Preneoplasia in the prostate gland with emphasis on high grade prostatic intraepithelial neoplasia

Chronic exposure to microcystin-LR increases the risk of prostate cancer and induces malignant transformation of human prostate epithelial cells

Microcystins-LR (MC-LR) acts as a possible carcinogen for humans and causes a serious risk to public environmental health. The current study aimed to evaluate the interaction between MC-LR exposure and prostate cancer development and elucidate the underlying mechanism. In this study, mice were exposed to MC-LR at various doses for 180 days. MC-LR was able to induce the progression of prostatic intraepithelial neoplasia (PIN) and microinvasion. Furthermore, MC-LR notably increased angiogenesis and susceptibility to prostate cancer in vivo. In vitro, over 25 weeks of MC-LR exposure, normal human prostate epithelial (RWPE-1) cells increased secretion of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and colony formation, features typical for cancer cells. These MC-LR-transformed prostate epithelial cells displayed increased expression of forkhead box M1 (FOXM1) and cyclooxygenase-2 (COX-2); abrogation of FOXM1 or COX-2 activity by specific inhibitors could abolish the invasion and migration of MC-LR-treated cells. In conclusion, we have provided compelling evidence demonstrating the induction of a malignant phenotype in human prostate epithelial cells and the in vivo development of prostate cancer by exposure to MC-LR, which might be a potential tumor promoter in the progression of prostate cancer.

Clinical significance of the De Ritis ratio for detecting prostate cancer in a repeat prostate biopsy

Purpose

We evaluated factors predicting a positive repeat biopsy result in patients with an initial negative prostate biopsy result.

Materials and Methods

This study included 124 patients in whom prostate cancer (PCa) was not detected in the initial transrectal ultrasound-guided prostate biopsy and who underwent repeat biopsy from January 2011 to December 2017. Patients without PCa in both initial and repeat prostate biopsies were designated as group 1 (n=82), and those in whom PCa was detected on a repeat prostate biopsy were designated as group 2 (n=42). Among group 2 patients, 6 had insignificant PCa according to the Epstein criteria and were combined with group 1 patients to make up group A (n=88). Patients with significant PCa were categorized as group B (n=36). We compared clinicopathologic characteristics between the groups.

Results

Multivariate analysis showed that age (p=0.018) and detection of atypical small acinar proliferation (ASAP) or ≥3 cores of high-grade prostatic intraepithelial neoplasia (HGPIN) (p=0.011) on the initial biopsy were predictive factors for a positive result on a repeat biopsy. When we compared group A and group B, age (p=0.004) and the De Ritis ratio (p=0.024) were significantly higher in group B in the multivariate analysis.

Conclusions

Age and the detection of ASAP or ≥3 cores of HGPIN on the initial biopsy were associated with detection of PCa on a repeat biopsy. Age and the De Ritis ratio were found to be predictive factors for the detection of clinically significant PCa on a repeat biopsy.

Essential role of JunD in cell proliferation is mediated via MYC signaling in prostate cancer cells

JunD, a member of the AP-1 family, is essential for cell proliferation in prostate cancer (PCa) cells. We recently demonstrated that JunD knock-down (KD) in PCa cells results in cell cycle arrest in G1-phase concomitant with a decrease in cyclin D1, Ki67, and c-MYC, but an increase in p21 levels. Furthermore, the over-expression of JunD significantly increased proliferation suggesting JunD regulation of genes required for cell cycle progression. Here, employing gene expression profiling, quantitative proteomics, and validation approaches, we demonstrate that JunD KD is associated with distinct gene and protein expression patterns. Comparative integrative analysis by Ingenuity Pathway Analysis (IPA) identified 1) cell cycle control/regulation as the top canonical pathway whose members exhibited a significant decrease in their expression following JunD KD including PRDX3, PEA15, KIF2C, and CDK2, and 2) JunD dependent genes are associated with cell proliferation, with MYC as the critical downstream regulator. Conversely, JunD over-expression induced the expression of the above genes including c-MYC. We conclude that JunD is a crucial regulator of cell cycle progression and inhibiting its target genes may be an effective approach to block prostate carcinogenesis.

Case - Foamy, high-grade prostatic intraepithelial neoplasia: A false positive for prostate cancer on multiparametric magnetic resonance imaging?

The introduction of multiparametric magnetic resonance imaging (mpMRI) of the prostate, and specifically the introduction of diffusion-weighted imaging (DWI), has significantly impacted the diagnosis of prostate cancer and the management of clinically localized prostate cancer. Indeed, its localizing ability has now opened up opportunities to target focal lesions in partial gland ablation therapy as a treatment option for localized prostate cancer. With negative predictive rates of mpMRI approaching 90% in certain series,1 mpMRI has the ability to discriminate between clinically significant intermediate-to-high-risk prostate cancer and low-risk indolent disease. However, false positives can occur. In recent studies, lesions observed on MRI were classified as tumour on targeted biopsy in 47.6% to over 94% for tumours larger than 0.5 ml in volume.2,3 Herein, we present a case of a rare non-cancer, but putatively pre-malignant prostatic histology that was found on biopsies directed at a category 5 Prostate Imaging Reporting and Data System (PIRADS) v2 lesion.

Atypical Small Acinar Proliferation and High Grade Prostatic Intraepithelial Neoplasia: Should We Be Concerned? An Observational Cohort Study with a Minimum Follow-Up of 3 Years

Introduction

Atypical small acinar proliferation (ASAP) and high grade prostatic intraepithelial neoplasia (HGPIN) are considered precancerous. We aimed to measure the rate of repeat biopsy and adenocarcinoma in patients with ASAP and HGPIN and identify any clinico-pathologic parameters at diagnosis of ASAP/HGPIN that are predictive of adenocarcinoma.

Materials and Methods

Patients with a diagnosis of ASAP/HGPIN with no previous or concomitant cancer were identified. Prostate specific antigen (PSA) and magnetic resonance imaging (MRI) changes were monitored. Re-biopsy was at clinician discretion.

Results

Nineteen were diagnosed with ASAP and 17 with HGPIN. Seven with ASAP (37%) and 6 with HGPIN (35%) underwent re-biopsy. Three (16%) with ASAP and 5 with HGPIN (29%) were diagnosed with adenocarcinoma. The difference in cancer detection rates between ASAP and HGPIN was not significant (p = 0.35). Five (14%) in total required definitive therapy for adenocarcinoma. Twenty-three (64%) did not undergo repeat biopsy. Parameters at diagnosis of HGPIN and ASAP, including PSA, prostate volume and PSA density, were compared between the cancer and non-cancer cohorts with none found to be predictive of adenocarcinoma.

Conclusion

By monitoring PSA and MRI changes, we managed to spare re-biopsy in two-thirds of patients. Further evaluation is necessary to characterize a surveillance protocol in these populations.

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.

Focal Signet Ring Cell High-Grade Prostatic Intraepithelial Neoplasia on Needle Biopsy

Signet ring cell prostatic intraepithelial neoplasia is a rare speculated variant of high-grade prostatic intraepithelial neoplasia (HGPIN). Here, we present a free-standing and isolated signet ring cell HGPIN that was not associated with invasive carcinoma on needle biopsy and demonstrated the existence of this type of HGPIN variant. The differentiation between HGPIN and intraductal carcinoma of prostate is also discussed.

Feature-based analysis of mouse prostatic intraepithelial neoplasia in histological tissue sections

This paper describes work presented at the Nordic Symposium on Digital Pathology 2015, in Linköping, Sweden. Prostatic intraepithelial neoplasia (PIN) represents premalignant tissue involving epithelial growth confined in the lumen of prostatic acini. In the attempts to understand oncogenesis in the human prostate, early neoplastic changes can be modeled in the mouse with genetic manipulation of certain tumor suppressor genes or oncogenes. As with many early pathological changes, the PIN lesions in the mouse prostate are macroscopically small, but microscopically spanning areas often larger than single high magnification focus fields in microscopy. This poses a challenge to utilize full potential of the data acquired in histological specimens. We use whole prostates fixed in molecular fixative PAXgene™, embedded in paraffin, sectioned through and stained with H&E. To visualize and analyze the microscopic information spanning whole mouse PIN (mPIN) lesions, we utilize automated whole slide scanning and stacked sections through the tissue. The region of interests is masked, and the masked areas are processed using a cascade of automated image analysis steps. The images are normalized in color space, after which exclusion of secretion areas and feature extraction is performed. Machine learning is utilized to build a model of early PIN lesions for determining the probability for histological changes based on the calculated features. We performed a feature-based analysis to mPIN lesions. First, a quantitative representation of over 100 features was built, including several features representing pathological changes in PIN, especially describing the spatial growth pattern of lesions in the prostate tissue. Furthermore, we built a classification model, which is able to align PIN lesions corresponding to grading by visual inspection to more advanced and mild lesions. The classifier allowed both determining the probability of early histological changes for uncategorized tissue samples and interpretation of the model parameters. Here, we develop quantitative image analysis pipeline to describe morphological changes in histological images. Even subtle changes in mPIN lesion characteristics can be described with feature analysis and machine learning. Constructing and using multidimensional feature data to represent histological changes enables richer analysis and interpretation of early pathological lesions.

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.

Inverted (hobnail) high-grade prostatic intraepithelial neoplasia and invasive inverted pattern

High-grade prostatic intraepithelial neoplasia (HGPIN) is considered to be an important precursor for prostatic adenocarcinoma. The present study aimed to investigate the histological features of the uncommon inverted (hobnail) pattern of HGPIN in transrectal ultrasonographic (TRUS) prostatic needle biopsies from 13 cases. These 13 diagnosed cases of inverted HGPIN were identified out of a total of 2,034 TRUS biopsies (0.63%), obtained from patients suspected to have prostate cancer. The hobnail pattern is comprised of secretory cell nuclei, which are histologically localized at the luminal surface of the prostate gland, rather than the periphery, and exhibit reverse polarity. Histological examinations were performed and the results demonstrated that 5 of the 13 cases exhibited pure inverted histology, while HGPIN was observed to be histologically associated with other patterns in the remaining 8 patients. In addition, an association with adenocarcinoma was identified in 7 of the 13 cases. All 7 carcinomas accompanied by inverted HGPIN were conventional acinar adenocarcinoma cases; of note, for these 7 cases, the Gleason score was 7 for each. One acinar adenocarcinoma case accompanying inverted HGPIN demonstrated hobnail characteristics in large areas of the invasive component. It was observed that nuclei were proliferated in the invasive cribriform glands, which was comparable to that of inverted HGPIN, and were located on the cytoplasmic luminal surface; a similar morphology was also observed in individual glands. In conclusion, the results of the present study suggested that the hobnail HGPIN pattern may be of diagnostic importance due to its high association with adenocarcinoma and the high Gleason scores in the accompanying carcinomas.

Gleason Score 6 - Prostate Cancer or Benign Variant?

The leading motivation behind wanting to call a 'malignant' prostate lesion 'benign' is the evidence of indolent prostate cancer that is not associated with a fatal outcome and in part makes therapeutic measures such as surgery and radiotherapy appear like overtreatment for some or possibly the majority of such patients. The present article reviews the definitions of 'precancerous lesion' and 'cancer' from a histopathologic point of view as the basis and gold standard for diagnosis. It is clear that with the 2 modifications implemented since its first publication, the Gleason score as the grading system for prostate cancer has shifted towards a low malignant subgroup diagnosed as Gleason 6. The recommendation of the International Society of Urological Pathology to change the Gleason score to a 5-tiered system, starting with grade group 1, is presented here, and may help doctor-patient communication especially in the active surveillance setting.

Exploiting altered patterns of choline kinase-alpha expression on human prostate tissue to prognosticate prostate cancer

AIMS

Malignant transformation results in overexpression of choline-kinase (CHK) and altered choline metabolism, which is potentially detectable by immunohistochemistry (IHC). We investigated the utility of CHK-alpha (CHKA) IHC as a complement to current diagnostic investigation of prostate cancer by analysing expression patterns in normal (no evidence of malignancy) and malignant human prostate tissue samples.

METHODS

As an initial validation, paraffin-embedded prostatectomy specimen blocks with both normal and malignant prostate tissue were analysed for CHKA protein and mRNA expression by western blot and quantitative reverse transcriptase PCR (qRT-PCR), respectively. Subsequently, 100 paraffin-embedded malignant prostate tumour and 25 normal prostate cores were stained for both Ki67 (labelling-index: LI) and CHKA expression.

RESULTS

The validity of CHKA-antibody was verified using CHKA-transfected cells and siRNA knockdown. Immunoblotting of tissues showed good resolution of CHKA protein in malignant prostate, verifying use of the antibody for IHC. There was minimal qRT-PCR detectable CHKA mRNA in normal tissue, and conversely high expression in malignant prostate tissues. IHC of normal prostate cores showed mild (intensity) CHKA expression in only 28% (7/25) of samples with no Ki67 expression. In contrast, CHKA was expressed in all malignant prostate cores along with characteristically low proliferation (median 2% Ki67-LI; range 1-17%). Stratification of survival according to CHK intensity showed a trend towards lower progression-free survival with CHK score of 3.

CONCLUSIONS

Increased expression of CHKA, detectable by IHC, is seen in malignant lesions. This relatively simple cost-effective technique (IHC) could complement current diagnostic procedures for prostate cancer and, therefore, warrants further investigation.

Androgen-deprivation therapy-induced aggressive prostate cancer with neuroendocrine differentiation

Most prostate cancers (PCas) are classified as acinar type (conventional) adenocarcinoma which are composed of tumor cells with luminal differentiation including the expression of androgen receptor (AR) and prostate-specific antigen (PSA). There are also scattered neuroendocrine (NE) cells in every case of adenocarcinoma. The NE cells are quiesecent, do not express AR or PSA, and their function remains unclear. We have demonstrated that IL8-CXCR2-P53 pathway provides a growth-inhibitory signal and keeps the NE cells in benign prostate and adenocarcinoma quiescent. Interestingly, some patients with a history of adenocarcinoma recur with small cell neuroendocrine carcinoma (SCNC) after hormonal therapy, and such tumors are composed of pure NE cells that are highly proliferative and aggressive, due to P53 mutation and inactivation of the IL8-CXCR2-P53 pathway. The incidence of SCNC will likely increase due to the widespread use of novel drugs that further inhibit AR function or intratumoral androgen synthesis. A phase II trial has demonstrated that platinum-based chemotherapy may be useful for such therapy-induced tumors.

Vitamin D Deficiency Adds an Element of Risk to Insulin Resistance in Colorectal Neoplasms

BACKGROUND

Both insulin resistance (IR) and vitamin D deficiency (VitDdef) have been suggested as risk factors for colorectal neoplasms (CRNs). However, the associations between the two with regard to CRNs are unclear.

AIMS

To determine whether IR is a risk factor for CRNs and whether VitDdef confers an additive risk of CRNs.

METHODS

Colonoscopy-naïve asymptomatic women undergoing a routine health screening program were analyzed. IR was defined as homeostatic model assessment of IR >3 and VitDdef set as <20 ng/mL. Multivariable logistic regression was performed between women with and without CRNs, matched for age and body mass index, to investigate associations with CRNs in IR, VitDdef, and VitDdef combined with IR.

RESULTS

We analyzed 216 women with CRNs and 216 without CRNs. A significant association was found between IR and CRNs (OR 1.838, 95 % CI 1.029-3.285, P = 0.040) but not with VitDdef. IR conferred a higher risk in advanced CRNs (OR 3.244, 95 % CI 1.588-6.631, P = 0.001) than CRNs. When VitDdef was combined with IR, risks of both CRNs and advanced CRNs increased (OR 2.131, 95 % CI 1.077-4.216, P = 0.030 and OR 4.438, 95 % CI 2.058-9.571, P < 0.001, respectively).

CONCLUSIONS

IR increases the risk of CRNs, and a combination of IR and VitDdef further increases this risk. As both VitDdef and IR are modifiable risk factors, such associations may have important clinical implications in the prevention of CRNs.

A panel of DNA methylation markers reveals extensive methylation in histologically benign prostate biopsy cores from cancer patients

BACKGROUND

Men with a negative first prostate biopsy will undergo one or more additional biopsies if they remain at high suspicion of prostate cancer. To date, there are no diagnostic tests capable of identifying patients at risk for a positive diagnosis with the predictive power needed to eliminate unnecessary repeat biopsies. Efforts to develop clinical tests using the epigenetic signature of cores recovered from first biopsies have been limited to a few markers and lack the sensitivity and specificity needed for widespread clinical adoption.

METHODS

We developed methylation-specific quantitative polymerase chain reaction assays for a panel of 24 markers that are preferentially methylated in prostate cancer. We modified the bisulfite conversion conditions to allow the integration of the methylation information from multiple markers. We determined the methylation status of the 24 markers in 213 prostate biopsy cores from 104 patients, 37 prostate cancer patients and 67 controls. We performed logistic regression on combinations of markers as well as the entire panel of 24 markers to identify the best candidates for a diagnostic test.

RESULTS

The marker panel differentiated between cancer cores and benign cores from non-cancer patients with 100% sensitivity and 97% specificity. Furthermore, the panel detected significant methylation in benign cores from prostate cancer patients that was not present in controls. Using methylation of 5 out of 24 to define a cancer case, the analysis of a single benign biopsy core identified 62% of prostate cancer patients undergoing repeat biopsies. ROC curve analysis showed that markers commonly methylated in benign cores from cancer patients are the best candidates for a diagnostic test. The results suggest that 5 to 10 markers will be needed to achieve optimal predictive power.

CONCLUSIONS

This study shows that epigenetic field effects differ significantly between cancer patients and controls. Their detection in benign biopsy cores can form the basis of diagnostic tests to identify patients in need of repeat biopsies, reducing the cost of continued PCA screening by up to 40%. They could also be used to identify prostate cancer patients with low grade disease who are likely candidates for active surveillance or focal therapy.

[Benign mimickers of the prostate cancer. Diagnostic challenges]

The diagnosis of prostate cancer (PCa), especially limited adenocarcinoma on needle biopsy, is often challenging. Before making diagnosis of PCa, it is prudent for the pathologist to consider different benign patterns that may lead to a false positive interpretation. Histoanatomic structures such as seminal vesicles, Cowper's glands and paraganglia along with hyperplasia, atrophy with its different patterns and adenosis may generate difficulties in differential diagnosis. Furthermore, inflammatory processes and post-treatment changes may cause problems. The above entities can in some instances simulate low-grade and less commonly high grade PCa. Knowledge of these patterns and application of appropriate immunohistochemistry will lead the pathologist to a correct diagnosis.