Clinical applications of recent molecular advances in urologic malignancies: no longer chasing a "mirage"?

Clear cell renal cell carcinoma with cystic component similar to multilocular cystic renal neoplasm of low malignant potential: a rare pattern of cyst-dependent progression from multilocular cystic renal neoplasm of low malignant potential

BACKGROUND

For clear cell renal cell carcinoma (ccRCC) with cystic component similar to multilocular cystic renal neoplasm of low malignant potential (MCRN-LMP) and solid low-grade component simultaneously, we propose the designation "ccRCC with cystic component similar to MCRN-LMP" and to study the relationship between MCRN-LMP and it.

METHODS

Twelve cases of MCRN-LMP and 33 cases of ccRCC with cystic component similar to MCRN-LMP were collected from 3,265 consecutive RCCs to compare them in clinicopathological features, immunohistochemical findings (PAX8, CA-IX, CK7, Vimentin, CD10, P504s, TFE3, 34βE12) and prognosis.

RESULTS

There was no significant difference in age, sex ratio, tumor size, treatment, grade and stage between them (P > 0.05). All ccRCCs with cystic component similar to MCRN-LMP coexisted with MCRN-LMP and solid low-grade ccRCCs, and MCRN-LMP component ranged from 20 to 90% (median, 59%). The positive ratio of CK7 and 34βE12 in MCRN-LMPs and ccRCCs' cystic parts was significantly higher than that in ccRCCs' solid parts, but the positive ratio of CD10 in MCRN-LMPs and ccRCCs' cystic parts was significantly lower than that in ccRCCs' solid parts (P < 0.05). There was no significant difference of all immunohistochemistry profiles between MCRN-LMPs and ccRCCs' cystic parts (P > 0.05). No patient developed recurrence or metastasis.

CONCLUSIONS

MCRN-LMP and ccRCC with cystic component similar to MCRN-LMP have similarity and homology in clinicopathological features, immunohistochemical findings and prognosis, and form a low-grade spectrum with indolent or low malignant potential behavior. The ccRCC with cystic component similar to MCRN-LMP may be a rare pattern of cyst-dependent progression from MCRN-LMP.

Untangling the association between environmental endocrine disruptive chemicals and the etiology of male genitourinary cancers

Endocrine disrupting chemicals disrupt normal physiological function of endogenous hormones, their receptors, and signaling pathways of the endocrine system. Most endocrine disrupting chemicals exhibit estrogen/androgen agonistic and antagonistic activities that impinge upon hormone receptors and related pathways. Humans are exposed to endocrine disrupting chemicals through food, water and air, affecting the synthesis, release, transport, metabolism, binding, function and elimination of naturally occurring hormones. The urogenital organs function as sources of steroid hormones, are targeted end organs, and participate within systemic feedback loops within the endocrine system. The effects of endocrine disruptors can ultimately alter cellular homeostasis leading to a broad range of health effects, including malignancy. Human cancer is characterized by uncontrolled cell proliferation, mechanisms opposing cell-death, development of immortality, induction of angiogenesis, and promotion of invasion/metastasis. While hormonal malignancies of the male genitourinary organs are the second most common types of cancer, the molecular effects of endocrine disrupting chemicals in hormone-driven cancers has yet to be fully explored. In this commentary, we examine the molecular evidence for the involvement of endocrine disrupting chemicals in the genesis and progression of hormone-driven cancers in the prostate, testes, and bladder. We also report on challenges that have to be overcome to drive our understanding of these chemicals and explore the potential avenues of discovery that could ultimately allow the development of tools to prevent cancer in populations where exposure is inevitable.

Incidence and distribution of UroSEEK gene panel in a multi-institutional cohort of bladder urothelial carcinoma

Noninvasive approaches for early detection of bladder cancer are actively being investigated. We recently developed a urine- based molecular assay for the detection and surveillance of bladder neoplasms (UroSEEK). UroSEEK is designed to detect alterations in 11 genes that include most common genetic alterations in bladder cancer. In this study, we analyzed 527 cases, including 373 noninvasive and 154 invasive urothelial carcinomas of bladder from transurethral resections or cystectomies performed at four institutions (1991-2016). Two different mutational analysis assays of a representative tumor area were performed: first, a singleplex PCR assay for evaluation of the TERT promoter region (TERTSeqS) and second, a multiplex PCR assay using primers designed to amplify regions of interest of 10 (FGFR3, PIK3CA, TP53, HRAS, KRAS, ERBB2, CDKN2A, MET, MLL, and VHL) genes (UroSeqS). Overall, 92% of all bladder tumors were positive for at least one genetic alteration in the UroSEEK panel. We found TERT promoter mutations in 77% of low-grade noninvasive papillary carcinomas, with a relatively lower incidence of 65% in high-grade noninvasive papillary carcinomas and carcinomas in situ; p = 0.017. Seventy-two percent of pT1 and 63% of muscle-invasive bladder tumors harbored TERT promoter mutations with g.1295228C>T alteration being the most common in all groups. FGFR3 and PIK3CA mutations were more frequent in low-grade noninvasive papillary carcinomas compared with high-grade noninvasive papillary carcinomas and carcinomas in situ (p < 0.0001), while the opposite was true for TP53 (p < 0.0001). Significantly higher rates of TP53 and CDKN2A mutation rates (p = 0.005 and 0.035, respectively) were encountered in muscle-invasive bladder tumors compared with those of pT1 stage. The overwhelming majority of all investigated tumors showed at least one mutation among UroSEEK assay genes, confirming the comprehensive coverage of the panel and supporting its potential utility as a noninvasive urine-based assay.

A Review of Urine Ancillary Tests in the Era of the Paris System

Aside from its diagnostic importance, urinary tract endoscopy is an uncomfortable, expensive, and time-consuming procedure. Patients with a history of urothelial carcinoma remain at an increased risk for recurrence and the development of de novo disease; most have had exposure to carcinogenic risk factors for decades prior to their first diagnosis that have bathed the entire urothelial tract. Consequently, monitoring these patients over their lifetime has made urothelial carcinoma one of the most expensive cancers for the US healthcare system. This expense has provided a financial incentive for academic and commercial groups to develop a test with a sufficient negative predictive value to reduce the frequency of surveillance procedures. Slide-based tests require a separate slide prepared from a split urine sample or from an additional urinary tract specimen. This process can place an additional burden on the laboratory due to changes in the workflow, especially if the split specimens need to be stored until a cytologic diagnosis is rendered (i.e., when used as a reflex test). Importantly, slide-based tests allow for the result to be directly correlated with cytomorphologic findings; however, these tests require the cells of interest to be present. Thus, slide-based tests suffer from the same sensitivity issues as urinary tract cytology. In contrast, slide-free tests do not require an additional slide to be prepared, and laboratory testing may be centralized to a core facility or performed on-site. Some tests detect the expression of altered or abnormally expressed subcellular material (proteins, DNA, etc.) in urothelial neoplasms, which are found in tumor cells and/or in the urine specimen when the proteins are either excreted or leaked from degenerating tumor cells. Slide-free tests may also be developed into point-of-care tests, meaning that the result may be available to the urologist but not to the cytopathologist. Since these proteins are often disassociated from the tumor cells that produce them, such tests may have a positive result even if tumor cells are absent in the tested specimen. Here we review critical concepts as well as several ancillary tests that have been developed for urinary tract specimens.

Prostate Cancer Disparities by Race and Ethnicity: From Nucleotide to Neighborhood

Prostate cancer (CaP) incidence, morbidity, and mortality rates vary substantially by race and ethnicity, with African American men experiencing among the highest CaP rates in the world. The causes of these disparities are multifactorial and complex, and likely involve differences in access to screening and treatment, exposure to CaP risk factors, variation in genomic susceptibility, and other biological factors. To date, the proportion of CaP that can be explained by environmental exposures is small and differences in the role factors play by race or ethnicity is poorly understood. In the absence of additional data, it is likely that environmental factors do not contribute greatly to CaP disparities. In contrast, CaP has one of the highest heritabilities of all major cancers and many CaP susceptibility genes have been identified. Some CaP loci, including the risk loci found at chromosome 8q24, have consistent effects in all racial/ethnic groups studied to date. However, replication of many susceptibility loci across race or ethnicity remains limited. It is likely that inequities in health care access strongly influences CaP disparities. CaP is a disease with a complex multifactorial etiology, and therefore any approach attempting to address racial/ethnic disparities in CaP must consider the many sources that influence risk, outcomes, and disparities.

Non-invasive detection of urothelial cancer through the analysis of driver gene mutations and aneuploidy

Current non-invasive approaches for detection of urothelial cancers are suboptimal. We developed a test to detect urothelial neoplasms using DNA recovered from cells shed into urine. UroSEEK incorporates massive parallel sequencing assays for mutations in 11 genes and copy number changes on 39 chromosome arms. In 570 patients at risk for bladder cancer (BC), UroSEEK was positive in 83% of those who developed BC. Combined with cytology, UroSEEK detected 95% of patients who developed BC. Of 56 patients with upper tract urothelial cancer, 75% tested positive by UroSEEK, including 79% of those with non-invasive tumors. UroSEEK detected genetic abnormalities in 68% of urines obtained from BC patients under surveillance who demonstrated clinical evidence of recurrence. The advantages of UroSEEK over cytology were evident in low-grade BCs; UroSEEK detected 67% of cases whereas cytology detected none. These results establish the foundation for a new non-invasive approach for detection of urothelial cancer.

NF-κB p65 Overexpression Promotes Bladder Cancer Cell Migration via FBW7-Mediated Degradation of RhoGDIα Protein

BACKGROUND

Since invasive bladder cancer (BC) is one of the most lethal urological malignant tumors worldwide, understanding the molecular mechanisms that trigger the migration, invasion, and metastasis of BC has great significance in reducing the mortality of this disease. Although RelA/p65, a member of the NF-kappa B transcription factor family, has been reported to be upregulated in human BCs, its regulation of BC motility and mechanisms have not been explored yet.

METHODS

NF-κBp65 expression was evaluated in N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced high invasive BCs by immunohistochemistry staining and in human BC cell lines demonstrated by Western Blot. The effects of NF-κBp65 knockdown on BC cell migration and invasion, as well as its regulated RhoGDIα and FBW7, were also evaluated in T24T cells by using loss- and gain-function approaches. Moreover, the interaction of FBW7 with RhoGDIα was determined with immunoprecipitation assay, while critical role of ubiquitination of RhoGDIα by FBW7 was also demonstrated in the studies.

RESULTS

p65 protein was remarkably upregulated in the BBN-induced high invasive BCs and in human BC cell lines. We also observed that p65 overexpression promoted BC cell migration by inhibiting RhoGDIα expression. The regulatory effect of p65 on RhoGDIα expression is mediated by its upregulation of FBW7, which specifically interacted with RhoGDIα and promoted RhoGDIα ubiquitination and degradation. Mechanistic studies revealed that p65 stabilizing the E3 ligase FBW7 protein was mediated by its attenuating pten mRNA transcription.

CONCLUSIONS

We demonstrate that p65 overexpression inhibits pten mRNA transcription, which stabilizes the protein expression of ubiquitin E3 ligase FBW7, in turn increasing the ubiquitination and degradation of RhoGDIα protein and finally promoting human BC migration. The novel identification of p65/PTEN/FBW7/RhoGDIα axis provides a significant insight into understanding the nature of BC migration, further offering a new theoretical support for cancer therapy.

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.

Spectrum of genetic mutations in de novo PUNLMP of the urinary bladder

Our group and others have previously demonstrated the presence of TERT promoter mutations (TERT-mut) in 60-80% of urothelial carcinomas and some of their histologic variants. Five other genes have been frequently implicated in bladder cancer: FGRF3, TP53, PIK3CA, HRAS, and CDKN2A. In the current study, we sought to determine the prevalence of mutations in TERT and these five other genes in de novo papillary urothelial neoplasms of low malignant potential (PUNLMP) of the urinary bladder. A retrospective search of our archives for PUNLMP was performed and 30 de novo cases were identified and included in the study. We found mutations in TERT (TERT-mut) and FGFR3 (FGFR3-mut) to be the most common alterations in the cohort (63 and 60%, respectively). The majority of the TERT-mut-positive tumors (84%) had a g.1295228C > T alteration with the remaining tumors demonstrating g.1295250C > T. Approximately one fourth of tumors had TP53 mutations. These findings support the potential utility of a uniform genetic mutation panel to detect bladder cancers of various subtypes.

Prostate Cancer Genetics: Variation by Race, Ethnicity, and Geography

Prostate cancer rates vary substantially by race, ethnicity, and geography. These disparities can be explained by variation in access to screening and treatment, variation in exposure to prostate cancer risk factors, and variation in the underlying biology of prostate carcinogenesis (including genomic propensity of some groups to develop biologically aggressive disease). It is clear that access to screening and access to treatment are critical influencing factors of prostate cancer rates; yet, even among geographically diverse populations with similar access to care (eg, low- and medium-income countries), African descent men have higher prostate cancer rates and poorer prognosis. To date, the proportion of prostate cancer that can be explained by environmental exposures is small, and the effect of these factors across different racial, ethnic, or geographical populations is poorly understood. In contrast, prostate cancer has one of the highest heritabilities of all major cancers. Numerous genetic susceptibility markers have been identified from family-based studies, candidate gene association studies, and genome-wide association studies. Some prostate cancer loci, including the risk loci found at chromosome 8q24, have consistent effects in all groups studied to date. However, replication of many susceptibility loci across race, ethnicity, and geography remains limited, and additional studies in certain populations (particularly in men of African descent) are needed to better understand the underlying genetic basis of prostate cancer.

Tumors of the Testis: Morphologic Features and Molecular Alterations

This article reviews the most frequently encountered tumor of the testis; pure and mixed malignant testicular germ cell tumors (TGCT), with emphasis on adult (postpubertal) TGCTs and their differential diagnoses. We additionally review TGCT in the postchemotherapy setting, and findings to be integrated into the surgical pathology report, including staging of testicular tumors and other problematic issues. The clinical features, gross pathologic findings, key histologic features, common differential diagnoses, the use of immunohistochemistry, and molecular alterations in TGCTs are discussed.

Molecular Updates in Prostate Cancer

A wide array of molecular markers and genomic signatures, reviewed in this article, may soon be used as adjuncts to currently established screening strategies, prognostic parameters, and early detection markers. Markers of genetic susceptibility to PCA, recurrent epigenetic and genetic alterations, including ETS gene fusions, PTEN alterations, and urine-based early detection marker PCA3, are discussed. Impact of recent genome-wide assessment on our understanding of key pathways of PCA development and progression and their potential clinical implications are highlighted.

Molecular markers in bladder cancer: Novel research frontiers

Bladder cancer (BC) is a heterogeneous disease encompassing distinct biologic features that lead to extremely different clinical behaviors. In the last 20 years, great efforts have been made to predict disease outcome and response to treatment by developing risk assessment calculators based on multiple standard clinical-pathological factors, as well as by testing several molecular markers. Unfortunately, risk assessment calculators alone fail to accurately assess a single patient's prognosis and response to different treatment options. Several molecular markers easily assessable by routine immunohistochemical techniques hold promise for becoming widely available and cost-effective tools for a more reliable risk assessment, but none have yet entered routine clinical practice. Current research is therefore moving towards (i) identifying novel molecular markers; (ii) testing old and new markers in homogeneous patients' populations receiving homogeneous treatments; (iii) generating a multimarker panel that could be easily, and thus routinely, used in clinical practice; (iv) developing novel risk assessment tools, possibly combining standard clinical-pathological factors with molecular markers. This review analyses the emerging body of literature concerning novel biomarkers, ranging from genetic changes to altered expression of a huge variety of molecules, potentially involved in BC outcome and response to treatment. Findings suggest that some of these indicators, such as serum circulating tumor cells and tissue mitochondrial DNA, seem to be easily assessable and provide reliable information. Other markers, such as the phosphoinositide-3-kinase (PI3K)/AKT (serine-threonine kinase)/mTOR (mammalian target of rapamycin) pathway and epigenetic changes in DNA methylation seem to not only have prognostic/predictive value but also, most importantly, represent valuable therapeutic targets. Finally, there is increasing evidence that the development of novel risk assessment tools combining standard clinical-pathological factors with molecular markers represents a major quest in managing this poorly predictable disease.

To be an ally or an adversary in bladder cancer: the NF-κB story has not unfolded

Signaling and regulation of transcription factor nuclear factor-kappaB (NF-κB) has been an area of extensive research since its first discovery nearly three decades ago. Members of the NF-κB family have been reported to critically mediate a multitude of responses in normal cells. Therefore, it is not surprising that NF-κB function can go awry and result in pathological conditions including cancer. Despite its critical importance, the functional role of NF-κB has not received the same attention in cancers of all tissue types. In the case of cancer of the urinary bladder, which is the second most common urologic cancer, the involvement of NF-κB in the development of superficial or muscle invasive disease and during cancer recurrence is rudimentary at best. Nuclear expression of p65/RelA is seen in bladder cancer patients and has been found to negatively affect survival of patients with superficial and muscle invasive disease. Despite these observations, the exact mechanism of NF-κB upregulation and function remains unknown. Furthermore, the emergence of a tumor suppressive role for NF-κB in recent years suggests that the family may play the role of a double-edged sword in cancer, which remains unexplored in bladder cancer. The challenge now is to delineate the increasing complexity of this pathway in the development and progression of bladder cancer. Here, we review key aspects of the current knowledge of signaling and regulation by the NF-κB family focusing on its controversial role in cancer and highlight the importance of studying NF-κB in bladder cancer in particular.

Cyclin A1 expression predicts progression in pT1 urothelial carcinoma of bladder: a tissue microarray study of 149 patients treated by transurethral resection

AIMS

To evaluate the immunoexpression of cyclin A1 in pT1 urothelial carcinomas of the bladder (UC) from a cohort of patients treated by transurethral resection of the bladder (TURB), to determine its value in predicting tumour recurrence, tumour progression, or systemic metastases.

METHODS AND RESULTS

Five tissue microarrays (TMAS) were constructed from representative paraffin blocks of high-grade pT1 UC from 149 consecutive patients. Cyclin A1 immunoexpression was evaluated as the percentage of tumour cells with positive nuclear staining estimated at each TMA spot. The cutoff for cyclin A1 positivity was set at 10% of cells. Outcome variables included tumour recurrence and tumour progression as the primary endpoints. Cyclin A1 positivity was associated with tumour progression but not with tumour recurrence or the presence of adjacent carcinoma in situ in the biopsy. Also, patients with pT1b at biopsy and cyclin A1 expression showed higher progression rates than patients with pT1a at biopsy and without cyclin A1 expression, respectively. Combining pT1 stage at biopsy and cyclin A1 expression more accurately predicted tumour progression than pT1 stage at biopsy alone and cyclin A1 expression alone.

CONCLUSIONS

Cyclin A1 immunoexpression is of potential utility in predicting disease progression in patients with pT1 UC.

Molecular characteristics of urothelial neoplasms in children and young adults: a subset of tumors from young patients harbors chromosomal abnormalities but not FGFR3 or TP53 gene mutations

Urothelial neoplasms in children and young adult patients are rare and hypothesized to have a lower rate of recurrence and progression than those of older adults. Because of their rarity, data regarding molecular abnormalities in these tumors are limited. We studied molecular characteristics of urothelial neoplasms from patients under age 30 years using UroVysion fluorescence in situ hybridization (chromosomes 3, 7, 17, and 9p21) and DNA mutational analysis for the FGFR3 and TP53 genes. Seventeen tumors were identified in patients 6-26 years of age, including low-grade papillary urothelial carcinoma (n=10), high-grade papillary urothelial carcinoma (n=5), urothelial papilloma (n=1), and papillary urothelial neoplasm of low malignant potential (n=1). No tumor demonstrated mutation of FGFR3 or TP53. Chromosomal abnormalities were detected only in patients aged ≥19 years: two low-grade urothelial carcinomas had loss of 9p21 as a sole chromosomal abnormality and three high-grade urothelial carcinomas had other or multiple chromosomal abnormalities. Under age 19 years, no tumor showed molecular abnormalities with either method (five low-grade papillary urothelial carcinomas and one each of high-grade papillary urothelial carcinoma, papillary urothelial neoplasm of low malignant potential, and urothelial papilloma). Our results support the idea that mutations of the FGFR3 and TP53 genes are rare or absent in urothelial neoplasms of young patients. In contrast, chromosomal abnormalities detected by UroVysion fluorescence in situ hybridization are sometimes present in patients above 19-20 years of age. This finding supports the recently proposed hypothesis that an age of 19-20 years separates distinct molecular pathways of urothelial carcinogenesis.

ARID1A immunohistochemistry improves outcome prediction in invasive urothelial carcinoma of urinary bladder

AT-rich interactive domain 1A (ARID1A) is tumor suppressor gene that interacts with BRG1 adenosine triphosphatase to form a SWI/SNF chromatin remodeling protein complex. Inactivation of ARID1A has been described in several neoplasms, including epithelial ovarian and endometrial carcinomas, and has been correlated with prognosis. In the current study, ARID1A expression in urothelial carcinoma (UC) of the bladder and its association with clinicopathological parameters and outcome are addressed. Five tissue microarrays were constructed from 136 cystectomy specimens performed for UC at our institution. Nuclear ARID1A staining was evaluated using immunohistochemistry. An H-score was calculated as the sum of the products of intensity (0-3) multiplied by extent of expression (0%-100%). Average H-score per case was used for statistical analysis. ARID1A expression was categorized in low and high using Youden index to define the cut point. ARID1A expression significantly increased from normal to noninvasive UC to invasive UC. For both tumor progression and cancer death, Youden index yielded an H-score of 288 as the optimal cut point for ARID1A expression. Low ARID1A expression showed a tendency for lower risk of tumor progression and cancer mortality. Adding ARID1A expression to pathologic features offers a better model for predicting outcome than pathologic features alone. Low ARID1A expression was more frequently seen in earlier stage disease. There was a tendency for low ARID1A expression to predict better outcome. More importantly, the findings indicate that adding ARID1A expression to pathologic features increases the goodness of fit of the predictive model.

TERT promoter mutations occur early in urothelial neoplasia and are biomarkers of early disease and disease recurrence in urine

Activating mutations occur in the promoter of the telomerase reverse transcriptase (TERT) gene in 66% of muscle-invasive urothelial carcinomas. To explore their role in bladder cancer development and to assess their utility as urine markers for early detection, we sequenced the TERT promoter in 76 well-characterized papillary and flat noninvasive urothelial carcinomas, including 28 pTa low-grade transitional cell carcinomas (TCC), 31 pTa high-grade TCCs, and 17 pTis carcinoma in situ lesions. We also evaluated the sequence of the TERT promoter in a separate series of 14 early bladder neoplasms and matched follow-up urine samples to determine whether urine TERT status was an indicator of disease recurrence. A high rate of TERT promoter mutation was observed in both papillary and flat lesions, as well as in low- and high-grade noninvasive urothelial neoplasms (mean: 74%). In addition, among patients whose tumors harbored TERT promoter mutations, the same mutations were present in follow-up urines in seven of eight patients that recurred but in none of the six patients that did not recur (P < 0.001). TERT promoter mutations occur in both papillary and flat lesions, are the most frequent genetic alterations identified to date in noninvasive precursor lesions of the bladder, are detectable in urine, and seem to be strongly associated with bladder cancer recurrence. These provocative results suggest that TERT promoter mutations may offer a useful urinary biomarker for both early detection and monitoring of bladder neoplasia.