Contemporary Grading for Prostate Cancer: Implications for Patient Care

Magnetic resonance imaging targeted biopsy in biopsy-naïve patients and the risk of overtreatment in prostate cancer: a grading issue

OBJECTIVE

To evaluate the impact of applying the 2014 and 2019 International Society of Urological Pathology (ISUP) recommendations on grade group distribution and concordance with radical prostatectomy (RP).

MATERIALS AND METHODS

Overall, 655 biopsy-naïve patients diagnosed by magnetic resonance imaging (MRI) targeted and systematic biopsies for Prostate Imaging Reporting and Data System score ≥3 lesions were identified from a prospectively maintained database from 2016 and 2022. Clinically significant prostate cancer was detected in 249 patients, of whom 69 underwent RP. Wilcoxon signed rank and McNemar's tests were used to compare the ISUP grade group distribution and concordance with RP after applying the 2014 (i.e., highest grade) and 2019 (i.e., global grade) ISUP recommendations, respectively.

RESULTS

Compared to the 2014 ISUP recommendations, the 2019 ISUP recommendations were associated with a significant decrease in ISUP Grade Group 4 (range of difference from -13% to -5%) and an increase in ISUP Grade Group 2 (range of difference from +6% to +11%) in MRI targeted biopsy only, MRI targeted with perilesional biopsies, and MRI targeted with systematic biopsies (all P < 0.01). In patients who underwent RP, a significant decrease in downgrading was observed with all biopsy strategies (range of difference from -19% to -12%; P ≤ 0.008), along with an increase in concordance with RP specimen (range of difference from +12% to +13%; P ≤ 0.02). The use of the 2019 ISUP recommendation was associated with RP specimen a lower treatment burden.

CONCLUSIONS

The use of the 2019 ISUP recommendations mitigates the grade migration induced by MRI targeted biopsy and improves the concordance with the final RP specimen.

Expression of oncogenic HRAS G12V causes defects in control of cell size in NIH 3T3 cells

Severe defects in control of cell size are closely associated with cancer. However, the mechanisms that drive cell size defects in cancer remain unknown and it is unclear whether they are a direct consequence of signals from primary oncogenic drivers or a secondary consequence of mutations that accumulate during evolution of cancer cells. Here, we report that expression of oncogenic HRAS G12V is sufficient to cause cell size defects in NIH 3T3 cells, which suggests that the cell size defects of cancer cells are a direct consequence of primary oncogenic drivers.

Hyperactive Ras disrupts cell size control and a key step in cell cycle entry in budding yeast

Severe defects in cell size are a nearly universal feature of cancer cells. However, the underlying causes are unknown. A previous study suggested that a hyperactive mutant of yeast Ras (ras2G19V) that is analogous to the human Ras oncogene causes cell size defects, which could provide clues to how oncogenes influence cell size. However, the mechanisms by which ras2G19V influences cell size are unknown. Here, we found that ras2G19V inhibits a critical step in cell cycle entry, in which an early G1 phase cyclin induces transcription of late G1 phase cyclins. Thus, ras2G19V drives overexpression of the early G1 phase cyclin Cln3, yet Cln3 fails to induce normal transcription of late G1 phase cyclins, leading to delayed cell cycle entry and increased cell size. ras2G19V influences transcription of late G1 phase cyclins via a poorly understood step in which Cln3 inactivates the Whi5 transcriptional repressor. Previous studies found that yeast Ras relays signals via protein kinase A (PKA); however, ras2G19V appears to influence late G1 phase cyclin expression via novel PKA-independent signaling mechanisms. Together, the data define new mechanisms by which hyperactive Ras influences cell cycle entry and cell size in yeast. Hyperactive Ras also influences expression of G1 phase cyclins in mammalian cells, but the mechanisms remain unclear. Further analysis of Ras signaling in yeast could lead to discovery of new mechanisms by which Ras family members control expression of G1 phase cyclins.

Index grade group is superior to composite grade group for prediction of biochemical recurrence following radical prostatectomy

The pathological grade of prostate cancer is the strongest predictor of recurrence. It is unclear whether the better predictor is the composite of all carcinomas within the prostate, or the highest grade lesion (index). The purpose of this study was to determine whether composite or index grade group better predicts biochemical recurrence (BCR). We undertook a retrospective analysis from a prospective institutional cohort study of men who underwent radical prostatectomy for localised prostate cancer between 2009 and 2020, in which an index and composite grade group was reported. The index grade in this study was defined as the highest grade of any tumour, usually with the highest stage, regardless of volume. Multivariate analysis and Kaplan-Meier plots were utilised. A total of 2024 men underwent radical prostatectomy during the study period; we analysed 1605 with composite grade group 2 or 3 prostate cancer. Median preoperative prostate specific antigen (PSA) was 5.9 ng/L, mean follow up was 56.8 months, 54% were pT2, 76% had multifocal disease and 16% had discordant index and composite grades. Patients with discordant index grade group had a higher risk of BCR [hazard ratio (HR) 2.22, p<0.0001]. The prevalence of BCR in the discordant group was higher at 1, 3, 5 and 7 years (4.7% vs 8.9%, 8.3% vs 18.1%, 14.5% vs 28.8% and 22.5% vs 49.5%, respectively). In cases of discordance, a higher index grade group is associated with increased rates of BCR after radical prostatectomy. Index rather than composite grade group should be used to counsel men post-operatively regarding prognosis and follow-up.

Modified the 8th AJCC staging system for patients with advanced prostate cancer: a study based on SEER database

Background

The American Joint Committee on Cancer (AJCC) 8th staging system of prostate cancer may be insufficient in predicting the prognosis of some staged patients. This study aimed to modify the AJCC 8th staging system in patients with advanced prostate cancer.

Methods

Data of patients with advanced prostate cancer from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2016 were enrolled in this cohort study. All patients were divided into the training set and the testing set with a ratio of 6:4. Multivariate Cox survival model was utilized to obtain the nomogram score for each stage variable. The modified staging system was based on the total nomogram score. The C-index and Kaplan-Meier (K-M) curves were used to show the prognostic prediction effect of patients with different staging systems.

Results

A total of 28,006 patients were included for analysis. T stage, N stage, M stage, primary Gleason pattern score, secondary Gleason pattern score, and PSA level were included as stage variables. Patients with AJCC stage III C [hazard ratio (HR) = 4.17, 95% confidence interval (CI), 3.39–5.13] and AJCC stage IV B (HR = 3.19, 95%CI, 1.79–5.69) were associated with worse prognosis compared with those of AJCC stage III B, while no statistical significance was found in patients with stage IV A (P > 0.05). In terms of the modified staging system, patients with modified stage III C (HR = 2.06, 95%CI, 1.46–2.92), modified stage IV A (HR = 6.91, 95%CI, 4.81–9.94), and modified stage IV B (HR = 21.89, 95%CI, 14.76–32.46) were associated with a poorer prognosis compared with patients with modified stage III B. The prognostic ability (C-index) of the modified staging system (0.789; 95%CI, 0.777–0.801) was better than that of the AJCC 8th edition system (0.762; 95%CI, 0.748–0.776) (0.789 vs. 0.762, P = 0.004). The K-M curves indicated that the modified staging system may be distinguished prognostic differences in patients with different stages.

Conclusion

Modified staging system may be better than AJCC 8th staging system for predicting prognosis in prostate cancer patients. The AJCC 8th staging system should be further optimized.

Recruiting an underserved, difficult to reach population into a cancer trial: Strategies from the Restore-2 Rehabilitation Trial for gay and bisexual prostate cancer patients

BACKGROUND/AIMS

Sexual minorities are small and under-researched populations that are at disproportionate risk for cancer and poor cancer outcomes. Described as a "hidden population," the principal research challenge has been to develop effective methods to identify and recruit such cancer patients into cancer studies. Online recruitment strategies, as well as targeted clinic recruitment using patient-entered sexual orientation and gender identity data from electronic medical records have potential to transform recruitment, but studies testing the effects of how to recruit using these have not been published.

METHODS

In 2019, we conducted a naturalistic, three-arm, stratified prospective study to compare three recruitment strategies: (a) clinic based recruitment of prostate cancer patients from gay health and urology clinics; (b) directly from the gay community; and (c) online recruitment (through cancer support, sex/dating, and social sites). For each strategy, we estimated time, workload, and direct costs involved. To study how recruitment strategy may affect sampling, we tested for retention rates, demographic and outcome differences across sites. Using these methods, we successfully recruited 401 gay and bisexual prostate cancer patients into a randomized, controlled, 24-month trial testing an online sexual and urinary rehabilitation curriculum tailored for this population.

RESULTS

There were seven key results. First, it is possible to recruit substantial numbers of sexual minority men into prostate cancer studies provided online recruitment methods are used. Second, we observed big differences in dropout during study onboarding by recruitment source. Third, within online recruitment, the online sex/dating application (app) was the most successful and efficient, followed by the cancer support site, and then the social networking site. Fourth, while clinics were the cheapest source of recruitment, they were time intensive and low in yield. Fifth, the cancer support site and sex/dating app recruits differed by several characteristics, with the former being more rehabilitation-focused while the latter were younger and more sexually active. Sixth, we found almost no differences in outcomes across the three online recruitment sites. Seventh, because retention in online studies has been a concern, we confirm very low attrition at 3- and 6 months into the trial.

CONCLUSION

For sexual minority cancer research, more research on how to use sexual orientation and gender identity electronic medical record data for clinic-based recruitment is needed. For other small or hard-to-reach populations, researchers should compare and publish online versus offline recruitment strategies.

Comparative Pathobiology of Canine and Human Prostate Cancer: State of the Art and Future Directions

First described in 1817, prostate cancer is considered a complex neoplastic entity, and one of the main causes of death in men in the western world. In dogs, prostatic carcinoma (PC) exhibits undifferentiated morphology with different phenotypes, is hormonally independent of aggressive character, and has high rates of metastasis to different organs. Although in humans, the risk factors for tumor development are known, in dogs, this scenario is still unclear, especially regarding castration. Therefore, with the advent of molecular biology, studies were and are carried out with the aim of identifying the main molecular mechanisms and signaling pathways involved in the carcinogenesis and progression of canine PC, aiming to identify potential biomarkers for diagnosis, prognosis, and targeted treatment. However, there are extensive gaps to be filled, especially when considering the dog as experimental model for the study of this neoplasm in humans. Thus, due to the complexity of the subject, the objective of this review is to present the main pathobiological aspects of canine PC from a comparative point of view to the same neoplasm in the human species, addressing the historical context and current understanding in the scientific field.

Racial/Ethnic Differences in Health-Related Quality of Life Among Gay and Bisexual Prostate Cancer Survivors

Introduction

Prostate cancer treatment has established effects on the health-related quality of life (HRQOL) of patients. While racial/ethnic differences in HRQOL have been explored in heterosexual patients, this is the first study to examine racial/ethnic differences in a cohort of sexual minority prostate cancer survivors.

Methods

We used data from the Restore-1 study, an online cross-sectional survey of sexual and gender minority (SGM) prostate cancer survivors in North America, to explore the association between race/ethnicity and HRQOL. General mental and physical HRQOL was assessed using the Short-Form Health Survey version 2 (SF-12). The frequency and distress of prostate cancer specific symptoms was assessed using the Expanded Prostate Cancer Composite (EPIC) scale. Multivariable linear regression was used to estimate mean differences in HRQOL between sexual minority men of color and their white, non-Hispanic counterparts after adjustment for pertinent demographic and medical characteristics.

Results

Among 190 participants, 23 (12%) self-identified as non-white and/or Hispanic. In unadjusted analysis, sexual minority men of color compared to their white counterparts reported worse HRQOL scores in the EPIC hormonal summary (73.8 vs. 81.8) and hormonal function (70.9 vs 80.5) domains. Clinically important differences between men of color and their white counterparts were seen in the EPIC bowel function (mean difference (MD): -4.5, 95% CI: -9.9, 0.8), hormonal summary (MD: -8.0, 95% CI: -15.6, -0.4), hormonal function (MD: -9.6, 95% CI: -17.6, -1.6), and hormonal bother (MD: -6.7, 95% CI: -14.4, 1.1) domains. After adjustment for covariates, clinically important differences persisted between men of color and white, non-Hispanic men on the hormonal summary (74.4 vs. 81.7), hormonal function (71.3 vs. 80.3), and hormonal bother (77.0 vs. 82.7) domains.

Conclusions

This exploratory study provides the first evidence that sexual minority men of color may have worse HRQOL outcomes compared to white, non-Hispanic sexual minority men following prostate cancer treatment.

Development and Validation of an Artificial Intelligence-Powered Platform for Prostate Cancer Grading and Quantification

IMPORTANCE

The Gleason grading system has been the most reliable tool for the prognosis of prostate cancer since its development. However, its clinical application remains limited by interobserver variability in grading and quantification, which has negative consequences for risk assessment and clinical management of prostate cancer.

OBJECTIVE

To examine the impact of an artificial intelligence (AI)-assisted approach to prostate cancer grading and quantification.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study was conducted at the University of Wisconsin-Madison from August 2, 2017, to December 30, 2019. The study chronologically selected 589 men with biopsy-confirmed prostate cancer who received care in the University of Wisconsin Health System between January 1, 2005, and February 28, 2017. A total of 1000 biopsy slides (1 or 2 slides per patient) were selected and scanned to create digital whole-slide images, which were used to develop and validate a deep convolutional neural network-based AI-powered platform. The whole-slide images were divided into a training set (n = 838) and validation set (n = 162). Three experienced academic urological pathologists (W.H., K.A.I., and R.H., hereinafter referred to as pathologists 1, 2, and 3, respectively) were involved in the validation. Data were collected between December 29, 2018, and December 20, 2019, and analyzed from January 4, 2020, to March 1, 2021.

MAIN OUTCOMES AND MEASURES

Accuracy of prostate cancer detection by the AI-powered platform and comparison of prostate cancer grading and quantification performed by the 3 pathologists using manual vs AI-assisted methods.

RESULTS

Among 589 men with biopsy slides, the mean (SD) age was 63.8 (8.2) years, the mean (SD) prebiopsy prostate-specific antigen level was 10.2 (16.2) ng/mL, and the mean (SD) total cancer volume was 15.4% (20.1%). The AI system was able to distinguish prostate cancer from benign prostatic epithelium and stroma with high accuracy at the patch-pixel level, with an area under the receiver operating characteristic curve of 0.92 (95% CI, 0.88-0.95). The AI system achieved almost perfect agreement with the training pathologist (pathologist 1) in detecting prostate cancer at the patch-pixel level (weighted κ = 0.97; asymptotic 95% CI, 0.96-0.98) and in grading prostate cancer at the slide level (weighted κ = 0.98; asymptotic 95% CI, 0.96-1.00). Use of the AI-assisted method was associated with significant improvements in the concordance of prostate cancer grading and quantification between the 3 pathologists (eg, pathologists 1 and 2: 90.1% agreement using AI-assisted method vs 84.0% agreement using manual method; P < .001) and significantly higher weighted κ values for all pathologists (eg, pathologists 2 and 3: weighted κ = 0.92 [asymptotic 95% CI, 0.90-0.94] for AI-assisted method vs 0.76 [asymptotic 95% CI, 0.71-0.80] for manual method; P < .001) compared with the manual method.

CONCLUSIONS AND RELEVANCE

In this diagnostic study, an AI-powered platform was able to detect, grade, and quantify prostate cancer with high accuracy and efficiency and was associated with significant reductions in interobserver variability. These results suggest that an AI-powered platform could potentially transform histopathological evaluation and improve risk stratification and clinical management of prostate cancer.

Multi-Dimensional Scaling Analysis of Key Regulatory Genes in Prostate Cancer Using the TCGA Database

Prostate cancer (PC) is a polygenic disease with multiple gene interactions. Therefore, a detailed analysis of its epidemiology and evaluation of risk factors can help to identify more accurate predictors of aggressive disease. We used the transcriptome data from a cohort of 243 patients from the Cancer Genome Atlas (TCGA) database. Key regulatory genes involved in proliferation activity, in the regulation of stress, and in the regulation of inflammation processes of the tumor microenvironment were selected to test a priori multi-dimensional scaling (MDS) models and create a combined score to better predict the patients' survival and disease-free intervals. Survival was positively correlated with cortisol expression and negatively with Mini-Chromosome Maintenance 7 (MCM7) and Breast-Related Cancer Antigen2 (BRCA2) expression. The disease-free interval was negatively related to the expression of enhancer of zeste homolog 2 (EZH2), MCM7, BRCA2, and programmed cell death 1 ligand 1 (PD-L1). MDS suggested two separate pathways of activation in PC. Within these two dimensions three separate clusters emerged: (1) cortisol and brain-derived neurotrophic factor BDNF, (2) PD-L1 and cytotoxic-T-lymphocyte-associated protein 4 (CTL4); (3) and finally EZH2, MCM7, BRCA2, and c-Myc. We entered the three clusters of association shown in the MDS in several Kaplan-Meier analyses. It was found that only Cluster 3 was significantly related to the interval-disease free, indicating that patients with an overall higher activity of regulatory genes of proliferation and DNA repair had a lower probability to have a longer disease-free time. In conclusion, our data study provided initial evidence that selecting patients with a high grade of proliferation and DNA repair activity could lead to an early identification of an aggressive PC with a potentials for metastatic development.

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

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

Classification of Cancer Pathology Reports: A Large-Scale Comparative Study

We report about the application of state-of-the-art deep learning techniques to the automatic and interpretable assignment of ICD-O3 topography and morphology codes to free-text cancer reports. We present results on a large dataset (more than 80 000 labeled and 1 500 000 unlabeled anonymized reports written in Italian and collected from hospitals in Tuscany over more than a decade) and with a large number of classes (134 morphological classes and 61 topographical classes). We compare alternative architectures in terms of prediction accuracy and interpretability and show that our best model achieves a multiclass accuracy of 90.3% on topography site assignment and 84.8% on morphology type assignment. We found that in this context hierarchical models are not better than flat models and that an element-wise maximum aggregator is slightly better than attentive models on site classification. Moreover, the maximum aggregator offers a way to interpret the classification process.

The Sexual Functioning of Gay and Bisexual Men Following Prostate Cancer Treatment: Results from the Restore Study

Prostate cancer is the second most common cancer in gay, bisexual, and other men who have sex with men (GBM). Few studies have assessed the effects of treatment on GBM's sexual behavior. For an online survey, 193 gay and bisexual men with prostate cancer were recruited from the North American's largest online cancer support group. Sexual functioning was measured using the Expanded Prostate Cancer Index Composite (EPIC) and a tailored Gay Sexual Functioning Inventory (GSFI). GBM have worse EPIC urinary and hormonal function and worse hormonal bother, but better sexual function and bother scores than published norms. In the GSFI, two-thirds of participants described their sexual functioning, post-treatment, as fair to poor. Only 22% reported erections sufficient for insertive anal sex. For receptive anal sex, one-third met criteria for anodyspareunia. Over half reported urination problems during sex or at orgasm. Erectile difficulties were common, severe, and a reason cited for not using condoms. Three men HIV seroconverted post-prostate cancer treatment. Differences in function and bother scores were observed by type of treatment, age, race/ethnicity, sexual orientation, but not relationship status. Sexual functioning significantly predicted long-term mental and physical health. GBM scored significantly worse on mental health and better on physical health than published norms. Sexual recovery after prostate cancer treatment is problematic for most GBM. Research to develop more effective sexual recovery, tailored to the needs of GBM treated for prostate cancer, is needed. Six implications for clinicians treating GBM with prostate cancer are identified.

The Reliability of Self-Reported Gleason Scores in Studies of Sexual Minority Prostate Cancer Survivors

In two studies, gay, bisexual, and other men who have sex with men prostate cancer survivors report lower Gleason scores than heterosexual prostate cancer survivors, leading some to speculate that men who have sex with men may have more intensive screening than other men. In the largest study of men who have sex with men prostate cancer survivors to date, 23 of 193 (11.9%) men who have sex with men prostate cancer survivors reported low Gleason scores (2-5). We contacted 14 of them, a 61 percent response rate. At second interview, most men clarified that they reported only a partial score rather than the sum score. We conclude the average lower score is not a result of differences in screening but likely measurement error. A revised Gleason item question is provided to overcome this research artifact.

Upregulation of Holliday junction recognition protein predicts poor prognosis and biochemical recurrence in patients with prostate cancer

Abnormal expression of Holliday junction recognition protein (HJURP) in several types of tumor cells plays a vital role in the formation and progression of tumors. Few studies have investigated the role of HJURP in prostate cancer (PCa). The aim of this study was to analyze the expression levels of HJURP in PCa and to establish the association with clinicopathological data. Reverse transcription quantitative polymerase chain reaction and immunohistochemical analysis were used to detect the expression levels of HJURP in benign and PCa prostate tissues. The Taylor dataset was statistically analyzed to determine if HJURP expression levels were associated with PCa clinicopathological data. HJURP was overexpressed in PCa tissues compared with benign prostate tissues. Statistical analysis of the Taylor dataset indicated that upregulation of HJURP was significantly associated with positive prostate-specific antigen (PSA) levels (P=0.004), high Gleason score (P=0.005), advanced pathological stage (P=0.007), metastasis (P<0.001) and PSA failure (P<0.001). Higher HJURP mRNA expression levels were significantly associated with shorter biochemical recurrence (BCR)-free survival (P<0.001). To the best of our knowledge, this study is the first report of HJURP upregulation in PCa tissues. Upregulation of HJURP may predict BCR-free survival and HJURP may be an oncogene that impacts the prognosis of patients with PCa.

Assessment of the Utility of Gene Positioning Biomarkers in the Stratification of Prostate Cancers

There is a pressing need for additional clinical biomarkers to predict the aggressiveness of individual cancers. Here, we examine the potential usefulness of spatial genome organization as a prognostic tool for prostate cancer. Using fluorescence in situ hybridization on formalin-fixed, paraffin embedded human prostate tissue specimens, we compared the nuclear positions of four genes between clinically relevant subgroups of prostate tissues. We find that directional repositioning of SP100 and TGFB3 gene loci stratifies prostate cancers of differing Gleason scores. A more peripheral position of SP100 and TGFB3 in the nucleus, compared to benign tissues, is associated with low Gleason score cancers, whereas more internal positioning correlates with higher Gleason scores. Conversely, LMNA is more internally positioned in many non-metastatic prostate cancers, while its position is indistinguishable from benign tissue in metastatic cancer. The false positive rates were relatively low, whereas, the false negative rates of single or combinations of genes were high, limiting the clinical utility of this assay in its current form. Nevertheless, our findings of subtype-specific gene positioning patterns in prostate cancer provides proof-of-concept for the potential usefulness of spatial gene positioning for prognostic applications, and encourage further exploration of spatial gene positioning patterns to identify novel clinically relevant molecular biomarkers, which may aid treatment decisions for cancer patients.

Down-Regulation of S100A8 is an Independent Predictor of PSA Recurrence in Prostate Cancer Treated by Radical Prostatectomy

Dysregulation of S100A8 is described in many different human tumor types, but its role in prostate cancer is unknown. To evaluate the clinical relevance of S100A8 expression in prostate cancer, a tissue microarray containing 13,665 tumors was analyzed by immunohistochemistry. Cytoplasmic S100A8 staining was compared to prostate cancer phenotype, patient prognosis and molecular features including TMPRSS2:ERG fusion status and deletions of PTEN, 3p, 5q and 6q. S100A8 immunostaining was typically seen in normal prostate tissue but lost in 60% of 9786 interpretable prostate cancers. In the remaining tumors, S100A8 was considered weak in 17.9%, moderate in 17.8% and strong in 5.4% of cases. Loss of S100A8 expression was linked to advanced tumor stage, high Gleason grade, positive nodal status, positive surgical margin and high preoperative PSA (P < .0001 each). In addition, loss of S100A8 expression was associated with TMPRSS2:ERG fusions (P < .0001), deletions of PTEN, 3p, and 6q (P < .005), and a high number of genomic deletions per tumor (P = .0009). Absence of S100A8 immunostaining was also linked to an elevated risk for early PSA recurrence (P < .0001). In a multivariate analysis limited to features that are preoperatively available, the prognostic impact of S100A8 expression (P < .0001) was independent of clinical stage, Gleason grade, and serum PSA level (P < .0001). Taken together, the results of our study demonstrate that complete loss of S100A8 expression is linked to adverse tumor features and predicts early biochemical recurrence in prostate cancer. S100A8 measurement, either alone or in combination might be of clinical utility in prostate cancers.

A critical appraisal of biomarkers in prostate cancer

PURPOSE

A number of urine and blood-based biomarker tests have been described for prostate cancer, although to date there has only been a limited exploration of the methodology behind the validation studies that underpin these tests.

METHODS

In this review, a selection of commercially available urine and blood-based biomarker tests for prostate cancer are described, and the underlying key validation studies for each test are critically appraised using the Standards for Reporting Diagnostic Accuracy (STARD) 2015 statement.

RESULTS

The ExoDx Prostate Intelliscore, SelectMDx, Progensa PCA3, Mi-Prostate Score, 4K Score, and Prostate Health Index (PHI) tests were reviewed. Most of the validation studies supporting these tests perform exploratory analyses to determine cut-off values in a post hoc manner, comprise cohorts that are primarily Caucasian, report receiver operating characteristic curves that combine the biomarker's result with established clinical nomograms and are based on a reference standard (prostate biopsy) that lacks central pathology review. Deficiencies in STARD reporting guidelines include frequent failure to provide a published study protocol, prospective study registration in a registry, a flow diagram, justification for sample size determination, a discussion of adverse events with testing, and information on how missing or indeterminate test results should be managed.

CONCLUSIONS

Key validation studies that support many commercially available urine and blood-based biomarkers for prostate cancers have deficiencies in transparency based on STARD reporting guidelines, and limitations in methodology must be considered when deciding when these tests should be applied in clinical practice.

Path R-CNN for Prostate Cancer Diagnosis and Gleason Grading of Histological Images

Prostate cancer is the most common and second most deadly form of cancer in men in the United States. The classification of prostate cancers based on Gleason grading using histological images is important in risk assessment and treatment planning for patients. Here, we demonstrate a new region-based convolutional neural network framework for multi-task prediction using an epithelial network head and a grading network head. Compared with a single-task model, our multi-task model can provide complementary contextual information, which contributes to better performance. Our model is achieved a state-of-the-art performance in epithelial cells detection and Gleason grading tasks simultaneously. Using fivefold cross-validation, our model is achieved an epithelial cells detection accuracy of 99.07% with an average area under the curve of 0.998. As for Gleason grading, our model is obtained a mean intersection over union of 79.56% and an overall pixel accuracy of 89.40%.

Circulating blood miRNAs for prostate cancer risk stratification: miRroring the underlying tumor biology with liquid biopsies

Current risk stratification methods for prostate cancer – although they have seen marked improvements over the past decades – are far from perfect. Despite the significant utility of prostate-specific antigen as a biomarker to monitor for disease recurrence, it cannot predict which tumors will recur or recommend the best treatment for patients. Similarly, although biopsies are imperative for diagnosis and staging, they are saddled with limitations and risks. We must move toward a noninvasive biomarker that has predictive and prognostic efficacy. We therefore review the current literature on circulating miRNA biomarkers, apply their use to two significant clinical problems (ie, how limitations of prostate biopsies can impact diagnosis and treatment management, and the need to tailor treatment for a clinically heterogeneous disease), and evaluate how circulating miRNAs have inherent properties that make them ideal liquid biomarkers. We also outline current gaps in knowledge that must be addressed before they can be implemented into routine clinical practice. With further research on their function and validation of their biomarker utility in large prospective cohorts, circulating miRNAs will likely prove to be the liquid biopsies of tomorrow.

Clinical factors stratifying the risk of tumor upgrading to high-grade disease in low-risk prostate cancer

PURPOSE

To identify clinical factors stratifying the risk of tumor upgrading to increasing patterns of the tumor grading system in low-risk prostate cancer (PCa).

METHODS

We evaluated the records of 438 patients who underwent radical prostatectomy. Associations between clinical factors and tumor upgrading were assessed by the univariate and multivariate multinomial logistic regression model.

RESULTS

Low-risk PCa included 170 cases (38.8%) and tumor upgrading was detected in 111 patients (65.3%): 72 (42.4%) had pathology Gleason pattern (pGP) 3 + 4, 27 (15.9%) pGP 4 + 3, and 12 (7.1%) pGP 4 + 4. Prostate- specific antigen (PSA) and proportion of positive cores (P+) were independent predictors of upgrading to high-risk disease. These factors also stratified the risk of tumor upgrading to the increasing patterns of the tumor grading system. The model allowed the identification of pGP 4 + 4. The main difference between high-risk PCa and other upgraded tumors related to PSA load (odds ratio 2.4) that associated with high volume disease in the specimen.

CONCLUSIONS

Low-risk PCa is a heterogeneous population with significant rates of tumor upgrading. Significant clinical predictors stratifying the risk of tumor upgrading to increasing patterns of the grading system included PSA and P+. These factors allowed the identification of the subset hiding high-grade disease requiring further investigations before delivering active treatments.

Nine-year prostate cancer survival differences between aggressive versus conservative therapy in men with advanced and metastatic prostate cancer

BACKGROUND

To the authors' knowledge, the survival benefit of local therapy in the setting of advanced prostate cancer remains unknown. The authors investigated whether prostate-directed treatment with either surgery or radiotherapy versus conservative treatment in the setting of locally advanced or metastatic disease was associated with improved survival within a cohort of men from the Centers for Disease Control and Prevention's (CDC) Breast and Prostate Cancer Data Quality and Patterns of Care Study (CDC POC-BP).

METHODS

Men diagnosed with locally advanced (cT3-T4 or N+ and M0) or metastatic prostate cancer were identified. The authors compared survival by treatment type, categorized as conservative (androgen deprivation therapy only) versus aggressive (radical prostatectomy or any type of radiotherapy). Nine-year overall survival and prostate cancer-specific survival were estimated using the Kaplan-Meier method. The Cox proportional hazards model was used to determine factors independently associated with 9-year prostate cancer-specific survival.

RESULTS

For men with advanced, nonmetastatic prostate cancer, conservative treatment alone was associated with a 4 times higher likelihood of prostate cancer mortality compared with men treated with surgery (hazard ratio, 4.18; 95% confidence interval, 1.44-12.14). In contrast, no difference was found between conservative versus aggressive treatment after adjusting for covariates for men with metastatic disease. The 9-year prostate cancer-specific survival rate was 27% for those receiving aggressive treatment versus 24% for men undergoing conservative treatment.

CONCLUSIONS

The authors did not observe a survival advantage with local therapy in addition to standard androgen deprivation therapy for men with metastatic prostate cancer. However, the results of the current study did affirm advantages in the setting of locally advanced disease. Aggressive local therapy in the setting of metastatic disease needs to be studied carefully before clinical adoption. Cancer 2018;124:1921-8. © 2018 American Cancer Society.

Assessment of the need for DCE MRI in the detection of dominant lesions in the whole gland: Correlation between histology and MRI of prostate cancer

The purpose of this study was to evaluate the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) in the detection of dominant prostate tumors with multi-parametric MRI of the whole gland. Combined diffusion tensor imaging (DTI) and DCE MRI from 16 patients with biopsy-proven prostate cancer and no previous treatment were acquired with a 3.0-T MRI scanner prior to radical prostatectomy, and used to identify dominant tumors. MRI results were validated by whole-mount histology. Paired t-test and Wilcoxon test, logistic generalized linear mixed effect models and receiver operating characteristic (ROC) analyses were used for the estimation of the statistical significance of the results. In the peripheral zone (PZ), the areas under the ROC curve (ROC-AUC) were 0.98 (sensitivity, 96%; specificity, 98%) for DTI, 0.96 (sensitivity, 92%; specificity, 97%) for DCE and 0.99 (sensitivity, 98%; specificity, 98%) for DTI + DCE. In the entire prostate, the ROC-AUC values were 0.96 (sensitivity, 84%; specificity, 95%) for DTI, 0.87 (sensitivity, 45%; specificity, 94%) for DCE and 0.96 (sensitivity, 88%; specificity, 98%) for DTI + DCE. The increase in ROC-AUC by the addition of DCE was not statistically significant in either PZ or the entire prostate. The results of this study have shown that DTI identified dominant tumors with high accuracy in both PZ and the entire prostate, whereas the inclusion of DCE MRI had no significant impact on the identification of either PZ or entire prostate dominant lesions. Our results suggest that the inclusion of DCE MRI may not increase the accuracy of dominant lesion detection, allowing for faster, better tolerated imaging studies.

Automatic Detection and Quantitative DCE-MRI Scoring of Prostate Cancer Aggressiveness

Purpose

To develop a robust and clinically applicable automated method for analyzing Dynamic Contrast Enhanced (DCE-) MRI of the prostate as a guide for targeted biopsies and treatments.

Materials and methods

An unsupervised pattern recognition (PR) method was used to analyze prostate DCE-MRI from 71 sequential radiotherapy patients. Identified regions of interest (ROIs) with increased perfusion were assigned either to the peripheral (PZ) or transition zone (TZ). Six quantitative features, associated with the washin and washout part of the weighted average DCE curve from the ROI, were calculated. The associations between the assigned DCE-scores and Gleason Score (GS) were investigated. A heatmap of tumor aggressiveness covering the entire prostate was generated and validated with histopathology from MRI-ultrasound fused (MRI-US) targeted biopsies.

Results

The volumes of the PR-identified ROI’s were significantly correlated with the highest GS from the biopsy session for each patient. Following normalization (and only after normalization) with gluteus maximus muscle’s DCE signal, the quantitative features in PZ were significantly correlated with GS. These correlations straightened in subset of patients with available MRI-US biopsies when GS from the individual biopsies were used. Area under the receiver operating characteristics curve for discrimination between indolent vs aggressive cancer for the significant quantitative features reached 0.88–0.95. When DCE-scores were calculated in normal appearing tissues, the features were highly discriminative for cancer vs no cancer both in PZ and TZ. The generated heatmap of tumor aggressiveness coincided with the location and GS of the MRI-US biopsies.

Conclusion

A quantitative approach for DCE-MRI analysis was developed. The resultant map of aggressiveness correlated well with tumor location and GS and is applicable for integration in radiotherapy/radiology imaging software for clinical translation.

Low-Risk Prostate Cancer and Tumor Upgrading in the Surgical Specimen: Analysis of Clinical Factors Predicting Tumor Upgrading in a Contemporary Series of Patients Who were Evaluated According to the Modified Gleason Score Grading System

OBJECTIVE

To identify significant clinical factors associated with prostate cancer (PCa) upgrading the low-risk PCa patients graded according to the modified Gleason score system.

MATERIALS AND METHODS

The logistic regression model was used to evaluate the records of 438 patients.

RESULTS

There were 170 cases (38.8%) of low-risk PCa and tumors were upgraded in 111 patients (65.3%). Only prostate specific antigen (PSA) and the proportion of positive cores (P+) were independent predictors of tumor upgrading. Further exploration was investigated by categorizing and regressing PSA (≤ 5.0 vs. > 5.0 ng/ml) and P+ (≤ 0.20 vs. > 0.20). The odds ratio of PSA > 5 ng/ml was 1.32 and of P+ > 0.20 was 2.71. The population was stratified into very low-risk with PSA ≤ 5 ng/ml and P+ ≤ 0.20 (class A), low-risk with PSA > 5 ng/ml and P+ ≤ 0.20 (class B), intermediate risk with PSA ≤ 5 ng/ml and P+ > 0.20 (class C), and high risk with PSA > 5 ng/ml and P+ 0.20 (class D). Upgrading rates were extremely low in class A (9%), extremely high in D (50.5%), and moderate (20%) in B and C.

CONCLUSION

Patients diagnosed with low-risk PCa at biopsy are a heterogeneous population because they include subsets with undetected high-grade disease. Significant clinical predictors of upgrading include the PSA value and P+. In low-risk PCa, we identified a high-risk upgrading subgroup that needed repeat biopsies in order to reclassify the tumor grade and to reassess the clinical risk category.

Gleason grade grouping of prostate cancer is of prognostic value in Asian men

AIM

The International Society of Urological Pathology made recommendations for the use of Grade Groups (GG) originally described by Epstein and colleagues over Gleason score (GS) alone in 2014, which was subsequently adopted by the WHO classification in 2016. The majority of studies validating this revision have been in Caucasian populations. We therefore asked whether the new GG system was retrospectively associated with biochemical disease-free survival in a mixed-ethnicity cohort of Asian men.

METHODS

A total of 680 radical prostatectomies (RPs) from 2005 to 2014 were included. GS from initial biopsy and RP were compared and used to allocate cases to GG, defined as: 1 (GS≤6); 2 (GS 3+4=7); 3 (GS 4+3=7); 4 (GS 4+4=8/5+3=8/3+5=8) and 5 (GS 9-10). Biochemical recurrence was defined as two consecutive post-RP prostate-specific antigen (PSA) levels of >0.2 ng/mL after post-RP PSA reaching the nadir of <0.1 ng/mL.

RESULTS

Our data showed that Kaplan-Meier analysis revealed significant differences in biochemical recurrence within Gleason GG based on either biopsy or prostatectomy scoring. Multivariate analysis further confirmed that a higher GG was significantly associated with risk of biochemical recurrence. This GG system had a higher prognostic discrimination for both initial biopsy and RP than GS.

CONCLUSIONS

Our study validates the use of the revised and updated GG system in a mixed-ethnicity population of Asian men. Higher GG was significantly associated with increased risk of biochemical recurrence. We therefore recommend its use to inform clinical management for patients with prostate cancer.

Prostate cancer: from Gleason scoring to prognostic grade grouping

The Gleason grading system was developed in the late 1960s by Dr. Donald F. Gleason. Due to changes in prostatic adenocarcinoma (PAC) detection and treatment, newer technologies to better characterize prostatic pathology, subsequently described variants of PAC and further data relating various morphologic patterns to prognosis, the application of the Gleason grading system changed substantially in surgical pathology. First in 2005 and more recently in 2014, consensus conferences were held to update PAC grading. Here, we review of the successive changes in the grading of PAC from the original system, with emphasis on the newest prognostic grade grouping.

HER2 gene amplification in patients with prostate cancer: Evaluating a CISH-based method

Prostate cancer (PCa) is one of the most widespread malignancies in the world. The role of the human epidermal growth factor receptor 2 (HER2) in the pathogenesis and progression of human PCa remains poorly understood. In contradiction with breast cancer, studies on HER2 overexpression and gene amplification in PCa have produced varying results, although the HER2 oncogene has been implicated in the biology of numerous tumor types, and serves as a prognostic marker and therapeutic target in breast cancer. Technical challenges are considered the main reasons for data discrepancies. Amplification of the HER2 gene has previously been reported in PCa, in which it was associated with tumor progression. The present study aimed to evaluate the prevalence and clinical significance of HER2 amplification in PCa. A total of 32 biopsy samples obtained from human prostate adenocarcinomas were evaluated by chromogenic in situ hybridization (CISH) to determine the frequency of patients with HER2 gene amplifications. High copy numbers of HER2 were detected in 19 of the prostate tumors analyzed. The results of the present study suggested that, in patients without amplification of HER2, high levels of prostate-specific antigen or a high Gleason score were not significantly correlated with a high pathologic stage. Furthermore, amplification levels of the HER2 gene were directly associated with pathologic stage in patients with PCa. Therefore, the potential use of HER2 as a prognostic factor or therapeutic target for PCa warrants further study.

Bilateral lymph node micrometastases and seminal vesicle invasion associated with same clinical predictors in localized prostate cancer

AIM

To determine clinical factors associated with multiple bilateral lymph node micrometastases and seminal vesicle invasion (pT3b) in organ-confined prostate cancer (PCa).

METHODS

The study excluded patients under androgen deprivation, with lymph node involvement (cN1 status), and having undergone unilateral pelvic lymph node dissection (PLND) during radical prostatectomy (RP). Lymph node micrometastases were classified as unilateral (pN1m) and bilateral (pN1b). Analysis considered multivariate multinomial logistic regression models.

RESULTS

Between January 2013 and March 2015, 140 patients underwent PLND during RP. Lymph node micrometastases were detected in 28 cases (20%) including pN1m in 19 (13.6%) and pN1b in 9 (6.4%). Independent clinical predictors of pN1b included prostate-specific antigen (PSA, µg/L) >12.5 (odds ratio [OR] = 43.0), proportion of positive biopsy cores (PBC) >0.57 (OR = 6.7), and biopsy Gleason grade (bGG) >3 (OR = 7.5). Independent pT3b predictors included PSA>12.5 (OR = 3.8), PBC>0.57 (OR = 4.1), and bGG>3 (OR = 3.8).

CONCLUSIONS

In cN0 patients with localized PCa undergoing PLND, a nonnegligible rate of multiple lymph node micrometastases was detected (32.2%). In the natural history of PCa, there is a close association between pT3b and pN1b disease. Prostate cancer patients who are at high risk of extraglandular extension need selective pelvic staging by multiparametric magnetic resonance imaging to assess seminal vesicle invasion. Operated patients with pT3b and pNx status need close PSA monitoring because of the high probability of occult multiple bilateral lymph node micrometastases.

The Role of Proteomics in Biomarker Development for Improved Patient Diagnosis and Clinical Decision Making in Prostate Cancer

Prostate Cancer (PCa) is the second most commonly diagnosed cancer in men worldwide. Although increased expression of prostate-specific antigen (PSA) is an effective indicator for the recurrence of PCa, its intended use as a screening marker for PCa is of considerable controversy. Recent research efforts in the field of PCa biomarkers have focused on the identification of tissue and fluid-based biomarkers that would be better able to stratify those individuals diagnosed with PCa who (i) might best receive no treatment (active surveillance of the disease); (ii) would benefit from existing treatments; or (iii) those who are likely to succumb to disease recurrence and/or have aggressive disease. The growing demand for better prostate cancer biomarkers has coincided with the development of improved discovery and evaluation technologies for multiplexed measurement of proteins in bio-fluids and tissues. This review aims to (i) provide an overview of these technologies as well as describe some of the candidate PCa protein biomarkers that have been discovered using them; (ii) address some of the general limitations in the clinical evaluation and validation of protein biomarkers; and (iii) make recommendations for strategies that could be adopted to improve the successful development of protein biomarkers to deliver improvements in personalized PCa patient decision making.

Extreme Gleason Upgrading From Biopsy to Radical Prostatectomy: A Population-based Analysis

OBJECTIVE

To examine the risk factors associated with the odds of extreme Gleason upgrading at radical prostatectomy (RP) (defined as a Gleason prognostic group score increase of ≥2), we utilized a large, population-based cancer registry.

MATERIALS AND METHODS

The Surveillance, Epidemiologic, and End Results database was queried (2010-2011) for all patients diagnosed with Gleason 3 + 3 or 3 + 4 on prostate needle biopsy. Available clinicopathologic factors and the odds of upgrading and extreme upgrading at RP were evaluated using multivariate logistic regression.

RESULTS

A total of 12,459 patients were identified, with a median age of 61 (interquartile range: 56-65) and a diagnostic prostate-specific antigen (PSA) of 5.5 ng/mL (interquartile range: 4.3-7.5). Upgrading was observed in 34% of men, including 44% of 7402 patients with Gleason 3 + 3 and 19% of 5057 patients with Gleason 3 + 4 disease. Age, clinical stage, diagnostic PSA, and % prostate needle biopsy cores positive were independently associated with odds of any upgrading at RP. In baseline Gleason 3 + 3 disease, extreme upgrading was observed in 6%, with increasing age, diagnostic PSA, and >50% core positivity associated with increased odds. In baseline Gleason 3 + 4 disease, extreme upgrading was observed in 4%, with diagnostic PSA and palpable disease remaining predictive. Positive surgical margins were significantly higher in patients with extreme upgrading at RP (P < .001).

CONCLUSION

Gleason upgrading at RP is common in this large population-based cohort, including extreme upgrading in a clinically significant portion.

Low-Risk Prostate Cancer and Tumor Upgrading to Higher Patterns in the Surgical Specimen. Analysis of Clinical Factors Predicting Tumor Upgrading to Higher Gleason Patterns in a Contemporary Series of Patients Who Have Been Evaluated According to the Modified Gleason Score Grading System

OBJECTIVE

To identify clinical factors associated with prostate cancer (PCA) upgrading to higher patterns of the surgical specimen in low-risk PCA.

MATERIALS AND METHODS

We evaluated the records of 438 patients. The multinomial logistic regression model was used.

RESULTS

Low-risk PCA included 170 cases (38.8%) and tumor upgrading was detected in 111 patients (65.3%) of whom 72 (42.4%) had pathological Gleason patterns (pGP) = 3 + 4 and 39 (22.9%) pGP >3 + 4. Prostate-specific antigen (PSA) and proportion of positive cores (P+) were independent predictors of tumor upgrading to higher patterns. The main difference between upgraded cancers related to PSA and to P+ >0.20. The population was stratified into risk classes by PSA ≤5 μg/l and P+ ≤0.20 (class A), PSA >5 μg/l and P+ ≤0.20 (class B), PSA ≤5 μg/l and P+ >0.20 (class C) and PSA >5 μg/l and P+ 0.20 (class D). Upgrading rates to pGP >3 + 4 were extremely low in class A (5.1%), extremely high in D (53.8%).

CONCLUSIONS

Low-risk PCA is a heterogeneous population with significant rates of undetected high-grade disease. Significant clinical predictors of upgrading to higher patterns include PSA and P+, which identify a very high-risk class that needs repeat biopsies in order to reclassify tumor grade.

Diagnosis of "Poorly Formed Glands" Gleason Pattern 4 Prostatic Adenocarcinoma on Needle Biopsy: An Interobserver Reproducibility Study Among Urologic Pathologists With Recommendations

Accurate recognition of Gleason pattern (GP) 4 prostate carcinoma (PCa) on needle biopsy is critical for patient management and prognostication. "Poorly formed glands" are the most common GP4 subpattern. We studied the diagnostic reproducibility and the quantitative threshold of grading GP4 "poorly formed glands" and the criteria to distinguish them from tangentially sectioned GP3 glands. Seventeen urologic pathologists were first queried for the definition of "poorly formed glands" using cases representing a spectrum of PCa glandular differentiation. Cancer glands with no or rare lumens, elongated compressed glands, and elongated nests were considered "poorly formed glands" by consensus. Participants then graded a second set of 23 PCa cases that potentially contained "poorly formed glands" with a fair interobserver agreement (κ = 0.34). The consensus diagnoses, defined as agreement by > 70% participants, were then correlated with the quantitative (≤ 5, 6 to 10, >10) and topographic features of poorly formed glands (clustered, immediately adjacent to, and intermixed with other well-formed PCa glands) in each case. Poorly formed glands immediately adjacent to other well-formed glands regardless of their number and small foci of ≤ 5 poorly formed glands regardless of their location were not graded as GP4. In contrast, large foci of >10 poorly formed glands that were not immediately adjacent to well-formed glands were graded as GP4. Grading "poorly formed glands" is challenging. Some morphologic features are, however, reproducible for and against a GP4 diagnosis. This study represents an important step in standardization of grading of "poorly formed glands" based on quantitative and topographic morphologic features.

Diagnosis of Gleason pattern 5 prostate adenocarcinoma on core needle biopsy: an interobserver reproducibility study among urologic pathologists

Accurate recognition of Gleason pattern 5 (GP5) prostate adenocarcinoma on needle biopsy is critical as it is associated with disease progression and adverse clinical outcome. Despite important implications of this diagnosis, interobserver variation in the diagnosis of GP5 has not been adequately studied. Digital images of 66 prostate adenocarcinoma cases that potentially contained a GP5 component were distributed to 16 urologic pathologists who were asked to classify whether GP5 was present. Each image was initially classified into 1 of 4 morphologic subpatterns by 2 coauthors (R.B.S. and M.Z.): solid nests (15), comedocarcinoma (8), single cells and/or cords (35), and variant morphology (8). Additional features captured included: size (large: >20 cells, medium: 10 to 20 cells, and small: <10 cells) and distribution of nuclei (uniform vs. nonuniform) for nests pattern; intraluminal coagulative tumor necrosis, karyorrhectic debris, and amorphous material for comedocarcinoma pattern; and quantity (≤5, 6 to 10, and >10) and distribution (clustered vs. intermixed with adjacent well-formed glands) for single cells/cords pattern. Interobserver reproducibility of a diagnosis of GP5 was assessed and the morphologic subpatterns and features were correlated with the consensus diagnosis (defined as 75% agreement). Interobserver reproducibility for overall diagnostic agreement was fair (κ=0.376). Among subpatterns, comedocarcinoma had highest reproducibility (κ=0.499), followed by variant morphology (κ=0.443), single cells/cords (κ=0.369), and nests (κ=0.347). All cases with the following features achieved consensus for GP5: large nests regardless of nuclear distribution; coagulative necrosis with or without karyorrhectic debris; single cells/cords >10 or 6 to 10 in a cluster; and signet ring-like cells in single cells or within nests pattern. A majority of cases with the following features achieved consensus against GP5: medium-size nests; exclusive intraluminal amorphous material; single cells/cords ≤5; and Paneth cell change. Remaining morphologic features did not reach consensus for or against GP5. A majority (86%) of participants would diagnose a small focus of GP5 only when it is present in >1 level. The diagnostic reproducibility of GP5 within certain morphologies was only fair among urologic pathologists. However, the diagnosis of GP5 was more reproducible when certain restrictive morphologic and quantitative criteria were applied. These findings suggest that additional studies are needed to find highly reproducible features of GP5 associated with documented aggressive clinical outcome.

Clinical Utility of Quantitative Gleason Grading in Prostate Biopsies and Prostatectomy Specimens

BACKGROUND

Gleason grading is the strongest prognostic parameter in prostate cancer. Gleason grading is categorized as Gleason ≤ 6, 3 + 4, 4 + 3, 8, and 9-10, but there is variability within these subgroups. For example, Gleason 4 components may range from 5-45% in a Gleason 3 + 4 = 7 cancer.

OBJECTIVE

To assess the clinical relevance of the fractions of Gleason patterns.

DESIGN, SETTING, AND PARTICIPANTS

Prostatectomy specimens from 12823 consecutive patients and of 2971 matched preoperative biopsies for which clinical data with an annual follow-up between 2005 and 2014 were available from the Martini-Klinik database.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

To evaluate the utility of quantitative grading, the fraction of Gleason 3, 4, and 5 patterns seen in biopsies and prostatectomies were recorded. Gleason grade fractions were compared with prostatectomy findings and prostate-specific antigen recurrence.

RESULTS AND LIMITATIONS

Our data suggest a striking utility of quantitative Gleason grading. In prostatectomy specimens, there was a continuous increase of the risk of prostate-specific antigen recurrence with increasing percentage of Gleason 4 fractions with remarkably small differences in outcome at clinically important thresholds (0% vs 5%; 40% vs 60% Gleason 4), distinguishing traditionally established prognostic groups. Also, in biopsies, the quantitative Gleason scoring identified various intermediate risk groups with respect to Gleason findings in corresponding prostatectomies. Quantitative grading may also reduce the clinical impact of interobserver variability because borderline findings such as tumors with 5%, 40%, or 60% Gleason 4 fractions and very small Gleason 5 fractions (with pivotal impact on the Gleason score) are disclaimed.

CONCLUSIONS

Quantitative Gleason pattern data should routinely be provided in addition to Gleason score categories, both in biopsies and in prostatectomy specimens.

PATIENT SUMMARY

Gleason score is the most important prognostic parameter in prostate cancer, but prone to interobserver variation. The results of our study show that morphological aspects that define the Gleason grade in prostate cancer represent a continuum. Quantitation of Gleason patterns provides clinically relevant information beyond the traditional Gleason grading categories ≤ 3 + 3, 3 + 4, 4 + 3, 8, 9 -1 0. Quantitative Gleason scoring can help to minimize variations between different pathologists and substantially aid in optimized therapy decision-making.

Machine learning approaches to analyze histological images of tissues from radical prostatectomies

Computerized evaluation of histological preparations of prostate tissues involves identification of tissue components such as stroma (ST), benign/normal epithelium (BN) and prostate cancer (PCa). Image classification approaches have been developed to identify and classify glandular regions in digital images of prostate tissues; however their success has been limited by difficulties in cellular segmentation and tissue heterogeneity. We hypothesized that utilizing image pixels to generate intensity histograms of hematoxylin (H) and eosin (E) stains deconvoluted from H&E images numerically captures the architectural difference between glands and stroma. In addition, we postulated that joint histograms of local binary patterns and local variance (LBPxVAR) can be used as sensitive textural features to differentiate benign/normal tissue from cancer. Here we utilized a machine learning approach comprising of a support vector machine (SVM) followed by a random forest (RF) classifier to digitally stratify prostate tissue into ST, BN and PCa areas. Two pathologists manually annotated 210 images of low- and high-grade tumors from slides that were selected from 20 radical prostatectomies and digitized at high-resolution. The 210 images were split into the training (n=19) and test (n=191) sets. Local intensity histograms of H and E were used to train a SVM classifier to separate ST from epithelium (BN+PCa). The performance of SVM prediction was evaluated by measuring the accuracy of delineating epithelial areas. The Jaccard J=59.5 ± 14.6 and Rand Ri=62.0 ± 7.5 indices reported a significantly better prediction when compared to a reference method (Chen et al., Clinical Proteomics 2013, 10:18) based on the averaged values from the test set. To distinguish BN from PCa we trained a RF classifier with LBPxVAR and local intensity histograms and obtained separate performance values for BN and PCa: JBN=35.2 ± 24.9, OBN=49.6 ± 32, JPCa=49.5 ± 18.5, OPCa=72.7 ± 14.8 and Ri=60.6 ± 7.6 in the test set. Our pixel-based classification does not rely on the detection of lumens, which is prone to errors and has limitations in high-grade cancers and has the potential to aid in clinical studies in which the quantification of tumor content is necessary to prognosticate the course of the disease. The image data set with ground truth annotation is available for public use to stimulate further research in this area.

Active surveillance for the management of localized prostate cancer: Guideline recommendations

INTRODUCTION

The objective is to provide guidance on the role of active surveillance (AS) as a management strategy for low-risk prostate cancer patients and to ensure that AS is offered to appropriate patients assessed by a standardized protocol. Prostate cancer is often a slowly progressive or sometimes non-progressive indolent disease diagnosed at an early stage with localized tumours that are unlikely to cause morbidity or death. Standard active treatments for prostate cancer include radiotherapy (RT) or radical prostatectomy (RP), but the harms from over diagnosis and overtreatment are of a significant concern. AS is increasingly being considered as a management strategy to avoid or delay the potential harms caused by unnecessary radical treatment.

METHODS

A literature search of MEDLINE, EMBASE, the Cochrane library, guideline databases and relevant meeting proceedings was performed and a systematic review of identified evidence was synthesized to make recommendations relating to the role of AS in the management of localized prostate cancer.

RESULTS

No exiting guidelines or reviews were suitable for use in the synthesis of evidence for the recommendations, but 59 reports of primary studies were identified. Due to studies being either non-comparative or heterogeneous, pooled meta-analyses were not conducted.

CONCLUSION

The working group concluded that for patients with low-risk (Gleason score ≤6) localized prostate cancer, AS is the preferred disease management strategy. Active treatment (RP or RT) is appropriate for patients with intermediate-risk (Gleason score 7) localized prostate cancer. For select patients with low-volume Gleason 3+4=7 localized prostate cancer, AS can be considered.

Prostate cancer diagnosis: the feasibility of needle-based optical coherence tomography

The objective of this study is to demonstrate the feasibility of needle-based optical coherence tomography (OCT) and functional analysis of OCT data along the full pullback trajectory of the OCT measurement in the prostate, correlated with pathology. OCT images were recorded using a commercially available C7-XR™ OCT Intravascular Imaging System interfaced to a C7 Dragonfly™ intravascular 0.9-mm-diameter imaging probe. A computer program was constructed for automated image attenuation analysis. First, calibration of the OCT system for both the point spread function and the system roll-off was achieved by measurement of the OCT signal attenuation from an extremely weakly scattering medium (Intralipid® 0.0005 volume%). Second, the data were arranged in 31 radial wedges (pie slices) per circular segments consisting of 16 A-scans per wedge and 5 axial B-scans, resulting in an average A-scan per wedge. Third, the decay of the OCT signal is analyzed over 50 pixels ([Formula: see text]) in depth, starting from the first found maximum data point. Fourth, for visualization, the data were grouped with a corresponding color representing a specific [Formula: see text] range according to their attenuation coefficient. Finally, the analyses were compared to histopathology. To ensure that each single use sterile imaging probe is comparable to the measurements of the other imaging probes, the probe-to-probe variations were analyzed by measuring attenuation coefficients of 0.03, 6.5, 11.4, 17, and 22.7 volume% Intralipid®. Experiments were repeated five times per probe for four probes. Inter- and intraprobe variation in the measured attenuation of Intralipid samples with scattering properties similar to that of the prostate was [Formula: see text] of the mean values. Mean attenuation coefficients in the prostate were [Formula: see text] for parts of the tissue that were classified as benign (SD: [Formula: see text], minimum: [Formula: see text], maximum: [Formula: see text]) and [Formula: see text] for parts of tissue that were classified as malignant (SD: [Formula: see text], minimum: [Formula: see text], maximum: [Formula: see text]). In benign areas, the tissue looked homogeneous, whereas in malignant areas, small glandular structures were seen. However, not all areas in which a high attenuation coefficient became apparent corresponded to areas of prostate cancer. This paper describes the first in-tissue needle-based OCT imaging and three-dimensional optical attenuation analysis of prostate tissue that indicates a correlation with pathology. Fully automated attenuation coefficient analysis was performed at 1300 nm over the full pullback. Correlation with pathology was achieved by coregistration of three-dimensional (3-D) OCT attenuation maps with 3-D pathology of the prostate. This may contribute to the current challenge of prostate imaging and the rising interest in focal therapy for reduction of side effects occurring with current therapies.

Should Gleason 6 be labeled as cancer?

PUPOSE OF REVIEW

The review covers arguments for and against removing the label of 'cancer' in Gleason score 6 prostate tumors.

RECENT FINDINGS

While there are a number of factors that determine whether men elect active surveillance, the most powerful predictor remains the Gleason score. Gleason grading remains a robust and powerful predictor of outcome in patients with prostate cancer. A pure Gleason score 6 (GS6) tumor is exceedingly unlikely to cause harm in the near term, and there have been discussions regarding whether the term cancer should still be applied. In this review, we update the largely clinico-pathological arguments that have led to the suggestion to remove the cancer label from GS6 tumors, and we provide counter arguments on the basis of practical matters of needle biopsy sampling, classical histopathology, and molecular biology findings.

SUMMARY

The implications are that by retaining the label of cancer and implementing the recently proposed concept of prognostic groups, with patients harboring GS6 tumors placed into the lowest category, there is still a strong rationale in support of the choice of active surveillance or watchful waiting for most patients with GS6 lesions.

Gleason inflation 1998-2011: a registry study of 97,168 men

OBJECTIVES

To study long-term trends in Gleason grading in a nationwide population and to assess the impact of the International Society of Urological Pathology (ISUP) revision in 2005 of the Gleason system on grading practices, as in recent years there has been a shift upwards in Gleason grading of prostate cancer.

PATIENTS AND METHODS

All newly diagnosed prostate cancers in Sweden are reported to the National Prostate Cancer Register (NPCR). In 97 168 men with a primary diagnosis of prostate cancer on needle biopsy from 1998 to 2011, Gleason score, clinical T stage (cT) and serum levels of prostate-specific antigen (s-PSA) at diagnosis were analysed.

RESULTS

Gleason score, cT stage and s-PSA were reported to the NPCR in 97%, 99% and 99% of cases. Before and after 2005, Gleason score 7-10 was diagnosed in 52% and 57%, respectively (P < 0.001). After standardisation for cT stage and s-PSA with 1998 as baseline these tumours increased from 59% to 72%. Among low-risk tumours (stage cT1 and s-PSA 4-10 ng/mL) Gleason score 7-10 increased from 16% in 1998 to 40% in 2011 (P trend < 0.001), mean 19% and 33% before and after 2005 (P < 0.001). Among high-risk tumours (stage T3 and s-PSA 20-50 ng/mL) Gleason score 7-10 increased from 65% in 1998 to 94% in 2011 (P trend < 0.001), mean 78% and 90% before and after 2005 (P < 0.001). A Gleason score of 2-5 was reported in 27% in 1998 and 1% in 2011. Gleason score 5 decreased sharply after 2005 and Gleason score 2-4 was almost abandoned.

CONCLUSIONS

There has been a gradual shift towards higher Gleason grading, which started before 2005 but became more evident after the ISUP 2005 revision. Among low-stage tumours reporting of Gleason score 7-10 was more than doubled during the study period. When corrected for stage migration upgrading is considerable over recent decades. This has clinical consequences for therapy decisions such as eligibility for active surveillance. Grading systems need to be as stable as possible to enable comparisons over time and to facilitate the interpretation of the prognostic impact of grade.

Development and clinical validation of an in situ biopsy-based multimarker assay for risk stratification in prostate cancer

PURPOSE

Prostate cancer aggressiveness and appropriate therapy are routinely determined following biopsy sampling. Current clinical and pathologic parameters are insufficient for accurate risk prediction leading primarily to overtreatment and also missed opportunities for curative therapy.

EXPERIMENTAL DESIGN

An 8-biomarker proteomic assay for intact tissue biopsies predictive of prostate pathology was defined in a study of 381 patient biopsies with matched prostatectomy specimens. A second blinded study of 276 cases validated this assay's ability to distinguish "favorable" versus "nonfavorable" pathology independently and relative to current risk classification systems National Comprehensive Cancer Network (NCCN and D'Amico).

RESULTS

A favorable biomarker risk score of ≤0.33, and a nonfavorable risk score of >0.80 (possible range between 0 and 1) were defined on "false-negative" and "false-positive" rates of 10% and 5%, respectively. At a risk score ≤0.33, predictive values for favorable pathology in very low-risk and low-risk NCCN and low-risk D'Amico groups were 95%, 81.5%, and 87.2%, respectively, higher than for these current risk classification groups themselves (80.3%, 63.8%, and 70.6%, respectively). The predictive value for nonfavorable pathology was 76.9% at biomarker risk scores >0.8 across all risk groups. Increased biomarker risk scores correlated with decreased frequency of favorable cases across all risk groups. The validation study met its two coprimary endpoints, separating favorable from nonfavorable pathology (AUC, 0.68; P < 0.0001; OR, 20.9) and GS-6 versus non-GS-6 pathology (AUC, 0.65; P < 0.0001; OR, 12.95).

CONCLUSIONS

The 8-biomarker assay provided individualized, independent prognostic information relative to current risk stratification systems, and may improve the precision of clinical decision making following prostate biopsy.

The critical role of the pathologist in determining eligibility for active surveillance as a management option in patients with prostate cancer: consensus statement with recommendations supported by the College of American Pathologists, International Society of Urological Pathology, Association of Directors of Anatomic and Surgical Pathology, the New Zealand Society of Pathologists, and the Prostate Cancer Foundation

CONTEXT

Prostate cancer remains a significant public health problem. Recent publications of randomized trials and the US Preventive Services Task Force recommendations have drawn attention to overtreatment of localized, low-risk prostate cancer. Active surveillance, in which patients undergo regular visits with serum prostate-specific antigen tests and repeat prostate biopsies, rather than aggressive treatment with curative intent, may address overtreatment of low-risk prostate cancer. It is apparent that a greater awareness of the critical role of pathologists in determining eligibility for active surveillance is needed.

OBJECTIVES

To review the state of current knowledge about the role of active surveillance in the management of prostate cancer and to provide a multidisciplinary report focusing on pathologic parameters important to the successful identification of patients likely to succeed with active surveillance, to determine the role of molecular tests in increasing the safety of active surveillance, and to provide future directions.

DESIGN

Systematic review of literature on active surveillance for low-risk prostate cancer, pathologic parameters important for appropriate stratification, and issues regarding interobserver reproducibility. Expert panels were created to delineate the fundamental questions confronting the clinical and pathologic aspects of management of men on active surveillance.

RESULTS

Expert panelists identified pathologic parameters important for management and the related diagnostic and reporting issues. Consensus recommendations were generated where appropriate.

CONCLUSIONS

Active surveillance is an important management option for men with low-risk prostate cancer. Vital to this process is the critical role pathologic parameters have in identifying appropriate candidates for active surveillance. These findings need to be reproducible and consistently reported by surgical pathologists with accurate pathology reporting.

Predicting the Gleason sum of a patient with a prostate biopsy core Gleason ≤7 and a prostate biopsy core Gleason ≥8

INTRODUCTION

We review a subset of men who had discordant prostate biopsy sums and were treated with radical prostatectomy.

METHODS

Consecutive patients treated with radical prostatectomy at The Ottawa Hospital between 2000 and 2012 were reviewed. Those with at least 1 prostate biopsy core of Gleason sum ≥8 and at least 1 prostate biopsy core of Gleason sum ≤7 cancer were included.

RESULTS

Of the 764 radical prostatectomies, 661 (87%) were eligible for the study and 35 (5%) met inclusion criteria. Of these, only 16 (46%) had prostatectomy Gleason sum of ≥8. When the highest biopsy core was Gleason sum 8 (n = 24), only 7 (29%) had a prostatectomy Gleason sum ≥8. When the highest biopsy core was Gleason 9 (n = 11), 9 (82%) had a prostatectomy Gleason sum ≥8 (relative risk [RR] 2.8; p = 0.004). Patients with clinical T3 tumours were at higher risk of Gleason sum ≥8 compared to cT1 patients (RR 3.7; p = 0.008). Patient age (p = 0.89), preoperative prostate-specific antigen (p = 0.34), prostate volume (p = 0.86), number of biopsy cores (p = 0.18), and proportion of biopsy cores with cancer (p = 0.96) were not strongly associated with risk of prostatectomy Gleason sum ≥8.

CONCLUSION

These data should be considered when assigning patients into prognostic risk categories based on prostate biopsy information. Further study to verify our findings using larger samples is warranted.