, also after 20 years of follow up.

Selecting Patients with Favorable Risk, Grade Group 2 Prostate Cancer for Active Surveillance-Does Magnetic Resonance Imaging Have a Role?

PURPOSE

The National Comprehensive Cancer Network® recommends that selected men with grade group 2 prostate cancer be considered for active surveillance. However, selecting which patients with grade group 2 disease can be safely managed by active surveillance remains controversial. The aim of this study was to evaluate the association of multiparametric magnetic resonance imaging with adverse pathology in the radical prostatectomy specimen of men with favorable risk grade group 2 prostate cancer, which could help select patients for active surveillance.

MATERIALS AND METHODS

We retrospectively analyzed a cohort of patients with favorable grade group 2 disease who underwent radical prostatectomy between 2010 and 2019. Preoperative multiparametric magnetic resonance imaging was scored as negative (no identifiable lesion), positive (identifiable lesion) or equivocal. We defined a multivariable logistic regression model with multiparametric magnetic resonance imaging score as the predictor and adverse pathology (up staging to T3a/b disease, upgrading to ≥grade group 3 or lymph node invasion) as the outcome, adjusting for preoperative prostate specific antigen, biopsy Gleason grade, clinical stage, and number of negative and positive prostate biopsy cores. Secondary outcomes of biochemical recurrence, grade group upgrading alone and the added value of incorporating multiparametric magnetic resonance imaging data into the nomogram were also investigated.

RESULTS

We identified 1,117 patients with favorable risk grade group 2 disease who underwent radical prostatectomy. Positive multiparametric magnetic resonance imaging was associated with higher rates of adverse pathology (OR 2.55, 95% CI 1.75-3.40, p <0.0001) and upgrading (OR 3.89, 95% CI 2.00-7.56, p <0.0001). However, as our study included only grade group 2 patients who underwent radical prostatectomy, our cohort may represent a higher risk group than grade group 2 patients as a whole. Adding multiparametric magnetic resonance imaging results to a standard prediction model led to higher net benefit on decision curve analysis. An identifiable lesion on multiparametric magnetic resonance imaging was associated with an increased risk of aggressive pathological features in the radical prostatectomy specimen of patients with favorable risk grade group 2 prostate cancer who were potential active surveillance candidates. This information could be used to inform biopsy strategy, counsel patients on treatment options and guide strategies for those on active surveillance.

CONCLUSIONS

Combining multiple magnetic resonance imaging modalities (multiparametric magnetic resonance imaging) provides a more accurate prediction of the risk presented by prostate cancer than current prediction methods. In this study, positive magnetic resonance imaging results approximately doubled the chances that a patient with favorable risk prostate cancer would be found to have adverse pathology when their prostate was removed. Thus, multiparametric magnetic resonance imaging could help select patients with favorable risk cancer who may be good candidates for active surveillance, and help guide biopsy and surveillance strategies for such patients.

Clinical outcome comparison of Grade Group 1 and Grade Group 2 prostate cancer with and without cribriform architecture at the time of radical prostatectomy

Aims

Invasive cribriform and intraductal carcinoma are associated with aggressive disease in Grade Group 2 (GG2) prostate cancer patients. However, the characteristics and clinical outcome of patients with GG2 prostate cancer without cribriform architecture (GG2−) as compared with those with Grade Group 1 (GG1) prostate cancer are unknown. The aim of this study was to investigate the clinical and pathological characteristics of GG1 and GG2− prostate cancer in radical prostatectomy specimens.

Methods and results

We reviewed 835 radical prostatectomy specimens for Grade Group, pT stage, surgical margin status, and the presence of cribriform architecture. Biochemical recurrence‐free survival and metastasis were used as clinical outcomes. GG1 prostate cancer was seen in 207 patients, and GG2 prostate cancer was seen in 420 patients, of whom 228 (54%) showed cribriform architecture (GG2+) and 192 (46%) did not. GG2− patients had higher prostate‐specific antigen levels (9.4 ng/ml versus 7.0 ng/ml; P < 0.001), more often had extraprostatic extension (36% versus 11%; P < 0.001) and had more positive surgical margins (27% versus 17%; P = 0.01) than GG1 patients. GG2− patients had shorter biochemical recurrence‐free survival (hazard ratio 2.7, 95% confidence interval 1.4–4.9; P = 0.002) than GG1 patients. Lymph node and distant metastasis were observed neither in GG2− nor in GG1 patients, but occurred in 22 of 228 (10%) GG2+ patients.

Conclusion

In conclusion, patients with GG2− prostate cancer at radical prostatectomy have more advanced disease and shorter biochemical recurrence‐free survival than those with GG1 prostate cancer, but both groups have a very low risk of developing metastasis.

Prediction of Pathological Upgrading at Radical Prostatectomy in Prostate Cancer Eligible for Active Surveillance: A Texture Features and Machine Learning-Based Analysis of Apparent Diffusion Coefficient Maps

Objective

To evaluate a combination of texture features and machine learning-based analysis of apparent diffusion coefficient (ADC) maps for the prediction of Grade Group (GG) upgrading in Gleason score (GS) ≤6 prostate cancer (PCa) (GG1) and GS 3 + 4 PCa (GG2).

Materials and methods

Fifty-nine patients who were biopsy-proven to have GG1 or GG2 and underwent MRI examination with the same MRI scanner prior to transrectal ultrasound (TRUS)-guided systemic biopsy were included. All these patients received radical prostatectomy to confirm the final GG. Patients were divided into training cohort and test cohort. 94 texture features were extracted from ADC maps for each patient. The independent sample t-test or Mann−Whitney U test was used to identify the texture features with statistically significant differences between GG upgrading group and GG non-upgrading group. Texture features of GG1 and GG2 were compared based on the final pathology of radical prostatectomy. We used the least absolute shrinkage and selection operator (LASSO) algorithm to filter features. Four supervised machine learning methods were employed. The prediction performance of each model was evaluated by area under the receiver operating characteristic curve (AUC). The statistical comparison between AUCs was performed.

Results

Six texture features were selected for the machine learning models building. These texture features were significantly different between GG upgrading group and GG non-upgrading group (P < 0.05). The six features had no significant difference between GG1 and GG2 based on the final pathology of radical prostatectomy. All machine learning methods had satisfactory predictive efficacy. The diagnostic performance of nearest neighbor algorithm (NNA) and support vector machine (SVM) was better than random forests (RF) in the training cohort. The AUC, sensitivity, and specificity of NNA were 0.872 (95% CI: 0.750−0.994), 0.967, and 0.778, respectively. The AUC, sensitivity, and specificity of SVM were 0.861 (95%CI: 0.732−0.991), 1.000, and 0.722, respectively. There had no significant difference between AUCs in the test cohort.

Conclusion

A combination of texture features and machine learning-based analysis of ADC maps could predict PCa GG upgrading from biopsy to radical prostatectomy non-invasively with satisfactory predictive efficacy.

Cause-specific mortality of low and selective intermediate-risk prostate cancer patients with active surveillance or watchful waiting

Background

Active surveillance or watchful waiting (AS/WW) is increasingly being used as an alternative strategy to radical prostatectomy or radiation therapy for appropriately selected patients with prostate cancer (PCa). However, the prognosis of low-risk and selective intermediate-risk PCa patients after AS/WW is poorly defined. In this study we reviewed the patients registered in the Surveillance, Epidemiology, and End Results (SEER) Program to establish a competing risk nomogram for the prediction of prostate cancer-specific mortality (PCSM).

Methods

The information of patients undergoing AS/WW in the SEER program from 2004 to 2015 was obtained. All patients were ISUP (International Society of Urological Pathology) grade 1 or 2 PCa and also fulfilled the National Comprehensive Cancer Network’s definition of low-risk PCa [prostate specific antigen (PSA) <10 ng/mL and cT2aN0M0 or less)]. A competing risk nomogram was used to analyze the association of tumor characteristics with PCSM and non-PCSM among the PCa patients with AS/WW. All cases were randomly divided into a training cohort and a validation cohort (1:1). A competing risk nomogram was constructed to predict PCSM in PCa patients with AS/WW. The performance of the PCSM nomogram was evaluated using the concordance index (C-index) and calibration curve.

Results

A total of 30,538 PCa patients were identified as low risk or selective intermediate risk with AS/WW. The 10-year cumulative incidence of death from prostate cancer and death from other cause were 2.8% (95% CI: 2.4–3.1%) and 19.3% (95% CI: 17.8–20.5%), respectively. Variables associated with PCSM included age, marital status, PSA, and ISUP grade. The PCSM nomogram had a good performance in both the training and validation cohorts, with a C-index of 0.744 (95% CI: 0.700–0.781, P<0.001) and 0.738 (95% CI: 0.700–0.777, P<0.001), respectively.

Conclusions

Overall, the prognosis was favorable for the low- and selective intermediate-risk PCa patients with AS/WW. The competing risk nomogram yielded a good performance in identifying subgroups of patients with a higher risk of PCSM and potential candidates for AS/WW.

No detrimental effect of a positive family history on postoperative upgrading and upstaging in men with low risk and favourable intermediate-risk prostate cancer: implications for active surveillance

Purpose

To assess whether a first-degree family history or a fatal family history of prostate cancer (PCa) are associated with postoperative upgrading and upstaging among men with low risk and favourable intermediate-risk (FIR) PCa and to provide guidance on clinical decision making for active surveillance (AS) in this patient population.

Methods

Participants in the German Familial Prostate Cancer database diagnosed from 1994 to 2019 with (1) low risk (clinical T1c–T2a, biopsy Gleason Grade Group (GGG) 1, PSA < 10 ng/ml), (2) Gleason 6 FIR (clinical T1c–T2a, GGG 1, PSA 10–20 ng/ml), and (3) Gleason 3 + 4 FIR (clinical T1c–T2a, GGG 2, PSA < 10 ng/ml) PCa who were subsequently treated with radical prostatectomy (RP) were analysed for upgrading, defined as postoperative GGG 3 tumour or upstaging, defined as pT3–pT4 or pN1 disease at RP. Logistic regression analysis was used to assess whether PCa family history was associated with postoperative upgrading or upstaging.

Results

Among 4091 men who underwent RP, mean age at surgery was 64.4 (SD 6.7) years, 24.7% reported a family history, and 3.4% a fatal family history. Neither family history nor fatal family history were associated with upgrading or upstaging at low risk, Gleason 6 FIR, and Gleason 3 + 4 FIR PCa patients.

Conclusion

Results from the current study indicated no detrimental effect of family history on postoperative upgrading or upstaging. Therefore, a positive family history or fatal family history of PCa in FIR PCa patients should not be a reason to refrain from AS in men otherwise suitable.

Electronic supplementary material

The online version of this article (10.1007/s00345-020-03485-5) contains supplementary material, which is available to authorized users.

Clinicopathological characteristics of glomeruloid architecture in prostate cancer

Glomeruloid architecture is the least common Gleason 4 growth pattern in prostate adenocarcinoma. Its clinicopathological features and relation with cribriform architecture, which has been recognized as an adverse feature, remains to be established. Our objective was to investigate clinicopathological features of glomeruloid architecture in radical prostatectomies. We reviewed 1064 radical prostatectomy specimens and recorded Grade Group, pT-stage, margin status, Gleason pattern percentages, and growth patterns. Simple and complex glomerulations were distinguished by gland size and intraluminal cribriform protrusions. Clinical endpoint was biochemical recurrence-free survival. Glomerulations were identified in 365 (34%) specimens. In 472 Grade Group 2 patients, 210 (44%) had simple and 92 (19%) complex glomerulations. Complex glomerulations coincided with cribriform architecture more often than simple glomerulations (67% versus 52%; P = 0.01). Men with simple glomerulations had significantly lower prostate specific antigen (PSA) levels (9.7 versus 12.1 ng/ml; P = 0.03), percentage Gleason pattern 4 (19% versus 25%; P = 0.001), extra-prostatic extension (34% versus 50%; P = 0.01), and positive surgical margins (25% versus 39%; P = 0.04) than those with cribriform architecture. Extra-prostatic extension (37%) and positive surgical margins (30%) in men with complex glomerulations resembled those with simple glomeruloid rather than those with cribriform architecture. In multivariate Cox regression analysis adjusted for PSA, pT-stage, margin status, and lymph node metastases, cribriform architecture had independent predictive value for biochemical recurrence-free survival (hazard ratio (HR)) 1.9; 95% confidence interval (CI) 1.2-2.9; P = 0.004), while simple (HR 0.8; 95% CI 0.5-1.2; P = 0.26) and complex (HR 0.9; 95% CI 0.5-1.6; P = 0.67) glomerulations did not. Both simple and complex glomeruloid architecture are associated with better outcome than cribriform architecture in Grade Group 2 prostate cancer patients. Therefore, glomeruloid pattern and particularly complex glomerulations should not be classified as a cribriform growth pattern variant in radical prostatectomy specimens.

A 10-gene signature as a predictor of biochemical recurrence after radical prostatectomy in patients with prostate cancer and a Gleason score ≥7

The time and speed of biochemical recurrence (BCR) of prostate cancer (PCa) after radical prostatectomy (RP) is highly variable. Stratification methods based on TNM staging and Gleason score (GS) do not allow the identification of patients at risk of BCR following RP. Therefore, the aim of the present study was to identify molecular signatures that can predict BCR risk effectively and facilitate treatment-related decisions for patients with PCa. RNA sequencing data and corresponding clinical data were downloaded from The Cancer Genome Atlas (TCGA) and Oncomine databases. Bioinformatics analysis was performed to identify differentially expressed genes in patients with GS=6 and GS ≥7. Cox regression models were used to determine the PCa signature (PCasig) and a clinical nomogram for the prediction of BCR. The performance of nomograms was assessed using time-dependent receiver operating characteristic curves and the concordance index (C-index). A PCasig comprising 10 genes, including SEMG2, KCNJ16, TFAP2B, SYCE1, KCNU1, AFP, GUCY1B2, GRIA4, NXPH1 and SOX11, was significantly associated with BCR, which was identified in TCGA cohort [hazard ratio (HR), 5.18; 95% CI, 3.241-8.272; C-index, 0.777] and validated in the Oncomine cohort (HR, 2.78; 95% CI, 1.39-5.54; C-index, 0.66). The expression levels of SEMG2, KCNJ16 and TFAP2B were downregulated in patients with GS ≥7. The expression levels of SYCE1, KCNU1, AFP, GUCY1B2, GRIA4, NXPH1 and SOX11 were upregulated in patients with GS ≥7. The clinical nomogram was constructed based on the GS and pathologic T stage (HR, 4.15; 95% CI, 1.39-5.54; C-index, 0.713). The addition of the PCasig to the clinical nomogram significantly improved prognostic value (HR, 7.25; 95% CI, 4.54-11.56; C-index, 0.782) with an net reclassification improvement of 75.3% (95% CI, 46.8-104.6%). Furthermore, the endogenous expression of each gene in the PCasig was measured in five PCa cell lines and in normal prostate cells, and these genes exhibited different expression levels relative to one another. In conclusion, an PCasig was identified by mining TCGA and successfully validated in an Oncomine cohort. This PCasig was an independent prognostic factor with a greater prognostic value for all patients regardless of GS than traditional clinical variables, which can improve the performance of clinical nomograms in predicting BCR of patients with GS ≥7.

MEIS-mediated suppression of human prostate cancer growth and metastasis through HOXB13-dependent regulation of proteoglycans

The molecular roles of HOX transcriptional activity in human prostate epithelial cells remain unclear, impeding the implementation of new treatment strategies for cancer prevention and therapy. MEIS proteins are transcription factors that bind and direct HOX protein activity. MEIS proteins are putative tumor suppressors that are frequently silenced in aggressive forms of prostate cancer. Here we show that MEIS1 expression is sufficient to decrease proliferation and metastasis of prostate cancer cells in vitro and in vivo murine xenograft models. HOXB13 deletion demonstrates that the tumor-suppressive activity of MEIS1 is dependent on HOXB13. Integration of ChIP-seq and RNA-seq data revealed direct and HOXB13-dependent regulation of proteoglycans including decorin (DCN) as a mechanism of MEIS1-driven tumor suppression. These results define and underscore the importance of MEIS1-HOXB13 transcriptional regulation in suppressing prostate cancer progression and provide a mechanistic framework for the investigation of HOXB13 mutants and oncogenic cofactors when MEIS1/2 are silenced.

The long-term outcomes of Gleason grade groups 2 and 3 prostate cancer managed by active surveillance: Results from a large, population-based cohort

INTRODUCTION

Active surveillance (AS) is an accepted management strategy for low-risk prostate cancer (PCa), but its role in the management of favorable intermediate-risk PCa remains controversial. Most reports studying the role of AS for these men generally lack long-term followup and include small numbers of patients. Our objective was to report the outcomes of men diagnosed with Gleason grade groups (GGG) 2 and 3 PCa who were managed expectantly.

METHODS

Using administrative datasets and pathology reports, we identified all men who were diagnosed with GGG 2 and 3 PCa and managed expectantly between 2002 and 2011 in Ontario, Canada. Outcomes and associated factors were estimated using cumulative incidence function methods and multivariable Cox regression models, respectively.

RESULTS

We identified 926 men who were managed expectantly (AS [n=374] or watchful waiting [n=552]). The eight-year cancer-specific survival was 94% and 89% for the AS and watchful waiting cohorts, respectively. Among AS men, 266 (71%) received treatment after a followup of approximately eight years. Cumulative AS discontinuation rates at one and five years were 30.5% and 65.1%, respectively.

CONCLUSIONS

Expectant management of GGG 2 and 3 PCa may be an option for certain men. Notably for AS patients, the cancer-specific mortality at eight years was 6%, and over 65% of men underwent treatment within five years. Further studies are required to evaluate which patients, based on disease-specific features and competing health risks, would benefit most from a conservative strategy.

Patients with Biopsy Gleason Score 3 + 4 Are Not Appropriate Candidates for Active Surveillance

OBJECTIVE

The aim of this study was to evaluate the feasibility of including patients with biopsy Gleason score (bGS) 3 + 4 prostate cancer in an active surveillance (AS) protocol.

METHODS

A total of 615 patients underwent a radical prostatectomy and satisfied the following requirements: prostate-specific antigen ≤10 ng/dL, clinical stage T1c or T2a, 2 or fewer positive biopsy cores, and bGS 6 or 3 + 4 prostate cancer. The patients were divided into two groups according to their bGS (bGS 6 group, n =534; bGS 3 + 4 group, n = 81).

RESULTS

The adverse pathological features were significantly higher in the bGS 3 + 4 group (16.7 vs. 49.4%, p< 0.001). Biochemical recurrence (BCR)-free survival was also significantly lower in this group (p < 0.001). In a multivariate analysis, clinical stage (odds ratio [OR] 2.026, p =0.007), maximum percentage of biopsy core involvement (OR 1.015, p = 0.014), and bGS (OR 1.913, p = 0.030) were independent risk factors for adverse pathological features. However, the bGS was the only variable to forecast BCR (hazard ratio 3.567, p < 0.001).

CONCLUSIONS

A bGS 3 + 4 was the leading risk factor for a worse postoperative prognosis. Therefore, patients with a bGS 3 + 4 are not appropriate candidates for AS.

Can SUVmax values of Ga-68-PSMA PET/CT scan predict the clinically significant prostate cancer?

PURPOSE

The intensity of prostate-specific membrane antigen (PSMA) expression increases as the tumor grade increases and the uptake of Ga-68-PSMA is higher in high-grade tumors. The aim of the present study was to evaluate the correlation of preoperative tracer uptake of primary tumor to Gleason Score in patients who underwent prostatectomy.

PATIENTS AND METHODS

We retrospectively evaluated 141 patients who had Ga-68-PSMA positron emission tomography/computed tomography (PET/CT) imaging and who underwent prostatectomy. All patients had a diagnosis of prostate cancer on the basis of 10-24 cores transrectal ultrasound-guided biopsy (TRUS-Bx). Histological assessment was performed according to the New Contemporary Prostate Cancer Grading System. All patients had a prostate-specific antigen (PSA) level measurement within maximum of 28 days before Ga-68-PSMA PET/CT. Region of interests were drawn manually around the prostate gland, avoiding the bladder activity, to calculate the maximum standardized uptake values (SUVmax) values.

RESULTS

The median PSA values for all patients were 10.0 ng/ml. PSA values for low-risk patients were significantly lower than those of high-risk patients (P<0.001). There were 41.1% upgrades and 7.8% downgrades following prostatectomy in terms of Grade Groups. According to the final pathology reports, 21% (n=16) of patients moved from a low-risk level (grade groups 1+2) to a high-risk level (grade groups 3+4+5). The median SUVmax value was 8.8, ranging from 2.1 to 62.4. There was a strong correlation between SUVmax values and grade groups (Pearson ρ=0.66) (P<0.001). The mean SUVmax values of high-risk patients were significantly higher than those of low-risk patients (18.9±12.1 vs. 7.16±6.2, respectively) (P<0.001). Receiver operation characteristic curve analysis of SUVmax at the cut-off value of 9.1 showed a high sensitivity (78%) and specificity (81%) for detection of high risk disease.

CONCLUSION

SUVmax values correlate significantly with the grade groups of the primary tumor. The intraprostatic accumulation sites may predict clinically significant cancer and potentially serve as a target for biopsy sampling in conjunction with mpMRI in selected patients.

Validation of the Decipher Test for predicting adverse pathology in candidates for prostate cancer active surveillance

Background

Many men diagnosed with prostate cancer are active surveillance (AS) candidates. However, AS may be associated with increased risk of disease progression and metastasis due to delayed therapy. Genomic classifiers, e.g., Decipher, may allow better risk-stratify newly diagnosed prostate cancers for AS.

Methods

Decipher was initially assessed in a prospective cohort of prostatectomies to explore the correlation with clinically meaningful biologic characteristics and then assessed in diagnostic biopsies from a retrospective multicenter cohort of 266 men with National Comprehensive Cancer Network (NCCN) very low/low and favorable-intermediate risk prostate cancer. Decipher and Cancer of the Prostate Risk Assessment (CAPRA) were compared as predictors of adverse pathology (AP) for which there is universal agreement that patients with long life-expectancy are not suitable candidates for AS (primary pattern 4 or 5, advanced local stage [pT3b or greater] or lymph node involvement).

Results

Decipher from prostatectomies was significantly associated with adverse pathologic features (p-values < 0.001). Decipher from the 266 diagnostic biopsies (64.7% NCCN-very-low/low and 35.3% favorable-intermediate) was an independent predictor of AP (odds ratio 1.29 per 10% increase, 95% confidence interval [CI] 1.03–1.61, p-value 0.025) when adjusting for CAPRA. CAPRA area under curve (AUC) was 0.57, (95% CI 0.47–0.68). Adding Decipher to CAPRA increased the AUC to 0.65 (95% CI 0.58–0.70). NPV, which determines the degree of confidence in the absence of AP for patients, was 91% (95% CI 87–94%) and 96% (95% CI 90–99%) for Decipher thresholds of 0.45 and 0.2, respectively. Using a threshold of 0.2, Decipher was a significant predictor of AP when adjusting for CAPRA (p-value 0.016).

Conclusion

Decipher can be applied to prostate biopsies from NCCN-very-low/low and favorable-intermediate risk patients to predict absence of adverse pathologic features. These patients are predicted to be good candidates for active surveillance.