Chromosomal imbalances, loss of heterozygosity, and immunohistochemical expression of TP53, RB1, and PTEN in intraductal cancer, intraepithelial neoplasia, and invasive adenocarcinoma of the prostate

Implications of unconventional histological subtypes on magnetic resonance imaging and oncological outcomes in patients who have undergone radical prostatectomy

The prognostic significance of unconventional histology (UH) subtypes including intraductal carcinoma of the prostate (IDC-P), ductal adenocarcinoma, and cribriform pattern has been investigated for prostate cancer (PCa). However, little is known about magnetic resonance imaging (MRI) features and the oncological impact of tumor localization in localized PCa with UH. Clinical data of 211 patients with acinar adenocarcinoma (conventional histology [CH]) and 82 patients with UH who underwent robotic-assisted radical prostatectomy (RARP) were reviewed. Patients with UH are more likely to be older and have higher Gleason grade group, higher Prostate Imaging-Reporting and Data System (PI-RADS) v2.1 score, and larger tumor volume (TV) than those with CH. Multivariate analysis identified the presence of UH as an independent prognostic factor for progression-free survival (PFS) (hazard ration (HR) 2.41, 95% confidence interval (CI) 0.22-0.79, P = 0.0073). No significant difference in PFS was seen regarding tumor localization (transition zone [TZ] or peripheral zone [PZ]) in patients with UH (P = 0.8949), whereas PZ cancer showed shorter PFS in patients with CH (P = 0.0174). PCa with UH was associated with higher progression than PCa with CH among resection margin (RM)-negative cases (P < 0.0001). Further, increased PI-RADS v2.1 score did not correlate with larger TV in UH (P = 0.991), whereas a significant difference in TV was observed in CH (P < 0.0001). The prognostic significance of UH tumor was independent of tumor localization, and shorter PFS was observed even in RM-negative cases, indicating an aggressive subtype with micro-metastatic potential. Furthermore, UH tumors are more likely to harbor a large TV despite PI-RADS v2.1 score ≤ 3. These findings will help optimal perioperative management for PCa with UH.

Deciphering the genetic and epigenetic architecture of prostate cancer

Prostate cancer, one of the most frequently diagnosed cancers in men, leads to significant mortality worldwide. Its study is important due to the complexity and diversity in its progression, highlighting the urgent need for improved therapeutic strategies. This chapter probes into the genetic and epigenetic factors influencing prostate cancer progression, underscoring the importance of understanding the disease's molecular fundamentals for the development of targeted therapies. It specifically reviews the role of key genetic mutations in genes such as Androgen Receptor, TP53, SPOP, FOXA1 and PTEN which are crucial for the disease onset and a progression. Furthermore, it examines the impact of epigenetic modifications, including DNA methylation and histone modification, which contribute to the cancer's progression by affecting gene expression and cellular behavior. Further, in this chapter we delve into the underlying signaling mechanism, the advancements in targeting genetic and epigenetic alterations in prostate cancer. These findings have revealed promising targets for therapeutic advancements, aiming to understand and identify promising avenues for future therapies. This chapter improves our current understanding of prostate cancer genetic and epigenetic landscape, emphasizing the necessity of advancing our knowledge to refine and expand treatment options for prostate cancer patients.

Unveiling the Genomic Landscape of Intraductal Carcinoma of the Prostate Using Spatial Gene Expression Analysis

Intraductal carcinoma of the prostate (IDCP) has recently attracted increasing interest owing to its unfavorable prognoses. To effectively identify the IDCP-specific gene expression profile, we took a novel approach of characterizing a typical IDCP case using spatial gene expression analysis. A formalin-fixed, paraffin-embedded sample was subjected to Visium CytAssist Spatial Gene Expression analysis. IDCP within invasive prostate cancer sites was recognized as a distinct cluster separate from other invasive cancer clusters. Highly expressed genes defining the IDCP cluster, such as MUC6, MYO16, NPY, and KLK12, reflected the aggressive nature of high-grade prostate cancer. IDCP sites also showed increased hypoxia markers HIF1A, BNIP3L, PDK1, and POGLUT1; decreased fibroblast markers COL1A2, DCN, and LUM; and decreased immune cell markers CCR5 and FCGR3A. Overall, these findings indicate that the hypoxic tumor microenvironment and reduced recruitment of fibroblasts and immune cells, which reflect morphological features of IDCP, may influence the aggressiveness of high-grade prostate cancer.

Genomic and Evolutionary Characterization of Concurrent Intraductal Carcinoma and Adenocarcinoma of the Prostate

Intraductal carcinoma of the prostate (IDC-P) is a lethal prostate cancer subtype that generally coexists with invasive high-grade prostate acinar adenocarcinoma (PAC) but exhibits distinct biological features compared with concomitant adenocarcinoma. In this study, we performed whole-exome, RNA, and DNA-methylation sequencing of IDC-P, concurrent invasive high-grade PAC lesions, and adjacent normal prostate tissues isolated from 22 radical prostatectomy specimens. Three evolutionary patterns of concurrent IDC-P and PAC were identified: early divergent, late divergent, and clonally distant. In contrast to those with a late divergent evolutionary pattern, tumors with clonally distant and early divergent evolutionary patterns showed higher genomic, epigenomic, transcriptional, and pathologic heterogeneity between IDC-P and PAC. Compared with coexisting PAC, IDC-P displayed increased expression of adverse prognosis-associated genes. Survival analysis based on an independent cohort of 505 patients with metastatic prostate cancer revealed that IDC-P carriers with lower risk International Society of Urological Pathology (ISUP) grade 1-4 adenocarcinoma displayed a castration-resistant free survival as poor as those with the highest risk ISUP grade 5 tumors that lacked concurrent IDC-P. Furthermore, IDC-P exhibited robust cell-cycle progression and androgen receptor activities, characterized by an enrichment of cellular proliferation-associated master regulators and genes involved in intratumoral androgen biosynthesis. Overall, this study provides a molecular groundwork for the aggressive behavior of IDC-P and could help identify potential strategies to improve treatment of IDC-P.

SIGNIFICANCE

The genomic, transcriptomic, and epigenomic characterization of concurrent intraductal carcinoma and adenocarcinoma of the prostate deepens the biological understanding of this lethal disease and provides a genetic basis for developing targeted therapies.

Recent insights on the clinical, pathological, and molecular features of intraductal carcinoma of the prostate

Intraductal carcinoma of the prostate, a unique histopathologic entity that is often observed (especially in advanced prostate cancer), is characterized by the proliferation of malignant cells within normal acini or ducts surrounded by a basement membrane. Intraductal carcinoma of the prostate is almost invariably associated with an adjacent high-grade carcinoma and is occasionally observed as an isolated subtype. Intraductal carcinoma of the prostate has been demonstrated to be an independent poor prognostic factor for all stages of cancer, whether localized, de novo metastatic, or castration-resistant. It also has a characteristic genetic profile, including high genomic instability. Recognizing and differentiating it from other pathologies is therefore important in patient management, and morphological diagnostic criteria for intraductal carcinoma of the prostate have been established. This review summarizes and outlines the clinical and pathological features, differential diagnosis, molecular aspects, and management of intraductal carcinoma of the prostate, as described in previous studies. We also present a discussion and future perspectives regarding intraductal carcinoma of the prostate.

Molecular complexity of intraductal carcinoma of the prostate

Intraductal carcinoma of the prostate (IDC-P) is an aggressive subtype of prostate cancer characterized by the growth of tumor cells within the prostate ducts. It is often found alongside invasive carcinoma and is associated with poor prognosis. Understanding the molecular mechanisms driving IDC-P is crucial for improved diagnosis, prognosis, and treatment strategies. This review summarizes the molecular characteristics of IDC-P and their prognostic indications, comparing them to conventional prostate acinar adenocarcinoma, to gain insights into its unique behavior and identify potential therapeutic targets.

Detection of intraductal carcinoma in prostate cancer patients with small tumor volume

OBJECTIVES

The purpose of this study was to investigate intraductal carcinoma of the prostate (intraductal carcinoma) and significant cancer (SC) in patients with small tumor volume (<0.5 cm³ ) in prostatectomy specimens.

METHODS

Data from 639 patients undergoing radical prostatectomy between April 2006 and December 2017 at Chiba University Hospital and 2 affiliated institutions were retrospectively reviewed. Tumor volume in prostatectomy specimens was measured, and with a tumor volume of less than 0.5 cm³ , the presence of intraductal carcinoma and SC was examined. SC was defined as one that did not meet the definition of pathological insignificant cancer (organ-confined cancer, Grade Group 1, tumor volume < 0.5 cm³ ). The number of patients who met four active surveillance (AS) protocols was also examined.

RESULTS

A total of 83 patients with tumor volume < 0.5 cm³ were identified in this study population (SC: 43 patients [52%], intraductal carcinoma: 5 patients [6%]). The median follow-up was 34.6 months (range: 18-57 months). Four (5%) developed biochemical recurrence. The number of positive biopsy cores ≥ 2 was an independent predictor of SC in patients with tumor volume < 0.5 cm³ (hazard ratio: 4.39; 95% confidence interval: 1.67-11.56; p = 0.003). In tumor volume < 0.5 cm³ , tumor volume was significantly correlated with the International Society of Urological Pathology Grade Group (1 vs. 4-5, p = 0.002) and the presence of intraductal carcinoma (p = 0.004). In intraductal carcinoma-positive cases, four of five patients (80%) had the predictor of SC, which was two or more positive biopsy cores. Of the four AS protocols, the criteria for Prostate Cancer Research International: Active Surveillance were met most frequently in 46 cases (55%) of tumor volume less than 0.5 cm³ if targeted biopsy by magnetic resonance imaging was available.

CONCLUSION

The results of the present study suggest that intraductal carcinoma was present even in cases with small tumor volumes. Grade Group and intraductal carcinoma showed a positive correlation with tumor volume.

Evaluation of Matrix Metalloproteases by Artificial Intelligence Techniques in Negative Biopsies as New Diagnostic Strategy in Prostate Cancer

Usually, after an abnormal level of serum prostate-specific antigen (PSA) or digital rectal exam, men undergo a prostate needle biopsy. However, the traditional sextant technique misses 15-46% of cancers. At present, there are problems regarding disease diagnosis/prognosis, especially in patients' classification, because the information to be handled is complex and challenging to process. Matrix metalloproteases (MMPs) have high expression by prostate cancer (PCa) compared with benign prostate tissues. To assess the possible contribution to the diagnosis of PCa, we evaluated the expression of several MMPs in prostate tissues before and after PCa diagnosis using machine learning, classifiers, and supervised algorithms. A retrospective study was conducted on 29 patients diagnosed with PCa with previous benign needle biopsies, 45 patients with benign prostatic hyperplasia (BHP), and 18 patients with high-grade prostatic intraepithelial neoplasia (HGPIN). An immunohistochemical study was performed on tissue samples from tumor and non-tumor areas using specific antibodies against MMP -2, 9, 11, and 13, and the tissue inhibitor of MMPs -3 (TIMP-3), and the protein expression by different cell types was analyzed to which several automatic learning techniques have been applied. Compared with BHP or HGPIN specimens, epithelial cells (ECs) and fibroblasts from benign prostate biopsies before the diagnosis of PCa showed a significantly higher expression of MMPs and TIMP-3. Machine learning techniques provide a differentiable classification between these patients, with greater than 95% accuracy, considering ECs, being slightly lower when considering fibroblasts. In addition, evolutionary changes were found in paired tissues from benign biopsy to prostatectomy specimens in the same patient. Thus, ECs from the tumor zone from prostatectomy showed higher expressions of MMPs and TIMP-3 compared to ECs of the corresponding zone from the benign biopsy. Similar differences were found for expressions of MMP-9 and TIMP-3, between fibroblasts from these zones. The classifiers have determined that patients with benign prostate biopsies before the diagnosis of PCa showed a high MMPs/TIMP-3 expression by ECs, so in the zone without future cancer development as in the zone with future tumor, compared with biopsy samples from patients with BPH or HGPIN. Expression of MMP -2, 9, 11, and 13, and TIMP-3 phenotypically define ECs associated with future tumor development. Also, the results suggest that MMPs/TIMPs expression in biopsy tissues may reflect evolutionary changes from prostate benign tissues to PCa. Thus, these findings in combination with other parameters might contribute to improving the suspicion of PCa diagnosis.

Prostatın benign, prekürsör ve malign epitelyal proliferasyonlarında ERG ile PTEN ekspresyonlarının araştırılması ve bulguların klinikopatolojik korelasyonu

Amaç: Prostat kanseri farklı klinik gidişata ve geniş bir tedavi yelpazesine sahip, klinik ve moleküler olarak oldukça heterojen bir kanser türüdür. Özellikle “prostatik intraepitelyal neoplazi” (PİN), “atipik intraduktal proliferasyon” (AİP) ve “intraduktal karsinom” (İDK) benzer morfolojik özelliklere sahip olması açısından ayırıcı tanı zorluğu yaratan tanılar olup, hasta tedavi ve takibi de farklı olan antitelerdir. Çalışmamızda bu lezyonlarda ERG ve PTEN ekspresyon düzeylerini belirlemeyi ve bu biyobelirteçlerin prognostik ve diagnostik değerini araştırmayı amaçladık. Gereç ve Yöntem: EÜTF Tıbbi Patoloji Anabilim Dalında 2011-2012 yılında radikal prostatektomi veya iğne biyopsi materyallerinde “Adenokarsinom” tanısı almış 87 olgu çalışmaya alındı. Histopatolojik olarak AİP, İDK ve PİN içeren alanlar belirlendi. immunohistokimyasal olarak bu alanlarda ERG ve PTEN ekspresyonları değerlendirildi.Bulgular: Olguların 6’sında İDK, 29’unda AİP ve 52’sinde PİN belirlendi. İDK AİP, DG 3 ve üstünde olan tümörlerde daha fazla görüldü. İDK ve AİP in eşlik ettiği prostat karsinomlarının sağ kalım süresi daha kısaydı (p=0.043). İDK ve AİP içeren tümörlerde ERG ve PTEN durumu invaziv komponentle uyum içindeydi. Ayrıca tüm İDK alanlarında ERG pozitifti. PTEN ile heterojen boyanma görülmüş olup, PTEN’in invaziv karsinom ve İDK alanlarında negatifliği daha fazlaydı (p=0,63). ERG pozitifliği ve PTEN negatifliği istatistiksel olarak anlamlı olmamakla birlikte AİP tanısını desteklediği dikkati çekti.Sonuç: Özellikle ayırıcı tanı sorunu yaratan intraduktal lezyonlarda ERG pozitifliği ve PTEN negatifliği klinik öneme sahip prostat karsinomuna eşlik edebileceği için özellikle biyopsilerde gözardı edilmemeli ve hasta tedavi ile takibi buna göre yapılmalıdır.  

Cribriform Lesions of the Prostate Gland

"Cribriform lesions of the prostate represent an important and often diagnostically challenging spectrum of prostate pathology. These lesions range from normal anatomical variation, benign proliferative lesions, premalignant, suspicious to frankly malignant and biologically aggressive entities. The concept of cribriform prostate adenocarcinoma (CrP4) and intraductal carcinoma of the prostate (IDC-P), in particular, has evolved significantly in recent years with a growing body of evidence suggesting that the presence of these morphologies is important for clinical decision-making in prostate cancer management. Therefore, accurate recognition and reporting of CrP4 and IDC-P architecture are especially important. This review discusses a contemporary diagnostic approach to cribriform lesions of the prostate with a focus on their key morphologic features, differential diagnosis, underlying molecular alterations, clinical significance, and reporting recommendations."

The 2022 World Health Organization Classification of Tumors of the Urinary System and Male Genital Organs-Part B: Prostate and Urinary Tract Tumors

The 2022 World Health Organization (WHO) classification of the urinary and male genital tumors was recently published by the International Agency for Research on Cancer. This fifth edition of the WHO "Blue Book" offers a comprehensive update on the terminology, epidemiology, pathogenesis, histopathology, diagnostic molecular pathology, and prognostic and predictive progress in genitourinary tumors. In this review, the editors of the fifth series volume on urologic and male genital neoplasms present a summary of the salient changes introduced to the classification of tumors of the prostate and the urinary tract.

Intraductal Carcinoma of the Prostate as a Cause of Prostate Cancer Metastasis: A Molecular Portrait

Intraductal carcinoma of the prostate (IDC-P) is one of the most aggressive types of prostate cancer (PCa). IDC-P is identified in approximately 20% of PCa patients and is associated with recurrence, metastasis, and PCa-specific death. The main feature of this histological variant is the colonization of benign glands by PCa cells. Although IDC-P is a well-recognized independent parameter for metastasis, mechanisms by which IDC-P cells can spread and colonize other tissues are not fully known. In this review, we discuss the molecular portraits of IDC-P determined by immunohistochemistry and genomic approaches and highlight the areas in which more research is needed.

Genomic Features and Clinical Implications of Intraductal Carcinoma of the Prostate

Intraductal carcinoma of the prostate (IDC-P) is a rare and unique form of aggressive prostate carcinoma, which is characterized by an expansile proliferation of malignant prostatic epithelial cells within prostatic ducts or acini and the preservation of basal cell layers around the involved glands. The vast majority of IDC-P tumors result from adjacent high-grade invasive cancer via the retrograde spreading of tumor cells into normal prostatic ducts or acini. A subset of IDC-P tumors is rarely derived from the de novo intraductal proliferation of premalignant cells. The presence of IDC-P in biopsy or surgical specimens is significantly associated with aggressive pathologic features, such as high Gleason grade, large tumor volume, and advanced tumor stage, and with poor clinical courses, including earlier biochemical recurrence, distant metastasis, and worse survival outcomes. These architectural and behavioral features of IDC-P may be driven by specific molecular properties. Notably, IDC-P possesses distinct genomic profiles, including higher rates of TMPRSS2–ERG gene fusions and PTEN loss, increased percentage of genomic instability, and higher prevalence of germline BRCA2 mutations. Considering that IDC-P tumors are usually resistant to conventional therapies for prostate cancer, further studies should be performed to develop optimal therapeutic strategies based on distinct genomic features, such as treatment with immune checkpoint blockades or poly (adenosine diphosphate–ribose) polymerase inhibitors for patients harboring increased genomic instability or BRCA2 mutations, as well as genetic counseling with genetic testing. Patient-derived xenografts and tumor organoid models can be the promising in vitro platforms for investigating the molecular features of IDC-P tumor.

Knowing what's growing: Why ductal and intraductal prostate cancer matter

Prostate cancer is a common malignancy, but only some tumors are lethal. Accurately identifying these tumors will improve clinical practice and instruct research. Aggressive cancers often have distinctive pathologies, including intraductal carcinoma of the prostate (IDC-P) and ductal adenocarcinoma. Here, we review the importance of these pathologies because they are often overlooked, especially in genomics and preclinical testing. Pathology, genomics, and patient-derived models show that IDC-P and ductal adenocarcinoma accompany multiple markers of poor prognosis. Consequently, "knowing what is growing" will help translate preclinical research to pinpoint and treat high-risk prostate cancer in the clinic.

Androgen receptor enhancer amplification in matched patient-derived xenografts of primary and castrate-resistant prostate cancer

Amplifications of the androgen receptor (AR) occur in up to 80% of men with castration-resistant prostate cancer (CRPC). Recent studies highlighted that these amplifications not only span the AR gene but usually encompass a distal enhancer. This represents a newly recognised, non-coding mechanism of resistance to AR-directed therapies, including enzalutamide. To study disease progression before and after AR amplification, we used tumour samples from a castrate-sensitive primary tumour and castrate-resistant metastasis of the same patient. For subsequent functional and genomic studies, we established serially transplantable patient-derived xenografts (PDXs). Whole genome sequencing showed that alterations associated with poor prognosis, such as TP53 and PTEN loss, existed before androgen deprivation therapy, followed by co-amplification of the AR gene and enhancer after the development of metastatic CRPC. The PDX of the primary tumour, without the AR amplification, was sensitive to AR-directed treatments, including castration, enzalutamide, and apalutamide. The PDX of the metastasis, with the AR amplification, had higher AR and AR-V7 expression in castrate conditions, and was resistant to castration, apalutamide, and enzalutamide in vivo. Treatment with a BET inhibitor outperformed the AR-directed therapies for the metastasis, resulting in tumour regression for some, but not all, grafts. Therefore, this study provides novel matched PDXs to test potential treatments that target the overabundance of AR in tumours with AR enhancer amplifications. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Distinct Signatures of Genomic Copy Number Variants Define Subgroups of Merkel Cell Carcinoma Tumors

Simple Summary

Cancer results from genetic changes in cells. These changes are often mutations that alter the DNA sequence of critical genes. However, duplications and deletions in cancer-related genes can also contribute to malignant transformation. In this study we use Nanostring technology to assess DNA copy number changes in samples of Merkel cell carcinoma (MCC), a rare and aggressive neuroendocrine skin tumor. We were able to identify recurrent amplifications and deletions in cancer-related genes. We also found that MCC tumors grouped into three distinct copy number variant profiles. The first group consisted of tumors with multiple deletions. The second group contained tumors with low levels of genomic structural alterations. The last group comprised tumors containing multiple amplifications. Our study suggests that most MCC tumors are associated with deletions in cancer-related genes or are lacking in copy number changes, whereas a small percentage of tumors are associated with genomic amplifications.

Abstract

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin cancer. Most MCC tumors contain integrated Merkel cell polyomavirus DNA (virus-positive MCC, VP-MCC) and carry a low somatic mutation burden whereas virus-negative MCC (VN-MCC) possess numerous ultraviolet-signature mutations. In contrast to viral oncogenes and sequence mutations, little is known about genomic structural variants in MCC. To identify copy number variants in commonly altered genes, we analyzed genomic DNA from 31 tumor samples using the Nanostring nCounter copy number cancer panel. Unsupervised clustering revealed three tumor groups with distinct genomic structural variant signatures. The first cluster was characterized by multiple recurrent deletions in genes such as RB1 and WT1. The second cluster contained eight VP-MCC and displayed very few structural variations. The final cluster contained one VP-MCC and four VN-MCC with predominantly genomic amplifications in genes like MDM4, SKP2, and KIT and deletions in TP53. Overall, VN-MCC contained more structure variation than VP-MCC but did not cluster separately from VP-MCC. The observation that most MCC tumors demonstrate a deletion-dominated structural group signature, independent of virus status, suggests a shared pathophysiology among most VP-MCC and VN-MCC tumors.

Androgen-Driven Fusion Genes and Chimeric Transcripts in Prostate Cancer

Androgens are steroid hormones governing the male reproductive development and function. As such, androgens and the key mediator of their effects, androgen receptor (AR), have a leading role in many diseases. Prostate cancer is a major disease where AR and its transcription factor function affect a significant number of patients worldwide. While disease-related AR-driven transcriptional programs are connected to the presence and activity of the receptor itself, also novel modes of transcriptional regulation by androgens are exploited by cancer cells. One of the most intriguing and ingenious mechanisms is to bring previously unconnected genes under the control of AR. Most often this occurs through genetic rearrangements resulting in fusion genes where an androgen-regulated promoter area is combined to a protein-coding area of a previously androgen-unaffected gene. These gene fusions are distinctly frequent in prostate cancer compared to other common solid tumors, a phenomenon still requiring an explanation. Interestingly, also another mode of connecting androgen regulation to a previously unaffected gene product exists via transcriptional read-through mechanisms. Furthermore, androgen regulation of fusion genes and transcripts is not linked to only protein-coding genes. Pseudogenes and non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) can also be affected by androgens and de novo functions produced. In this review, we discuss the prevalence, molecular mechanisms, and functional evidence for androgen-regulated prostate cancer fusion genes and transcripts. We also discuss the clinical relevance of especially the most common prostate cancer fusion gene TMPRSS2-ERG, as well as present open questions of prostate cancer fusions requiring further investigation.

The presence of intraductal carcinoma of the prostate is closely associated with poor prognosis: a systematic review and meta-analysis

We aimed to confirm the predictive ability of the presence of intraductal carcinoma of the prostate (IDC-P) for prognosis and the associations between IDC-P and clinicopathological parameters. Studies were identified in PubMed, Cochrane Library, EMBASE, Web of Science, and SCOPUS up to December 1, 2019. Hazard ratios (HRs) for survival data and odds ratios for clinicopathological data with 95% confidence intervals (CIs) were extracted. Heterogeneity was evaluated by the I² value, and quality was assessed by the Newcastle–Ottawa Scale criteria. A total of 4179 patients from 13 studies were included. The results showed that IDC-P presence was significantly associated with poor progression-free survival (PFS; HR = 2.31; 95% CI: 1.96–2.73), cancer-specific survival (HR = 1.89; 95% CI: 1.28–2.77), and overall survival (HR = 2.14; 95% CI: 1.53–3.01). In the subgroup analysis, IDC-P presence was significantly associated with poor PFS in prostate cancer treated by radical prostatectomy (HR = 2.48; 95% CI: 2.05–3.00) and treated by radiotherapy (HR = 2.83; 95% CI: 1.65–4.85). Regarding clinicopathological characteristics, patients with IDC-P presence had significantly higher tumor clinical stages, Gleason scores, probabilities of lymph node invasion, positive surgical margins, and positive extraprostatic extension. Our meta-analysis indicates that the presence of IDC-P is closely associated with poor prognosis and adverse clinicopathological characteristics. Our data support the value and clinical utility of the routine detection of IDC-P by pathological examination. These conclusions need further validation, and prospective studies are needed to find better treatment modalities other than traditional first-line therapy for patients with IDC-P.

Intraductal Carcinoma of the Prostate: Pathogenesis and Molecular Perspectives

Intraductal carcinoma of the prostate (IDC-P), a clinicopathological entity characterized by malignant prostatic epithelial cells growing within ducts and/or acini, has a distinct architectural pattern, cytological features, and biological behavior. Whereas most IDC-P tumors could be derived from adjacent high-grade invasive cancer via retrograde spreading of cancer cells along benign ducts and acini, a small subset of IDC-P may arise from the transformation and intraductal proliferation of precancerous cells induced by various oncogenic events. These isolated IDC-P tumors possess a distinct mutational profile and may function as a carcinoma in situ lesion with de novo intraductal outgrowth of malignant cells. Further molecular characterization of these two types of IDC-P and better understanding of the mechanisms underlying IDC-P formation and progression could be translated into valuable biomarkers for differential diagnosis and actionable targets for therapeutic interventions. PATIENT SUMMARY: Intraductal carcinoma of the prostate is an aggressive type of prostate cancer associated with high risk for local recurrence and distant metastasis. In this review, we discussed pathogenesis, biomarkers, differential diagnoses, and therapeutic strategies for this tumor.

Intraductal carcinoma of the prostate

Intraductal carcinoma of the prostate (IDC-P) is a diagnostic entity characterized by architecturally or cytologically malignant-appearing prostatic glandular epithelium confined to prostatic ducts. Despite its apparent in situ nature, this lesion is associated with aggressive prostatic adenocarcinoma and is a predictor for poor prognosis when identified on biopsy or radical prostatectomy. This review discusses diagnosis, clinical features, histogenesis, and management of IDC-P, as well as current research and controversies surrounding this entity.

Loss of heterozygosity and immunoexpression of PTEN in oral epithelial dysplasia and squamous cell carcinoma

INTRODUCTION

Oral epithelial dysplasia (OED) is a risk factor for developing subsequent oral squamous cell carcinoma (OSCC). Loss of heterozygosity (LOH) profiles have been validated as risk predictors of malignant transformation of OED. It is still unclear if Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) allelic loss also occurs in initial stage malignant lesions and if the allelic loss is involved as one of the mechanisms of oral carcinogenesis. Thus, this study objective investigate LOH of PTEN gene and the immunohistochemical expression of the protein in OED and OSCC samples.

MATERIAL AND METHODS

Formalin-fixed paraffin-embedded samples of 19 OEDs and 16 OSCCs were included to immunohistochemistry and LOH analysis. Two polymorphic microsatellite markers (AFMA086WG9 and D10S1765) located in chromosome 10 were used in this study for LOH analysis. For immunohistochemical analysis, 5 random fields with 400× magnification were evaluated quantitatively and qualitatively in epithelial and neoplastic cells.

RESULTS

AFMA086WG9 marker only demonstrated LOH in OEDs cases (10.5%). D10S1765 marker demonstrated LOH in 57.2% of OEDs and 50% of OSCCs. Higher nuclear immunostaining was detected in cases of OSCCs when compared to OEDs (p < .001) and there was strong cytoplasmic immunoexpression in OSCCs (p < .045).

CONCLUSIONS

We provide evidence that the allelic loss of PTEN is present in premalignant oral lesions and OSCCs, however the LOH of PTEN does not seems to influence its protein expression.

Molecular profiling of radical prostatectomy tissue from patients with no sign of progression identifies ERG as the strongest independent predictor of recurrence

BACKGROUND

As a major cause of morbidity and mortality among men, prostate cancer is a heterogenous disease, with a vast heterogeneity in the biology of the disease and in clinical outcome. While it often runs an indolent course, local progression or metastasis may eventually develop, even among patients considered "low risk" at diagnosis. Therefore, biomarkers that can discriminate aggressive from indolent disease at an early stage would greatly benefit patients. We hypothesized that tissue specimens from early stage prostate cancers may harbor predictive signatures for disease progression.

METHODS

We used a cohort of radical prostatectomy patients with longitudinal follow-up, who had tumors with low grade and stage that revealed no signs of future disease progression at surgery. During the follow-up period, some patients either remained indolent (non-BCR) or progressed to biochemical recurrence (BCR). Total RNA was extracted from tumor, and adjacent normal epithelium of formalin-fixed-paraffin-embedded (FFPE) specimens. Differential gene expression in tumors, and in tumor versus normal tissues between BCR and non-BCR patients were analyzed by NanoString using a customized CodeSet of 151 probes.

RESULTS

After controlling for false discovery rates, we identified a panel of eight genes (ERG, GGT1, HDAC1, KLK2, MYO6, PLA2G7, BICD1 and CACNAID) that distinguished BCR from non-BCR patients. We found a clear association of ERG expression with non-BCR, which was further corroborated by quantitative RT-PCR and immunohistochemistry assays.

CONCLUSIONS

Our results identified ERG as the strongest predictor for BCR and showed that potential prognostic prostate cancer biomarkers can be identified from FFPE tumor specimens.

Intraductal carcinoma of the prostate: a critical re-appraisal

Intraductal carcinoma of the prostate gland (IDCP), which is now categorised as a distinct entity by WHO 2016, includes two biologically distinct diseases. IDCP associated with invasive carcinoma (IDCP-inv) generally represents a growth pattern of invasive prostatic adenocarcinoma while the rarely encountered pure IDCP is a precursor of prostate cancer. This review highlights issues that require further discussion and clarification. The diagnostic criterion “nuclear size at least 6 times normal” is ambiguous as “size” could refer to either nuclear area or diameter. If area, then this criterion could be re-defined as nuclear diameter at least three times normal as it is difficult to visually compare area of nuclei. It is also unclear whether IDCP could also include tumours with ductal morphology. There is no consensus whether pure IDCP in needle biopsies should be managed with re-biopsy or radical therapy. A pragmatic approach would be to recommend radical therapy only for extensive pure IDCP that is morphologically unequivocal for high-grade prostate cancer. Active surveillance is not appropriate when low-grade invasive cancer is associated with IDCP, as such patients usually have unsampled high-grade prostatic adenocarcinoma. It is generally recommended that IDCP component of IDCP-inv should be included in tumour extent but not grade. However, there are good arguments in favour of grading IDCP associated with invasive cancer. All historical as well as contemporary Gleason outcome data are based on morphology and would have included an associated IDCP component in the tumour grade. WHO 2016 recommends that IDCP should not be graded, but it is unclear whether this applies to both pure IDCP and IDCP-inv.

Improving adenoviral vectors and strategies for prostate cancer gene therapy

Gene therapy has been evaluated for the treatment of prostate cancer and includes the application of adenoviral vectors encoding a suicide gene or oncolytic adenoviruses that may be armed with a functional transgene. In parallel, versions of adenoviral vector expressing the p53 gene (Ad-p53) have been tested as treatments for head and neck squamous cell carcinoma and non-small cell lung cancer. Although Ad-p53 gene therapy has yielded some interesting results when applied to prostate cancer, it has not been widely explored, perhaps due to current limitations of the approach. To achieve better functionality, improvements in the gene transfer system and the therapeutic regimen may be required. We have developed adenoviral vectors whose transgene expression is controlled by a p53-responsive promoter, which creates a positive feedback mechanism when used to drive the expression of p53. Together with improvements that permit efficient transduction, this new approach was more effective than the use of traditional versions of Ad-p53 in killing prostate cancer cell lines and inhibiting tumor progression. Even so, gene therapy is not expected to replace traditional chemotherapy but should complement the standard of care. In fact, chemotherapy has been shown to assist in viral transduction and transgene expression. The cooperation between gene therapy and chemotherapy is expected to effectively kill tumor cells while permitting the use of reduced chemotherapy drug concentrations and, thus, lowering side effects. Therefore, the combination of gene therapy and chemotherapy may prove essential for the success of both approaches.

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.

Precursor Lesions of Urologic Malignancies

CONTEXT

- Precursor lesions of urologic malignancies are established histopathologic entities, which are important not only to recognize for clinical purposes, but also to further investigate at the molecular level in order to gain a better understanding of the pathogenesis of these malignancies.

OBJECTIVE

- To provide a brief overview of precursor lesions to the most common malignancies that develop within the genitourinary tract with a focus on their clinical implications, histologic features, and molecular characteristics.

DATA SOURCES

- Literature review from PubMed, urologic pathology textbooks, and the 4th edition of the World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs. All photomicrographs were taken from cases seen at Weill Cornell Medicine or from the authors' personal slide collections.

CONCLUSIONS

- The clinical importance and histologic criteria are well established for the known precursor lesions of the most common malignancies throughout the genitourinary tract, but further investigation is warranted at the molecular level to better understand the pathogenesis of these lesions. Such investigation may lead to better risk stratification of patients and potentially novel treatments.

Biomarker, Molecular, and Technologic Advances in Urologic Pathology, Oncology, and Imaging

Urologic pathology is evolving rapidly. Emerging trends include the expanded diagnostic utility of biomarkers and molecular testing, as well as adapting to the plethora of technical advances occurring in genitourinary oncology, surgical practice, and imaging. We illustrate those trends by highlighting our approach to the diagnostic workup of a few selected disease entities that pathologists may encounter, including newly recognized subtypes of renal cell carcinoma, pheochromocytoma, and prostate cancer, some of which harbor a distinctive chromosomal translocation, gene loss, or mutation. We illustrate applications of immunohistochemistry for differential diagnosis of needle core renal biopsies, intraductal carcinoma of the prostate, and amyloidosis and cite encouraging results from early studies using targeted gene expression panels to predict recurrence after prostate cancer surgery. At our institution, pathologists are working closely with urologic surgeons and interventional radiologists to explore the use of intraoperative frozen sections for margins and nerve sparing during robotic prostatectomy, to pioneer minimally invasive videoscopic inguinal lymphadenectomy, and to refine image-guided needle core biopsies and cryotherapy of prostate cancer as well as blue-light/fluorescence cystoscopy. This collaborative, multidisciplinary approach enhances clinical management and research, and optimizes the care of patients with urologic disorders.

Intraductal Carcinoma of the Prostate Gland: Recent Advances

Intraductal carcinoma of the prostate (IDC-P) is characterized by prostatic carcinoma involving ducts and/or acini. The presence of IDC-P is usually associated with a high-grade Gleason score, large tumor volume, and adverse prognostic parameters, including extraprostatic extension and seminal vesicle invasion. When present, IDC-P is associated with worse outcomes, regardless of treatment status. IDC-P is included in a broader diagnostic category of atypical cribriform lesions of the prostate gland. This category of lesions also includes high-grade prostatic intraepithelial neoplasia (HGPIN), urothelial carcinoma involving prostatic ducts or acini, and prostatic ductal adenocarcinoma, amongst other intraductal proliferations. Differentiating between these entities is important as they have differing therapeutic and prognostic implications for patients, although differential diagnosis thereof is not always straightforward. The present review discusses IDC-P in regards to its morphological characteristics, molecular features, and clinical outcomes. Given the current state of knowledge, the presence of IDC-P should be evaluated and documented correctly in both radical prostatectomy and needle biopsy specimens, and the clinical implications thereof should be taken into consideration during treatment and follow up.

Advances in genetics: widening our understanding of prostate cancer

Prostate cancer is a leading cause of cancer-related death in Western men. Our understanding of the genetic alterations associated with disease predisposition, development, progression, and therapy response is rapidly improving, at least in part, owing to the development of next-generation sequencing technologies. Large advances have been made in our understanding of the genetics of prostate cancer through the application of whole-exome sequencing, and this review summarises recent advances in this field and discusses how exome sequencing could be used clinically to promote personalised medicine for prostate cancer patients.

Disease-specific survival of patients with invasive cribriform and intraductal prostate cancer at diagnostic biopsy

Invasive cribriform and intraductal carcinoma in radical prostatectomy specimens have been associated with an adverse clinical outcome. Our objective was to determine the prognostic value of invasive cribriform and intraductal carcinoma in pre-treatment biopsies on time to disease-specific death. We pathologically revised the diagnostic biopsies of 1031 patients from the first screening round of the European Randomized Study of Screening for Prostate Cancer (1993-2000). Ninety percent of all patients (n=923) had received active treatment, whereas 10% (n=108) had been followed by watchful waiting. The median follow-up was 13 years. Patients who either had invasive cribriform growth pattern or intraductal carcinoma were categorized as CR/IDC+. The outcome was disease-specific survival. Relationships with outcome were analyzed using multivariable Cox regression and log-rank analysis. In total, 486 patients had Gleason score 6 (47%) and 545 had ≥7 (53%). The 15-year disease-specific-survival probabilities were 99% in Gleason score 6 (n=486), 94% in CR/IDC- Gleason score ≥7 (n=356) and 67% in CR/IDC+ Gleason score ≥7 (n=189). CR/IDC- Gleason score 3+4=7 patients did not have statistically different survival probabilities from those with Gleason score 6 (P=0.30), while CR/IDC+ Gleason score 3+4=7 patients did (P<0.001). In multivariable analysis, CR/IDC+ status was independently associated with a poorer disease-specific survival (HR 2.6, 95% CI 1.4-4.8, P=0.002). We conclude that CR/IDC+ status in prostate cancer biopsies is associated with a worse disease-specific survival. Our findings indicate that men with biopsy CR/IDC- Gleason score 3+4=7 prostate cancer could be candidates for active surveillance, as these patients have similar survival probabilities to those with Gleason score 6.

Intraductal carcinoma of prostate (IDC-P): from obscure to significant

The concept of intraductal carcinoma of prostate (IDC-P) has evolved over the years and its clinicopathologic significance has come to be more clearly appreciated. In contrast to morphologically malignant intraductal lesions that represent earlier stages of the malignant process in other anatomic sites such as the breast, IDC-P has now been generally recognized as a prognostically unfavorable manifestation of later stage spreading of its invasive counterpart. We here briefly review the evolution of the IDC-P concept, the histological diagnostic criteria and differential diagnosis, the clinical significance, as well as recent molecular data of IDC-P.

Integrative analyses reveal a long noncoding RNA-mediated sponge regulatory network in prostate cancer

Mounting evidence suggests that long noncoding RNAs (lncRNAs) can function as microRNA sponges and compete for microRNA binding to protein-coding transcripts. However, the prevalence, functional significance and targets of lncRNA-mediated sponge regulation of cancer are mostly unknown. Here we identify a lncRNA-mediated sponge regulatory network that affects the expression of many protein-coding prostate cancer driver genes, by integrating analysis of sequence features and gene expression profiles of both lncRNAs and protein-coding genes in tumours. We confirm the tumour-suppressive function of two lncRNAs (TUG1 and CTB-89H12.4) and their regulation of PTEN expression in prostate cancer. Surprisingly, one of the two lncRNAs, TUG1, was previously known for its function in polycomb repressive complex 2 (PRC2)-mediated transcriptional regulation, suggesting its sub-cellular localization-dependent function. Our findings not only suggest an important role of lncRNA-mediated sponge regulation in cancer, but also underscore the critical influence of cytoplasmic localization on the efficacy of a sponge lncRNA.

Long non-coding RNAs (lncRNA; >200 base pair nucleic acids with little protein-coding capacity) are emerging as potentially important regulators of oncogenesis. Here the authors show tumour suppressive lncRNA sponge function for the protein products of prostate cancer driver genes.

Histopathological features of intra-ductal carcinoma of prostatic and high grade prostatic intraepithelialneoplasia and correlation with PTEN and P63

BACKGROUND

The main morphologic differential diagnosis of intra-ductal carcinoma of prostate (IDC-P) is high grade prostatic intraepithelialneoplasia (HGPIN). Since IDC-P, unlike PIN, was strongly correlated with aggressive prostate cancer, differentiation of these is too necessary. So we evaluated immunohistopathological patterns and the prognostic factors of IDC-P and HGPIN, in radical prostatectomy samples.

METHODS

We evaluated 250 radical prostatectomy and detected 210 cases of prostatic adenocarcinoma without IDC-P foci, 40 cases with adenocarcinoma concomitant IDC-P, and 40 cases HGPIN; therefore, we evaluated immunohistopathological criteria in these groups. Data were analyzed using SPSS and P-value <0.05 was considered as the statistical significant level.

RESULTS

PSA level was significantly higher in IDC-P compared with non-IDC-P patients (15.7 ± 3.1 vs. 10.2 ± 4.3, P = 0.041). All pathological and morphologic features, also invasions factors were higher in IDC-P compared to non-IDC-P groups (P < 0.001). P63 was positive expressed in all IDC-P and HGPIN specimen. PTEN protein was diffusely expressed in the cytoplasm of all HGPIN but in 4 (11.1%) of IDC-P. PTEN and P63 were negative in adenocarcinoma foci.

CONCLUSION

We found that IDC-P had a unique histoclinical feature and was strongly associated with poor prognostic factors. Diagnosis and report of IDC-P should be considered in all prostate specimens. Also, we recommend PTEN IHC application for differentiated IDC-P from HGPIN in biopsies.

Premalignancy in Prostate Cancer: Rethinking What we Know

High-grade prostatic intraepithelial neoplasia (PIN) has been accepted as the main precursor lesion to invasive adenocarcinoma of the prostate, and this is likely to be the case. However, in an unknown number of cases, lesions fulfilling the diagnostic criteria for high-grade PIN may actually represent intra-acinar or intraductal spread of invasive carcinoma. Intriguingly, this possibility would not contradict many of the findings of previous epidemiologic studies linking high-grade PIN to carcinoma or molecular pathologic studies showing similar genomic (e.g., TMPRSS2-ERG gene fusion) as well as epigenomic and molecular phenotypic alterations between high-grade PIN and carcinoma. Also, this possibility would be consistent with previous anatomic studies in prostate specimens linking high-grade PIN and carcinoma in autopsy and other whole prostate specimens. In addition, if some cases meeting morphologic criteria for PIN actually represent intra-acinar spread of invasive carcinoma, this could be an important potential confounder of the interpretation of past clinical trials enrolling patients presumed to be without carcinoma, who are at high risk of invasive carcinoma. Thus, in order to reduce possible bias in future study/trial designs, novel molecular pathology approaches are needed to decipher when an apparent PIN lesion may be intra-acinar/intra-ductal spread of an invasive cancer and when it truly represents a precursor state. Similar approaches are needed for lesions known as intraductal carcinoma to facilitate better classification of them as true intra-ductal/acinar spread on one hand or as precursor high-grade PIN (cribriform type) on the other hand; a number of such molecular approaches (e.g., coevaluating TMPRSS-ERG fusion and PTEN loss) are already showing excellent promise. Cancer Prev Res; 9(8); 648-56. ©2016 AACR.

Intraductal Carcinoma of the Prostate: Morphologic Features, Differential Diagnoses, Significance, and Reporting Practices

The differential diagnosis for atypical cribriform lesions of the prostate has become increasingly complex and includes intraductal carcinoma of the prostate, high-grade prostatic intraepithelial neoplasia, and atypical intraductal proliferations. In this review, we summarize the morphologic and molecular features and significance of intraductal carcinoma of the prostate. We also summarize our institution's strategy for reporting and treatment recommendations for intraductal carcinoma of the prostate.

Oncogene-triggered suppression of DNA repair leads to DNA instability in cancer

DNA instability is an important contributor to cancer development. Previously, defects in the chromosome segregation and excessive DNA double strand breaks due to the replication or oxidative stresses were implicated in DNA instability in cancer. Here, we demonstrate that DNA instability can directly result from the oncogene-induced senescence signaling. Expression of the activated form of Her2 oncogene, NeuT, in immortalized breast epithelial cells led to downregulation of the major DNA repair factor histone H2AX and a number of other components of the HR and NHEJ double strand DNA breaks repair pathways. H2AX expression was regulated at the transcriptional level via a senescence pathway involving p21-mediated regulation of CDK and Rb1. The p21-dependent downregulation of H2AX was seen both in cell culture and the MMTV-neu mouse model of Her2-positive breast cancer. Importantly, downregulation of H2AX upon Her2/NeuT expression impaired repair of double strand DNA breaks. This impairment resulted in both increased DNA instability in the form of somatic copy number alterations, and in increased sensitivity to the chemotherapeutic drug doxorubicin. Overall, these findings indicate that the Her2/NeuT oncogene signaling directly potentiates DNA instability and increases sensitivity to DNA damaging treatments.

MicroRNA-375 plays a dual role in prostate carcinogenesis

Background

Prostate cancer (PCa), a highly incident and heterogeneous malignancy, mostly affects men from developed countries. Increased knowledge of the biological mechanisms underlying PCa onset and progression are critical for improved clinical management. MicroRNAs (miRNAs) deregulation is common in human cancers, and understanding how it impacts in PCa is of major importance. MiRNAs are mostly downregulated in cancer, although some are overexpressed, playing a critical role in tumor initiation and progression. We aimed to identify miRNAs overexpressed in PCa and subsequently determine its impact in tumorigenesis.

Results

MicroRNA expression profiling in primary PCa and morphological normal prostate (MNPT) tissues identified 17 miRNAs significantly overexpressed in PCa. Expression of three miRNAs, not previously associated with PCa, was subsequently assessed in large independent sets of primary tumors, in which miR-182 and miR-375 were validated, but not miR-32. Significantly higher expression levels of miR-375 were depicted in patients with higher Gleason score and more advanced pathological stage, as well as with regional lymph nodes metastases. Forced expression of miR-375 in PC-3 cells, which display the lowest miR-375 levels among PCa cell lines, increased apoptosis and reduced invasion ability and cell viability. Intriguingly, in 22Rv1 cells, which displayed the highest miR-375 expression, knockdown experiments also attenuated the malignant phenotype. Gene ontology analysis implicated miR-375 in several key pathways deregulated in PCa, including cell cycle and cell differentiation. Moreover, CCND2 was identified as putative miR-375 target in PCa, confirmed by luciferase assay.

Conclusions

A dual role for miR-375 in prostate cancer progression is suggested, highlighting the importance of cellular context on microRNA targeting.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0076-2) contains supplementary material, which is available to authorized users.

Loss of PLZF expression in prostate cancer by immunohistochemistry correlates with tumor aggressiveness and metastasis

PLZF is a transcription repressor, which plays a critical role in development, spermatogenesis and oncogenesis. Down-regulation of PLZF has been found in various tumor cell lines. There has been virtually no tissue study on the expression of PLZF in prostate cancer (PCa). PCa is a heterogeneous disease, most of which are indolent and non-lethal. Currently there are no biomarkers that distinguish indolent from aggressive PCa; therefore there is an urgent need for such markers to provide clinical decision support. This study aimed to investigate the expression of PLZF by immunohistochemistry in different grade as well as metastatic PCa and to correlate the alteration of PLZF expression with PCa aggressiveness. We studied a total of 83 primary PCa from biopsies, 43 metastatic PCa and 8 paired primary and metastatic PCa from radical prostatectomies with lymph node dissection. Our results demonstrated that PLZF was strongly expressed in almost all (~100%) benign luminal cells (n=77) and low grade (Gleason pattern 3) PCa (n=70) and weak or absent (100%) in basal cells (n=70). Decreased or lost expression of PLZF was evidenced in 26% of high-grade (Gleason 4 and 5) primary PCa (n=70) and 84% metastatic PCa (n=43). The primary high grade PCa in the prostatectomies shared similar PLZF loss/decrease and histomorphology to that of paired parallel lymph node metastases. These data demonstrated that down-regulation of PLZF is an important molecular process for tumor progression and loss of PLZF expression detected by routine immunohistochemistry is a promising and valuable biomarker for PCa aggressiveness and metastasis in the personalized care of PCa.

Utility of PTEN and ERG immunostaining for distinguishing high-grade PIN from intraductal carcinoma of the prostate on needle biopsy

Intraductal carcinoma of the prostate and high-grade prostatic intraepithelial neoplasia (PIN) have markedly different implications for patient care but can be difficult to distinguish in needle biopsies. In radical prostatectomies, we demonstrated that PTEN and ERG immunostaining may be helpful to resolve this differential diagnosis. Here, we tested whether these markers are diagnostically useful in the needle biopsy setting. Separate or combined immunostains were applied to biopsies containing morphologically identified intraductal carcinoma, PIN, or borderline intraductal proliferations more concerning than PIN but falling short of morphologic criteria for intraductal carcinoma. Intraductal carcinoma occurring with concurrent invasive tumor showed the highest rate of PTEN loss, with 76% (38/50) lacking PTEN and 58% (29/50) expressing ERG. Of biopsies containing isolated intraductal carcinoma, 61% (20/33) showed PTEN loss and 30% (10/33) expressed ERG. Of the borderline intraductal proliferations, 52% (11/21) showed PTEN loss and 27% (4/15) expressed ERG. Of the borderline cases with PTEN loss, 64% (7/11) had carcinoma in a subsequent needle biopsy specimen, compared with 50% (5/10) of PTEN-intact cases. In contrast, none of the PIN cases showed PTEN loss or ERG expression (0/19). On needle biopsy, PTEN loss is common in morphologically identified intraductal carcinoma yet is very rare in high-grade PIN. Borderline intraductal proliferations, especially those with PTEN loss, have a high rate of carcinoma on resampling. If confirmed in larger prospective studies, these results suggest that PTEN and ERG immunostaining may provide a useful ancillary assay to distinguish intraductal carcinoma from high-grade PIN in this setting.

Exploring prostate cancer genome reveals simultaneous losses of PTEN, FAS and PAPSS2 in patients with PSA recurrence after radical prostatectomy

The multifocal nature of prostate cancer (PCa) creates a challenge to patients' outcome prediction and their clinical management. An approach that scrutinizes every cancer focus is needed in order to generate a comprehensive evaluation of the disease, and by correlating to patients' clinico-pathological information, specific prognostic biomarker can be identified. Our study utilized the Affymetrix SNP 6.0 Genome-wide assay to investigate forty-three fresh frozen PCa tissue foci from twenty-three patients. With a long clinical follow-up period that ranged from 2.0-9.7 (mean 5.4) years, copy number variation (CNV) data was evaluated for association with patients' PSA status during follow-up. From our results, the loss of unique genes on 10q23.31 and 10q23.2-10q23.31 were identified to be significantly associated to PSA recurrence (p < 0.05). The implication of PTEN and FAS loss (10q23.31) support previous reports due to their critical roles in prostate carcinogenesis. Furthermore, we hypothesize that the PAPSS2 gene (10q23.2-10q23.31) may be functionally relevant in post-operative PSA recurrence because of its reported role in androgen biosynthesis. It is suggestive that the loss of the susceptible region on chromosome 10q, which implicates PTEN, FAS and PAPSS2 may serve as genetic predictors of PSA recurrence after radical prostatectomy.

Intraductal carcinoma of the prostate: a comprehensive and updated review

Intraductal carcinoma of the prostate is characterized by prostatic carcinoma cells growing within ducts and/or acini. These tumors are usually associated with a high-grade Gleason score, large tumor volume and advanced stage. Intraductal carcinoma of the prostate is also a well-known adverse independent prognostic factor regardless of treatment. Recent studies have shown that intraductal carcinoma of the prostate is a distinctive disease entity that is different from invasive prostate carcinoma, which is generally invasive. Although the Gleason score does not consider intraductal carcinoma of the prostate, some cribriform prostate carcinomas graded as pattern 4 could be considered as intraductal carcinomas. The definition of intraductal carcinoma of the prostate is not unified, because it can occur with or without invasive prostate carcinoma. Furthermore, diagnosis of intraductal carcinoma of the prostate without invasive prostate carcinoma by needle biopsy is crucial, but is a rare event. Differential diagnosis of intraductal carcinoma of the prostate includes several pathologies. This is especially true for high-grade prostatic intraepithelial neoplasia, although its distinction is not always straightforward. The present review discusses the concept of intraductal carcinoma of the prostate, and also describes its morphological characteristics, molecular features and clinical outcome. Given the current state of knowledge, the presence of intraductal carcinoma of the prostate should be evaluated and documented correctly in both radical prostatectomy and needle biopsy, and the clinical implications should be taken into consideration during treatment and follow up.