Reliability of whole mount radical prostatectomy histopathology as the ground truth for artificial intelligence assisted prostate imaging.

The development of artificial intelligence-based imaging techniques for prostate cancer (PCa) detection and diagnosis requires a reliable ground truth, which is generally based on histopathology from radical prostatectomy specimens. This study proposes a comprehensive protocol for the annotation of prostatectomy pathology slides. To evaluate the reliability of the protocol, interobserver variability was assessed between five pathologists, who annotated ten radical prostatectomy specimens consisting of 74 whole mount pathology slides. Interobserver variability was assessed for both the localization and grading of PCa. The results indicate excellent overall agreement on the localization of PCa (Gleason pattern ≥ 3) and clinically significant PCa (Gleason pattern ≥ 4), with Dice similarity coefficients (DSC) of 0.91 and 0.88, respectively. On a per-slide level, agreement for primary and secondary Gleason pattern was almost perfect and substantial, with Fleiss Kappa of .819 (95% CI .659-.980) and .726 (95% CI .573-.878), respectively. Agreement on International Society of Urological Pathology Grade Group was evaluated for the index lesions and showed agreement in 70% of cases, with a mean DSC of 0.92 for all index lesions. These findings show that a standardized protocol for prostatectomy pathology annotation provides reliable data on PCa localization and grading, with relatively high levels of interobserver agreement. More complicated tissue characterization, such as the presence of cribriform growth and intraductal carcinoma, remains a source of interobserver variability and should be treated with care when used in ground truth datasets.

Biopsy prostate cancer perineural invasion and tumour load are associated with positive posterolateral margins at radical prostatectomy: implications for planning of nerve-sparing surgery.

AIMS: Radical prostatectomy (RP) for prostate cancer is frequently complicated by erectile dysfunction and urinary incontinence. However, sparing of the nerve bundles adjacent to the posterolateral sides of the prostate reduces the number of complications at the risk of positive surgical margins. Preoperative selection of men eligible for safe, nerve-sparing surgery is therefore needed. Our aim was to identify pathological factors associated with positive posterolateral surgical margins in men undergoing bilateral nerve-sparing RP. METHODS AND RESULTS: Prostate cancer patients undergoing RP with standardised intra-operative surgical margin assessment according to the NeuroSAFE technique were included. Preoperative biopsies were reviewed for grade group (GG), cribriform and/or intraductal carcinoma (CR/IDC), perineural invasion (PNI), cumulative tumour length and extraprostatic extension (EPE). Of 624 included patients, 573 (91.8%) received NeuroSAFE bilaterally and 51 (8.2%) unilaterally, resulting in a total of 1197 intraoperative posterolateral surgical margin assessments. Side-specific biopsy findings were correlated to ipsilateral NeuroSAFE outcome. Higher biopsy GG, CR/IDC, PNI, EPE, number of positive biopsies and cumulative tumour length were all associated with positive posterolateral margins. In multivariable bivariate logistic regression, ipsilateral PNI [odds ratio (OR) = 2.98, 95% confidence interval (CI) = 1.62-5.48; P < 0.001] and percentage of positive cores (OR = 1.18, 95% CI = 1.08-1.29; P < 0.001) were significant predictors for a positive posterolateral margin, while GG and CR/IDC were not. CONCLUSIONS: Ipsilateral PNI and percentage of positive cores were significant predictors for a positive posterolateral surgical margin at RP. Biopsy PNI and tumour volume can therefore support clinical decision-making on the level of nerve-sparing surgery in prostate cancer patients.

Urinary Incontinence and Sexual Function After the Introduction of NeuroSAFE in Radical Prostatectomy for Prostate Cancer.

BACKGROUND: Nerve-sparing (NS) radical prostatectomy (RP) results in better functional outcomes. Intraoperative neurovascular structure-adjacent frozen section examination (NeuroSAFE) significantly increases the frequency of NS surgery. The effect of NeuroSAFE on postoperative erectile function (EF) and continence is not yet clear. OBJECTIVE: To describe EF and continence outcomes for men undergoing RP with the NeuroSAFE technique. DESIGN, SETTING, AND PARTICIPANTS: Between September 2018 and February 2021, 1034 men underwent robot-assisted RP. Data for patient-reported outcomes were collected via validated questionnaires. INTERVENTION: NeuroSAFE technique for RP. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Continence was assessed using the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) or Expanded Prostate Cancer Index Composite short form (EPIC-26) and defined as use of 0-1 pads/d. EF was evaluated using EPIC-26 or the International Index of Erectile Function short form (IIEF-5), with data converted according to the Vertosick method and categorized. Descriptive statistics were used to asses and describe tumor characteristics and continence and EF outcomes. RESULTS AND LIMITATIONS: Of the 1034 men who underwent RP after introduction of the NeuroSAFE technique, 63% and 60% completed a preoperative and at least one postoperative questionnaire on continence and EF, respectively. Of the men who underwent unilateral or bilateral NS surgery, use of 0-1 pads/d was reported by 93% after 1 yr and 96% after 2 yr; the corresponding rates for men who underwent non-NS surgery were 86% and 78%. Overall, use of 0-1 pads/d was reported by 92% of the men at 1 yr and by 94% at 2 yr after RP. Men in the NS group had a good or intermediate Vertosick score after RP more often than the non-NS group. Overall, 44% of the men had a good or intermediate Vertosick score at 1 and 2 yr after RP. CONCLUSIONS: After introduction of the NeuroSAFE technique, the continence rate was 92% at 1 yr and 94% at 2 yr after RP. The NS group had a greater percentage of men with an intermediate or good Vertosick score and a higher continence rate after RP in comparison to the non-NS group. PATIENT SUMMARY: Our study shows that after introduction of the NeuroSAFE technique during removal of the prostate, the continence rate among patients was 92% at 1 year and 94% at 2 years after surgery. Some 44% of the men had a good or intermediate score for erectile function 1 and 2 years after surgery.

Percentage Gleason pattern 4 and PI-RADS score predict upgrading in biopsy Grade Group 2 prostate cancer patients without cribriform pattern.

PURPOSE: To identify parameters to predict upgrading in biopsy Grade Group (GG) 2 prostate cancer patients without cribriform and intraductal carcinoma (CR/IDC) on biopsy. METHODS: Preoperative biopsies from 657 men undergoing radical prostatectomy (RP) for prostate cancer were reviewed for GG, presence of CR/IDC, percentage Gleason pattern 4, and tumor length. In men with biopsy GG2 without CR/IDC (n = 196), clinicopathologic features were compared between those with GG1 or GG2 without CR/IDC on RP (GG ≤ 2-) and those with GG2 with CR/IDC or any GG > 2 (GG ≥ 2+). Logistic regression analysis was used to predict upgrading in the biopsy cohort. RESULTS: In total 283 men had biopsy GG2 of whom 87 (30.7%) had CR/IDC and 196 (69.3%) did not. CR/IDC status in matched biopsy and RP specimens was concordant in 179 (63.3%) and discordant in 79 (27.9%) cases (sensitivity 45.1%; specificity 92.6%). Of 196 biopsy GG2 men without CR/IDC, 106 (54.1%) had GG ≥ 2+ on RP. Multivariable logistic regression analysis showed that age [odds ratio (OR): 1.85, 95% confidence interval (CI)1.09-3.20; p = 0.025], percentage Gleason pattern 4 (OR 1.54, 95% CI 1.17-2.07; p = 0.003), PI-RADS 5 lesion (OR 2.17, 95% CI 1.03-4.70; p = 0.045) and clinical stage T3 (OR 3.60; 95% CI 1.08-14.50; p = 0.049) were independent parameters to predict upgrading to GG ≥ 2+ on RP in these men. CONCLUSIONS: Age, clinical stage T3, percentage Gleason pattern 4 and presence of PI-RADS 5 lesions are independent predictors for upgrading in men with biopsy GG2 without CR/IDC. These findings allow for improved clinical decision-making on surveillance eligibility in intermediate-risk prostate cancer patients.

NeuroSAFE in radical prostatectomy increases the rate of nerve-sparing surgery without affecting oncological outcome.

OBJECTIVES: To investigate the impact of intra-operative neurovascular structure-adjacent frozen-section examination (NeuroSAFE) on the rate of nerve-sparing surgery (NSS) and oncological outcome in a large radical prostatectomy (RP) cohort. PATIENTS AND METHODS: Between January 2016 and December 2020, 1756 prostate cancer patients underwent robot-assisted RP, of whom 959 (55%) underwent this with NeuroSAFE and 797 (45%) without (control cohort). In cases where NeuroSAFE showed tumour in the margin, a secondary resection was performed. The effect of NeuroSAFE on NSS and positive surgical margin (PSM) status was analysed using logistic regression. Cox regression was used to identify predictors of biochemical recurrence-free survival (BCRFS). RESULTS AND LIMITATIONS: Patients in the NeuroSAFE cohort had a higher tumour grade (P < 0.001) and clinical stage (P < 0.001) than those in the control cohort. NeuroSAFE enabled more frequent NSS for both pT2 (93% vs 76%; P < 0.001) and pT3 disease (83% vs 55%; P < 0.001). In adjusted analysis, NeuroSAFE resulted in more frequent unilateral (odds ratio [OR] 3.90, 95% confidence interval (CI) 2.90-5.30; P < 0.001) and bilateral (OR 5.22, 95% CI 3.90-6.98; P < 0.001) NSS. While the PSM rate decreased from 51% to 42% in patients with pT3 stage disease (P = 0.031), NeuroSAFE was not an independent predictor of PSM status (OR 0.85, 95% CI 0.68-1.06; P = 0.2) in the entire cohort. Patients who underwent NeuroSAFE had better BCRFS compared to the control cohort (hazard ratio 0.62, 95% CI 0.45-0.84; P = 0.002). This study is limited by its comparison with a historical cohort and lack of functional outcomes. CONCLUSIONS: NeuroSAFE enables more unilateral and bilateral NSS without negatively affecting surgical margin status and biochemical recurrence. This validation study provides a comprehensive overview of the implementation, evaluation and intra-operative decision making associated with NeuroSAFE in clinical practice.

Large and small cribriform architecture have similar adverse clinical outcome on prostate cancer biopsies.

AIMS: Invasive cribriform and intraductal carcinoma (IDC) are associated with adverse outcome in prostate cancer patients, with the large cribriform pattern having the worst outcome in radical prostatectomies. Our objective was to determine the impact of the large and small cribriform patterns in prostate cancer biopsies. METHODS AND RESULTS: Pathological revision was carried out on biopsies of 1887 patients from the European Randomised Study of Screening for Prostate Cancer. The large cribriform pattern was defined as having at least twice the size of adjacent benign glands. The median follow-up time was 13.4 years. Hazard ratios for metastasis-free survival (MFS) and disease-specific survival (DSS) were calculated using Cox proportional hazards regression. Any cribriform pattern was found in 280 of 1887 men: 1.1% IDC in grade group (GG) 1, 18.2% in GG2, 57.1% in GG3, 55.4% in GG4 and 59.3% in GG5; the large cribriform pattern was present in 0, 0.5, 9.8, 18.1 and 17.3%, respectively. In multivariable analyses, small and large cribriform patterns were both (P < 0.005) associated with worse MFS [small: hazard ratio (HR) = 3.04, 95% confidence interval (CI) = 1.93-4.78; large: HR = 3.17, 95% CI = 1.68-5.99] and DSS (small: HR = 4.07, 95% CI = 2.51-6.62; large: HR = 4.13, 95% CI = 2.14-7.98). Patients with the large cribriform pattern did not have worse MFS (P = 0.77) or DSS (P = 0.96) than those with the small cribriform pattern. CONCLUSIONS: Both small and large cribriform patterns are associated with worse MFS and DSS in prostate cancer biopsies. Patients with the large cribriform pattern on biopsy have a similar adverse outcome as those with the small cribriform pattern.

Automated detection of cribriform growth patterns in prostate histology images.

Cribriform growth patterns in prostate carcinoma are associated with poor prognosis. We aimed to introduce a deep learning method to detect such patterns automatically. To do so, convolutional neural network was trained to detect cribriform growth patterns on 128 prostate needle biopsies. Ensemble learning taking into account other tumor growth patterns during training was used to cope with heterogeneous and limited tumor tissue occurrences. ROC and FROC analyses were applied to assess network performance regarding detection of biopsies harboring cribriform growth pattern. The ROC analysis yielded a mean area under the curve up to 0.81. FROC analysis demonstrated a sensitivity of 0.9 for regions larger than [Formula: see text] with on average 7.5 false positives. To benchmark method performance for intra-observer annotation variability, false positive and negative detections were re-evaluated by the pathologists. Pathologists considered 9% of the false positive regions as cribriform, and 11% as possibly cribriform; 44% of the false negative regions were not annotated as cribriform. As a final experiment, the network was also applied on a dataset of 60 biopsy regions annotated by 23 pathologists. With the cut-off reaching highest sensitivity, all images annotated as cribriform by at least 7/23 of the pathologists, were all detected as cribriform by the network and 9/60 of the images were detected as cribriform whereas no pathologist labelled them as such. In conclusion, the proposed deep learning method has high sensitivity for detecting cribriform growth patterns at the expense of a limited number of false positives. It can detect cribriform regions that are labelled as such by at least a minority of pathologists. Therefore, it could assist clinical decision making by suggesting suspicious regions.

Intraductal carcinoma has a minimal impact on Grade Group assignment in prostate cancer biopsy and radical prostatectomy specimens.

AIMS: Intraductal carcinoma (IDC) is an adverse histopathological parameter for prostate cancer outcome, but is not incorporated in current tumour grading. To account for its dismal prognosis and to omit basal cell immunohistochemistry, it has been proposed to grade IDC on the basis of its underlying architectural pattern. The aim of this study was to determine the impact of IDC grade assignment on prostate cancer biopsy and radical prostatectomy tumour grading. METHODS AND RESULTS: A cohort of 1031 prostate cancer biopsies and 835 radical prostatectomies were assigned a Grade Group according to the 2014 International Society of Urological Pathology guidelines, without incorporation of IDC in grading. Tumour grading was compared with a Grade Group in which IDC was graded on the basis of its underlying architecture. Of 1031 biopsies, 139 (13.5%) showed IDC. Grade assignment of IDC led to a Grade Group change in 17 (1.6%) cases: four of 486 (0.8%) Grade Group 1 cases were reclassified as Grade Group 2, nine of 375 (2.4%) Grade Group 2 cases were reclassified as Grade Group 3, and four of 58 (6.9%) Grade Group 4 cases were reclassified as Grade Group 5. IDC was observed in 213 of 835 (25.5%) radical prostatectomies, and its grading led to a change in tumour grade in five of 835 (0.6%) patients, with upgrading in two of 207 (1.0%) patients with Grade Group 1 cancer, in two of 420 (0.5%) patients with Grade Group 2 cancer, and in one of 50 (2%) patients with Grade Group 4 cancer. CONCLUSION: IDC grade assignment led to a Grade Group change in 1.6% of prostate biopsy specimens and in 0.6% of radical prostatectomy specimens. Although the inclusion of IDC in or the exclusion of IDC from the Grade Group might affect decision-making in individual patients, it has a minimal impact on overall prostate cancer management.

The 2019 International Society of Urological Pathology (ISUP) Consensus Conference on Grading of Prostatic Carcinoma.

Five years after the last prostatic carcinoma grading consensus conference of the International Society of Urological Pathology (ISUP), accrual of new data and modification of clinical practice require an update of current pathologic grading guidelines. This manuscript summarizes the proceedings of the ISUP consensus meeting for grading of prostatic carcinoma held in September 2019, in Nice, France. Topics brought to consensus included the following: (1) approaches to reporting of Gleason patterns 4 and 5 quantities, and minor/tertiary patterns, (2) an agreement to report the presence of invasive cribriform carcinoma, (3) an agreement to incorporate intraductal carcinoma into grading, and (4) individual versus aggregate grading of systematic and multiparametric magnetic resonance imaging-targeted biopsies. Finally, developments in the field of artificial intelligence in the grading of prostatic carcinoma and future research perspectives were discussed.

Comparison of Tumor Volume Parameters on Prostate Cancer Biopsies.

CONTEXT.­: Prostate biopsy reports require an indication of prostate cancer volume. No consensus exists on the methodology of tumor volume reporting. OBJECTIVE.­: To compare the prognostic value of different biopsy prostate cancer volume parameters. DESIGN.­: Prostate biopsies of the European Randomized Study of Screening for Prostate Cancer were reviewed (n = 1031). Tumor volume was quantified in 6 ways: average estimated tumor percentage, measured total tumor length, average calculated tumor percentage, greatest tumor length, greatest tumor percentage, and average tumor percentage of all biopsies. Their prognostic value was determined by using either logistic regression for extraprostatic expansion (EPE) and surgical margin status after radical prostatectomy (RP), or Cox regression for biochemical recurrence-free survival (BCRFS) and disease-specific survival (DSS) after RP (n = 406) and radiation therapy (RT) (n = 508). RESULTS.­: All tumor volume parameters were significantly mutually correlated (R2 > 0.500, P < .001). None were predictive for EPE, surgical margin, or BCRFS after RP in multivariable analysis, including age, prostate-specific antigen, number of positive biopsies, and grade group. In contrast, all tumor volume parameters were significant predictors for BCRFS (all P < .05) and DSS (all P < .05) after RT, except greatest tumor length. In multivariable analysis including only all tumor volume parameters as covariates, calculated tumor length was the only predictor for EPE after RP (P = .02) and DSS after RT (P = .02). CONCLUSIONS.­: All tumor volume parameters had comparable prognostic value and could be used in clinical practice. If tumor volume quantification is a threshold for treatment decision, calculated tumor length seems preferential, slightly outperforming the other parameters.

Improved Prostate Cancer Biopsy Grading by Incorporation of Invasive Cribriform and Intraductal Carcinoma in the 2014 Grade Groups.

BACKGROUND: Grade groups (GGs) are an important parameter for therapeutic decision making in prostate cancer (Pca) patients. Invasive cribriform and/or intraductal carcinoma (CR/IDC) has an independent prognostic value for disease outcome, but are not included in the GG limiting their clinical use. OBJECTIVE: To perform a proof-of-principle study incorporating CR/IDC in the current GG. DESIGN, SETTING, AND PARTICIPANTS: All prostate biopsies of 1031 men with screen-detected Pca between 1993 and 2000 were reviewed for the current GG (ranging from 1 to 5) and CR/IDC. The cribriform grade (cGrade) was equal to the GG if CR/IDC was present and GG minus 1 if not. GG1 was cGrade1 if intraductal carcinoma was absent. INTERVENTION: Biopsy review for GG and CR/IDC. A total of 406 patients had received radical prostatectomy (RP), 508 radiotherapy (RT), 108 surveillance, and eight hormonal therapy, and the treatment was unknown for one patient. Outcome measurements and statistical analysis disease-specific survival (DSS), metastasis-free survival (MFS), and biochemical recurrence-free survival (BCRFS) after 15.1 yr (interquartile range 10.9-19.7 yr) follow-up were compared using Harrell's C-statistic. RESULTS AND LIMITATIONS: The biopsy GGs were 486 GG1, 310 GG2, 104 GG3, 64 GG4, and 67 GG5; cGrade distributions were 738 cGrade1, 102 cGrade2, 91 cGrade3, 58 cGrade4, and 42 cGrade5. The cGrade had a better discriminative value than the GG for DSS (C-index 0.79; 95% confidence interval 0.74-0.83 vs 0.76; 0.71-0.82) and MFS (0.79; 0.74-0.84 vs 0.77; 0.72-0.82). The discriminative value for BCRFS after RP and RT was similar for both models. Different diagnostic, such as use of sextant biopsies, and therapeutic strategies in the 1990s are the limitations of this study. CONCLUSIONS: The cGrade is a simple Pca grade modification with better discriminative values for DSS and MFS than the GG, particularly impacting decision making in men with current GG2 Pca. PATIENT SUMMARY: Microscopic grading is an important factor for decision making in prostate cancer (Pca) patients. We show that a simple grade modification better predicts Pca outcome and might improve treatment choices.

Reporting Practices and Resource Utilization in the Era of Intraductal Carcinoma of the Prostate: A Survey of Genitourinary Subspecialists.

Intraductal carcinoma of the prostate (IDC-P) has been recently recognized by the World Health Organization classification of prostatic tumors as a distinct entity, most often occurring concurrently with invasive prostatic adenocarcinoma (PCa). Whether documented admixed with PCa or in its rare pure form, numerous studies associate this entity with clinical aggressiveness. Despite increasing clinical experience and requirement of IDC-P documentation in protocols for synoptic reporting, the specifics of its potential contribution to assessment of grade group (GG) and cancer quantitation of PCa in both needle biopsies (NBx) and radical prostatectomy (RP) specimens remain unclear. Moreover, there are no standard guidelines for incorporating basal cell marker immunohistochemistry (IHC) in the diagnosis of IDC-P, either alone or as part of a cocktail with AMACR/racemase. An online survey containing 26 questions regarding diagnosis, reporting practices, and IHC resource utilization, focusing on IDC-P, was undertaken by 42 genitourinary subspecialists from 9 countries. The degree of agreement or disagreement regarding approaches to individual questions was classified as significant majority (>75%), majority (51% to 75%), minority (26% to 50%) and significant minority (≤25%). IDC-P with or without invasive cancer is considered a contraindication for active surveillance by the significant majority (95%) of respondents, although a majority (66%) also agreed that the clinical significance/behavior of IDC-P on NBx or RP with PCa required further study. The majority do not upgrade PCa based on comedonecrosis seen only in the intraductal component in NBx (62%) or RP (69%) specimens. Similarly, recognizable IDC-P with GG1 PCa was not a factor in upgrading in NBx (78%) or RP (71%) specimens. The majority (60%) of respondents include readily recognizable IDC-P in assessment of linear extent of PCa at NBx. A significant majority (78%) would use IHC to confirm or exclude intraductal carcinoma if other biopsies showed no PCa, while 60% would use it to confirm IDC-P with invasive PCa in NBx if it would change the overall GG assignment. Nearly half (48%, a minority) would use IHC to confirm IDC-P for accurate Gleason pattern 4 quantitation. A majority (57%) report the percentage of IDC-P when present, in RP specimens. When obvious Gleason pattern 4 or 5 PCa is present in RP or NBx, IHC is rarely to almost never used to confirm the presence of IDC-P by the significant majority (88% and 90%, respectively). Most genitourinary pathologists consider IDC-P to be an adverse prognostic feature independent of the PCa grade, although recommendations for standardization are needed to guide reporting of IDC-P vis a vis tumor quantitation and final GG assessment. The use of IHC varies widely and is performed for a multitude of indications, although it is used most frequently in scenarios where confirmation of IDC-P would impact the GG assigned. Further study and best practices recommendations are needed to provide guidance with regards to the most appropriate indications for IHC use in scenarios regarding IDC-P.

Reducing unnecessary biopsies while detecting clinically significant prostate cancer including cribriform growth with the ERSPC Rotterdam risk calculator and 4Kscore.

INTRODUCTION: The use of risk calculators predicting clinically significant prostate cancer (csCaP) on biopsy reduces unnecessary biopsies and overdiagnosis of indolent disease compared to a Prostate Specific Antigen (PSA) strategy. Updating these tools using more specific outcome measures and contemporary predictors could potentially lead to further reductions. Our objective was to assess clinical impact of the 4 kallikrein (4K) score, the Rotterdam Prostate Cancer Risk Calculator (RPCRC), and the combination of both for predicting csCaP based on the latest International Society of Urological Pathology grading system and cribriform growth pattern. MATERIALS AND METHODS: Our prospective cohort consisted of 2,872 men from the first screening round in the European Randomized Study of Screening for Prostate Cancer Rotterdam; biopsy indication PSA ≥ 3.0. The predictive performance of the 4Kscore, RPCRC, and the combination of RPCRC with 4Kscore were assessed with area under the receiver operator characteristic curve (AUC) and calibration plots. Decision curve analysis was used to evaluate the reduction of unnecessary biopsy and indolent CaP. RESULTS: The csCaP was present in 242 (8%) men, and indolent CaP in 578 (20%). The 4Kscore and RPCRC had similar high AUCs (0.88 vs. 0.87; P = 0.41). The 4Kscore-RPCRC combination improved AUC to 0.89 compared to 4Kscore (P < 0.01) and RPCRC (P < 0.01). The RPCRC and 4Kscore reduced the number of Bx with 42 and 44, respectively, per 100 men at risk compared to a ≥PSA 3.0 strategy without increasing missed csCaP. The RPCRC-4Kscore combination resulted in a slight additional net reduction of 3.3 biopsies per 100 men. CONCLUSIONS: The RPCRC and 4Kscore had similar reductions of unnecessary biopsies and overdiagnosis of indolent disease. Combination of both models slightly reduced unnecessary biopsies further. Gain in net benefit must, however, be weighed against additional costs and availability of tests.

Tissue proteomics outlines AGR2 AND LOX5 as markers for biochemical recurrence of prostate cancer.

Although many patients are cured from prostate cancer (PCa) by surgery only, there are still patients who will experience rising prostate-specific antigen (PSA) levels after surgery, a condition known as biochemical recurrence (BCR). Novel protein prognostic markers in PCa tissue might enable finding better treatment for those patients experiencing BCR with a high chance of metastasis. In this study, we aimed to identify altered proteins in prostate cancer tissue, and to evaluate their potential role as prognostic markers. We used two proteomics strategies to analyse 34 prostate tumours (PCa) and 33 normal adjacent prostate (NAP) tissues. An independent cohort of 481 samples was used to evaluate the expression of three proteins: AGR2, FASN and LOX5 as prognostic markers of the disease. Tissue microarray immunohistochemical staining indicated that a low percentage of positive tumour cells for AGR2 (HR (95% CI) = 0.61 (0.43-0.93)), and a low percentage of positive tumour cells for LOX5 expression (HR (95% CI) = 2.53 (1.23-5.22)) are predictors of BCR after RP. In contrast, FASN expression had no prognostic value for PCa.

On cribriform prostate cancer.

The management of newly diagnosed prostate cancer is challenging because of its heterogeneity in histology, genetics and clinical outcome. The clinical outcome of patients with Gleason score 7 prostate cancer varies greatly. Improving risk assessment in this group is of particular interest, as Gleason score 7 prostate cancer on biopsy is an important clinical threshold for active treatment. Architecturally, four Gleason grade 4 growth patterns are recognized: ill-formed, fused, glomeruloid and cribriform. The aim of this review is to describe the role of cribriform growth in prostate cancer with respect to diagnosis, prognosis and molecular pathology. Secondly, we will discuss clinical applications for cribriform prostate cancer and give recommendations for future research.

Cribriform and intraductal prostate cancer are associated with increased genomic instability and distinct genomic alterations.

BACKGROUND: Invasive cribriform and intraductal carcinoma (CR/IDC) is associated with adverse outcome of prostate cancer patients. The aim of this study was to determine the molecular aberrations associated with CR/IDC in primary prostate cancer, focusing on genomic instability and somatic copy number alterations (CNA). METHODS: Whole-slide images of The Cancer Genome Atlas Project (TCGA, N = 260) and the Canadian Prostate Cancer Genome Network (CPC-GENE, N = 199) radical prostatectomy datasets were reviewed for Gleason score (GS) and presence of CR/IDC. Genomic instability was assessed by calculating the percentage of genome altered (PGA). Somatic copy number alterations (CNA) were determined using Fisher-Boschloo tests and logistic regression. Primary analysis were performed on TCGA (N = 260) as discovery and CPC-GENE (N = 199) as validation set. RESULTS: CR/IDC growth was present in 80/260 (31%) TCGA and 76/199 (38%) CPC-GENE cases. Patients with CR/IDC and ≥ GS 7 had significantly higher PGA than men without this pattern in both TCGA (2.2 fold; p = 0.0003) and CPC-GENE (1.7 fold; p = 0.004) cohorts. CR/IDC growth was associated with deletions of 8p, 16q, 10q23, 13q22, 17p13, 21q22, and amplification of 8q24. CNAs comprised a total of 1299 gene deletions and 369 amplifications in the TCGA dataset, of which 474 and 328 events were independently validated, respectively. Several of the affected genes were known to be associated with aggressive prostate cancer such as loss of PTEN, CDH1, BCAR1 and gain of MYC. Point mutations in TP53, SPOP and FOXA1were also associated with CR/IDC, but occurred less frequently than CNAs. CONCLUSIONS: CR/IDC growth is associated with increased genomic instability clustering to genetic regions involved in aggressive prostate cancer. Therefore, CR/IDC is a pathologic substrate for progressive molecular tumour derangement.

Characteristics and outcome of prostate cancer patients with overall biopsy Gleason score 3 + 4 = 7 and highest Gleason score 3 + 4 = 7 or > 3 + 4 = 7.

AIM: Prostate cancer heterogeneity and multifocality might result in different Gleason scores (GS) at individual biopsy cores. According to World Health Organisation/International Society of Urologic Pathology (WHO/ISUP) guidelines, the GS in each biopsy core should be recorded with optional reporting of overall GS for the entire case. We aimed to compare the clinicopathological characteristics and outcome of men with overall biopsy GS 3 + 4 = 7 with highest GS 3 + 4 = 7 (HI = OV) to those with highest GS > 3 + 4 = 7 (HI > OV). METHODS AND RESULTS: Prostate cancer biopsies from the European Randomised Study of Screening for Prostate Cancer (ERSPC) were revised according to WHO/ISUP 2014 guidelines (n = 1031). In total, 370 patients had overall GS 3 + 4 = 7, 60 of whom (16%) had had at least one biopsy core with GS 4 + 3 = 7 or 4 + 4 = 8. Men with higher GS than 3 + 4 (HI > OV) in any of the cores had higher age, prostate-specific antigen (PSA) level, number of positive biopsies, percentage tumour involvement, percentage Gleason grade 4 and cribriform or intraductal growth (all P < 0.05) than those with GS 3 + 4 = 7 at highest (HI = OV). In multivariable Cox regression analysis, including PSA, percentage positive biopsies and percentage tumour involvement, biochemical recurrence-free survival after radical prostatectomy (P = 0.52) or radiotherapy (P = 0.35) was not statistically different between both groups. CONCLUSION: Among patients with overall GS 3 + 4 = 7, those with highest GS > 3 + 4 = 7 had worse clinicopathological features, but clinical outcome was not statistically significant. Therefore, the use of overall GS instead of highest GS for clinical decision-making is justified, potentially preventing overtreatment in prostate cancer patients.

Presence of invasive cribriform or intraductal growth at biopsy outperforms percentage grade 4 in predicting outcome of Gleason score 3+4=7 prostate cancer.

Relative increase of grade 4 and presence of invasive cribriform and/or intraductal carcinoma have individually been associated with adverse outcome of Gleason score 7 (GS 7) prostate cancer. The objective of this study was to investigate the relation of Gleason grade 4 tumor percentage (%GG4) and invasive cribriform and/or intraductal carcinoma in GS 3+4=7 prostate cancer biopsies. We reviewed 1031 prostate cancer biopsies from the European Randomized Study of Screening for Prostate Cancer. In total 370 men had G3+4=7. The relation of invasive cribriform and/or intraductal carcinoma and %GG4 with biochemical recurrence-free survival (BCRFS) after radical prostatectomy (n=146) and radiation therapy (n=195) was analyzed using Cox regression. Invasive cribriform and/or intraductal carcinoma occurred in 7/121 (6%) patients with 1-10% GG4, 29/131 (22%) with 10-25%, and 52/118 (44%) with 25-50% GG4 (P<0.001). In crude analysis, both invasive cribriform and/or intraductal carcinoma (HR 2.72; 95% CI: 1.33-5.95; P=0.006) and 10-50% GG4 (HR 2.43; 95% CI: 1.10-5.37; P=0.03) were associated with BCRFS after prostatectomy. In adjusted analysis, invasive cribriform and/or intraductal carcinoma was an independent predictor for BCRFS (HR 2.40; 95% CI: 1.03-5.60; P=0.04) after prostatectomy, whereas percentage %GG4 (HR 1.00; 95% CI: 0.97-1.03; P=0.80) was not. While invasive cribriform and/or intraductal carcinoma (HR 2.58; 95% CI: 1.59-4.21; P<0.001) performed better than 10-50% GG4 (HR 1.24; 95% CI: 0.67-2.29; P=0.49) for prediction of BCRFS after radiation therapy, both parameters were insignificant in analysis adjusted for prostate-specific antigen (P=0.001), positive biopsies (P<0.001) and tumor volume (P=0.05). In conclusion, increased %GG4 is associated with invasive cribriform and/or intraductal carcinoma in GS 3+4=7 prostate cancer biopsies. Invasive cribriform and/or intraductal carcinoma is an independent parameter for BCR after prostatectomy, whereas %GG4 is not. The presence of invasive cribriform and/or intraductal carcinoma has to be included in pathology reports and should act as exclusion criterion for active surveillance.

A Prostate Cancer "Nimbosus": Genomic Instability and SChLAP1 Dysregulation Underpin Aggression of Intraductal and Cribriform Subpathologies.

BACKGROUND: Intraductal carcinoma (IDC) and cribriform architecture (CA) represent unfavorable subpathologies in localized prostate cancer. We recently showed that IDC shares a clonal ancestry with the adjacent glandular adenocarcinoma. OBJECTIVE: We investigated for the co-occurrence of "aggression" factors, genomic instability and hypoxia, and performed gene expression profiling of these tumors. DESIGN, SETTING, AND PARTICIPANTS: A total of 1325 men were treated for localized prostate cancer from four academic institutions (University Health Network, CHU de Québec-Université Laval, Memorial Sloan Kettering Cancer Center [MSKCC], and Erasmus Medical Center). Pathological specimens were centrally reviewed. Gene copy number and expression, and intraprostatic oxygenation were assessed. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: IDC/CA was separately assessed for biochemical relapse risk in the Canadian and MSKCC cohorts. Both cohorts were pooled for analyses on metastasis. RESULTS AND LIMITATION: Presence of IDC/CA independently predicted for increased risks of biochemical relapse (HRCanadian 2.17, p<0.001; HRMSKCC 2.32, p=0.0035) and metastasis (HRpooled 3.31, p<0.001). IDC/CA+ cancers were associated with an increased percentage of genome alteration (PGA [median] 7.2 vs 3.0, p<0.001), and hypoxia (64.0% vs 45.5%, p=0.17). Combinatorial genomic-pathological indices offered the strongest discrimination for metastasis (C-index 0.805 [clinical+IDC/CA+PGA] vs 0.786 [clinical+IDC/CA] vs 0.761 [clinical]). Profiling of mRNA abundance revealed that long noncoding RNA, SChLAP1, was the only gene expressed at >3-fold higher (p<0.0001) in IDC/CA+ than in IDC/CA- tumors, independently corroborated by increased SChLAP1 RNA in situ hybridization signal. Optimal treatment intensification for IDC/CA+ prostate cancer requires prospective testing. CONCLUSIONS: The poor outcome associated with IDC and CA subpathologies is associated with a constellation of genomic instability, SChLAP1 expression, and hypoxia. We posit a novel concept in IDC/CA+ prostate cancer, "nimbosus" (gathering of stormy clouds, Latin), which manifests as increased metastatic capacity and lethality. PATIENT SUMMARY: A constellation of unfavorable molecular characteristics co-occur with intraductal and cribriform subpathologies in prostate cancer. Modern imaging for surveillance and treatment intensification trials should be considered in this adverse subgroup.

Improving the Rotterdam European Randomized Study of Screening for Prostate Cancer Risk Calculator for Initial Prostate Biopsy by Incorporating the 2014 International Society of Urological Pathology Gleason Grading and Cribriform growth.

BACKGROUND: The survival rate for men with International Society of Urological Pathology (ISUP) grade 2 prostate cancer (PCa) without invasive cribriform (CR) and intraductal carcinoma (IDC) is similar to that for ISUP grade 1. If updated into the European Randomized Study of Screening for Prostate Cancer (ERSPC Rotterdam) risk calculator number 3 (RC3), this may further improve upfront selection of men who need a biopsy. OBJECTIVE: To improve the number of possible biopsies avoided, while limiting undiagnosed clinically important PCa by applying the updated RC3 for risk-based patient selection. DESIGN, SETTING, AND PARTICIPANTS: The RC3 is based on the first screening round of the ERSPC Rotterdam, which involved 3616 men. In 2015, histopathologic slides for PCa cases (n=885) were re-evaluated. Low-risk (LR) PCa was defined as ISUP grade 1 or 2 without CR/IDC. High-risk (HR) PCa was defined as ISUP grade 2 with CR/IDC and PCa with ISUP grade≥3. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We updated the RC3 using multinomial logistic regression analysis, including data on age, PSA, digital rectal examination, and prostate volume, for predicting LR and HR PCa. Predictive accuracy was quantified using receiver operating characteristic analysis and decision curve analysis. RESULTS AND LIMITATIONS: Men without PCa could effectively be distinguished from men with LR PCa and HR PCa (area under the curve 0.70, 95% confidence interval [CI] 0.68-0.72 and 0.92, 95% CI 0.90-0.94). At a 1% risk threshold, the updated calculator would lead to a 34% reduction in unnecessary biopsies, while only 2% of HR PCa cases would be undiagnosed. CONCLUSIONS: A relatively simple risk stratification tool augmented with a highly sensitive contemporary pathologic biopsy classification would result in a considerable decrease in unnecessary prostate biopsies and overdiagnosis of potentially indolent disease. PATIENT SUMMARY: We improved a well-known prostate risk calculator with a new pathology classification system that better reflects disease burden. This new risk calculator allows individualized prediction of the chance of having (potentially aggressive) biopsy-detectable prostate cancer and can guide shared decision-making when considering prostate biopsy.