p53 Predictive Value for pT1-2 N0 Disease at Radical Cystectomy

Non-coding RNA transcripts, incredible modulators of cisplatin chemo-resistance in bladder cancer through operating a broad spectrum of cellular processes and signaling mechanism

Bladder cancer (BC) is a highly frequent neoplasm in correlation with significant rate of morbidity, mortality, and cost. The onset of BC is predominantly triggered by environmental and/or occupational exposures to carcinogens, such as tobacco. There are two distinct pathways by which BC can be developed, including non-muscle-invasive papillary tumors (NMIBC) and non-papillary (or solid) muscle-invasive tumors (MIBC). The Cancer Genome Atlas project has further recognized key genetic drivers of MIBC along with its subtypes with particular properties and therapeutic responses; nonetheless, NMIBC is the predominant BC presentation among the suffering individuals. Radical cystoprostatectomy, radiotherapy, and chemotherapy have been verified to be the common therapeutic interventions in metastatic tumors, among which chemotherapeutics are more conventionally utilized. Although multiple chemo drugs have been broadly administered for BC treatment, cisplatin is reportedly the most effective chemo drug against the corresponding malignancy. Notwithstanding, tumor recurrence is usually occurred following the consumption of cisplatin regimens, particularly due to the progression of chemo-resistant trait. In this framework, non-coding RNAs (ncRNAs), as abundant RNA transcripts arise from the human genome, are introduced to serve as crucial contributors to tumor expansion and cisplatin chemo-resistance in bladder neoplasm. In the current review, we first investigated the best-known ncRNAs, i.e. microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), correlated with cisplatin chemo-resistance in BC cells and tissues. We noticed that these ncRNAs could mediate the BC-related cisplatin-resistant phenotype through diverse cellular processes and signaling mechanisms, reviewed here. Eventually, diagnostic and prognostic potential of ncRNAs, as well as their therapeutic capabilities were highlighted in regard to BC management.

p53 as Exemplar Next-Generation Immunohistochemical Marker: A Molecularly Informed, Pattern-Based Approach, Methodological Considerations, and Pan-Cancer Diagnostic Applications

This review is based on a webinar I presented for the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) in February 2022. It is intended that all ISIMM webinars will ultimately be published in AIMM as review articles. This work is also dedicated to Clive Taylor, who has deeply impacted my career. It presents a molecularly informed, pattern-based approach to p53 immunohistochemistry interpretation, methodological considerations (ie, antibody selection, optimization, validation, controls, and external quality assessment), and pan-cancer diagnostic applications, including those drawn from gastrointestinal, genitourinary, gynecological, neuroendocrine, hematologic, and neuropathology. It intends to prove the thesis statement that p53 is an exemplar next-generation immunohistochemical marker "born" ahead of its time.

Impact of intravesical instillation of a novel biological response modifier (P-MAPA) on progress of non-muscle invasive bladder cancer treatment in a rat model

This work describes the effects of immunotherapy with Protein Aggregate Magnesium-Ammonium Phospholinoleate-Palmitoleate Anhydride in the treatment of non-muscle invasive bladder cancer in an animal model. NMIBC was induced by treating female Fischer 344 rats with N-methyl-N-nitrosourea. After treatment with MNU, the rats were distributed into four experimental groups: Control (without MNU) group, MNU (cancer) group, MNU-BCG (Bacillus Calmette-Guerin) group, and MNU-P-MAPA group. P-MAPA intravesical treatment was more effective in histopathological recovery from cancer state in relation to BCG treatment. Western blot assays showed an increase in the protein levels of c-Myc, COUP-TFII, and wild-type p53 in P-MAPA-treated rats in relation to BCG-treated rats. In addition, rats treated with P-MAPA intravesical immunotherapy showed the highest BAX protein levels and the lowest proliferation/apoptotic ratio in relation to BCG-treated rats, pointing out a preponderance of apoptosis. P-MAPA intravesical treatment increased the wild-type p53 levels and enhanced c-Myc/COUP-TFII-induced apoptosis mediated by p53. These alterations were fundamental for histopathological recovery from cancer and for suppress abnormal cell proliferation. This action of P-MAPA on apoptotic pathways may represent a new strategy for treating NMIBC.

Prognostic Value of Vascular-Expressed PSMA and CD248 in Urothelial Carcinoma of the Bladder

Background

Urothelial carcinoma of the bladder (UCB) is a common cancer of the urinary system. Despite substantial improvements in available treatment options, the survival outcome of patients with advanced UCB is unsatisfactory. Therefore, it is necessary to identify new prognostic biomarkers for monitoring and therapy guidance of UCB. In recent years, prostate-specific membrane antigen (PSMA) and CD248 have been identified promising candidate bio7markers.

Methods

In this study, we first examined PSMA and CD248 expression in tissues from 124 patients with UCB using immunohistochemical and immunofluorescent staining. We then analyzed the association between the expression of the two biomarkers and other clinicopathological features and prognosis. Finally, we performed bioinformatic analysis of CD248 and FOLH 1 (PSMA) using the TCGA-BLCA dataset to explore the underlying mechanism of PSMA and CD248 in the progression of UCB.

Results

Among the 124 cases, PSMA and CD248 were confirmed to be expressed in tumor-associated vessels. Vascular PSMA and CD248 expression levels were associated significantly with several deteriorated clinicopathological features. Furthermore, using univariate and multivariate Cox analyses, high vascular PSMA and CD248 expression levels were observed to be associated significantly with poor prognosis in patients with UCB. As risk factors, both PSMA and CD248 expression showed good performance to predict prognosis. Furthermore, combining these vascular molecules with other clinical risk factors generated a risk score that could promote predictive performance. Bioinformatic analysis showed that both PSMA and CD248 might contribute to angiogenesis and promote further progression of UCB.

Conclusion

Both PSMA and CD248 are specifically expressed in the tumor-associated vasculature of UCB. These two molecules might be used as novel prognostic biomarkers and vascular therapeutic targets for UCB.

Perioperative Systemic Treatment for Muscle-Invasive Bladder Cancer: Current Evidence and Future Perspectives

Radical cystectomy is the primary treatment for muscle-invasive bladder cancer; however, approximately 50% of patients develop metastatic disease within 2 years of diagnosis, which results in dismal prognosis. Therefore, systemic treatment is important to improve the prognosis of muscle-invasive bladder cancer. Currently, several guidelines recommend cisplatin-based neoadjuvant chemotherapy before radical cystectomy, and adjuvant chemotherapy is recommended in patients who have not received neoadjuvant chemotherapy. Immune checkpoint inhibitors have recently become the standard treatment option for metastatic urothelial carcinoma. Owing to their clinical benefits, several immune checkpoint inhibitors, with or without other agents (including other immunotherapy, cytotoxic chemotherapy, and emerging agents such as antibody drug conjugates), are being extensively investigated in perioperative settings. Several studies for perioperative immunotherapy have shown that immune checkpoint inhibitors have promising efficacy with relatively low toxicity, and have explored the predictive molecular biomarkers. Herein, we review the current evidence and discuss the future perspectives of perioperative systemic treatment for muscle-invasive bladder cancer.

Non coding RNAs as the critical factors in chemo resistance of bladder tumor cells

BACKGROUND

Bladder cancer (BCa) is the ninth frequent and 13th leading cause of cancer related deaths in the world which is mainly observed among men. There is a declining mortality rates in developed countries. Although, the majority of BCa patients present Non-Muscle-Invasive Bladder Cancer (NMIBC) tumors, only 30% of patients suffer from muscle invasion and distant metastases. Radical cystoprostatectomy, radiation, and chemotherapy have proven to be efficient in metastatic tumors. However, tumor relapse is observed in a noticeable ratio of patients following the chemotherapeutic treatment. Non-coding RNAs (ncRNAs) are important factors during tumor progression and chemo resistance which can be used as diagnostic and prognostic biomarkers of BCa.

MAIN BODY

In present review we summarized all of the lncRNAs and miRNAs associated with chemotherapeutic resistance in bladder tumor cells.

CONCLUSIONS

This review paves the way of introducing a prognostic panel of ncRNAs for the BCa patients which can be useful to select a proper drug based on the lncRNA profiles of patients to reduce the cytotoxic effects of chemotherapy in such patients.

Diagnostic and Prognostic Potential of Biomarkers CYFRA 21.1, ERCC1, p53, FGFR3 and TATI in Bladder Cancers

The high occurrence of bladder cancer and its tendency to recur in combination with a lifelong surveillance make the treatment of superficial bladder cancer one of the most expensive and time-consuming. Moreover, carcinoma in situ often leads to muscle invasion with an unfavorable prognosis. Currently, invasive methods including cystoscopy and cytology remain a gold standard. The aim of this study was to explore urine-based biomarkers to find the one with the best specificity and sensitivity, which would allow optimizing the treatment plan. In this review, we sum up the current knowledge about Cytokeratin fragments (CYFRA 21.1), Excision Repair Cross-Complementation 1 (ERCC1), Tumour Protein p53 (Tp53), Fibroblast Growth Factor Receptor 3 (FGFR3), Tumor-Associated Trypsin Inhibitor (TATI) and their potential applications in clinical practice.

Molecular markers in bladder cancer

Purpose

Use of molecular markers in urine, tissue or blood offers potential opportunities to improve understanding of bladder cancer biology which may help identify disease earlier, risk stratify patients, improve prediction of outcomes or help target therapy.

Methods

A review of the published literature was performed, without restriction of time.

Results

Despite the fast-growing literature about the topic and the approval of several urinary biomarkers for use in clinical practice, they have not reached the level of evidence for widespread utilization. Biomarkers could be used in different clinical scenarios, mainly to overcome the limitations of current diagnostic, predictive, and prognostic tools. They have been evaluated to detect bladder cancer in asymptomatic populations or those with hematuria and in surveillance of disease as adjuncts to cystoscopy. There is also a potential role as prognosticators of disease recurrence, progression and survival both in patients with non-invasive cancers and in those with advanced disease. Finally, they promise to be helpful in predicting the response to local and/or systemic chemotherapy and/or immunotherapy.

Conclusions

To date, due to the lack of high-quality prospective trials, the level of evidence provided by the current literature remains low and, therefore, the potential of biomarkers exceeds utilization in clinical practice.

Molecular Prognostication in Bladder Cancer

Clinical outcomes for patients with bladder cancer have largely remained unchanged over the last three decades despite improvements in surgical techniques, perioperative therapies, and postoperative management. Current management still heavily relies on pathologic staging that does not always reflect an individual patient's risk. The genesis and progression of bladder cancer is now increasingly recognized as being a result of alterations in several pathways that affect the cell cycle, apoptosis, cellular signaling, gene regulation, immune modulation, angiogenesis, and tumor cell invasion. Multiplexed assessment of biomarkers associated with alterations in these pathways offers novel insights into tumor behavior while identifying panels that are capable of reproducibly predicting patient outcomes. Future management of bladder cancer will likely incorporate such prognostic molecular models for risk stratification and treatment personalization.

The Rho GTPase signalling pathway in urothelial carcinoma

Urothelial carcinoma remains a clinical challenge: non-muscle-invasive disease has a high rate of recurrence and risk of progression, and outcomes for patients with advanced disease are poor, owing to a lack of effective systemic therapies. The Rho GTPase family of enzymes was first identified >30 years ago and contains >20 members, which are divided into eight subfamilies: Cdc42, Rac, Rho, RhoUV, RhoBTB, RhoDF, RhoH, and Rnd. Rho GTPases are molecular on-off switches, which are increasingly being understood to have a critical role in a number of cellular processes, including cell migration, cell polarity, cell adhesion, cell cycle progression, and regulation of the cytoskeleton. This switch is an evolutionarily conserved system in which GTPases alternate between GDP-bound (inactive) and GTP-bound (active) forms. The activities of these Rho GTPases are many, context-dependent, and regulated by a number of proteins that are being progressively elucidated. Aberrations of the Rho GTPase signalling pathways have been implicated in various malignancies, including urothelial carcinoma, and understanding of the role of Rho GTPases in these diseases is increasing. This signalling pathway has the potential for therapeutic targeting in urothelial carcinoma. Research in this area is nascent, and much work is necessary before current laboratory-based research can be translated into the clinic.

Immunohistochemistry Biomarkers in Nonmuscle Invasive Bladder Cancer

Bladder cancer (BCa) is the most frequent urinary tract neoplasm. BCa results in significant mortality when the disease presents as muscle invasive. Around 75% to 80% of patients present with nonmuscle invasive bladder cancer (NMIBC), but recurrence and progression are significant issues, compelling current guidelines to recommend long-term surveillance. There is therefore an urgent and unmet need to identify and validate accurate biomarkers for the detection of disease recurrence to improve quality of life for the patients and reduce costs for health care providers, while maintaining or improving current outcomes. In this review, 38 publications on immunohistochemistry prognostic biomarkers, that were studied may be related in nonmuscle invasive bladder cancer, have been analyzed. The studies were organized according to the evaluated marker and their findings. It was demonstrated that the combination of independent complementary biomarkers could allow a more accurate prognosis than an isolated marker. Biomarkers, including p53, Ki-67, and CK20, with classic and prognostic factors with recurrence and novel markers such as EN2 may provide a more accurate prediction of outcome compared with any single marker, improving risk stratification and clinical management of patients with BCa.

Urinary Bladder Cancer: Biomarkers and Target Therapy, New Era for More Attention

Currently, bladder cancer (BCa) evaluation depends mainly on traditional clinicopathological parameters encompassing tumor stage and grade, which will not reflect the behavior of the disease. Diverse molecular alterations are responsible for the heterogeneous course. The differences in molecular pathogenesis between non-invasive BCa and invasive BCa have been recognized. Molecular biomarkers are promising to predict progression and survival. The management of advanced BCa remains somewhat primitive in comparison with other more common malignancies. This topic will discuss the molecular pathways, biomarkers and potential targets that may improve the outcome in BCa.

Increased toll-like receptors and p53 levels regulate apoptosis and angiogenesis in non-muscle invasive bladder cancer: mechanism of action of P-MAPA biological response modifier

BACKGROUND

The new modalities for treating patients with non-muscle invasive bladder cancer (NMIBC) for whom BCG (Bacillus Calmette-Guerin) has failed or is contraindicated are recently increasing due to the development of new drugs. Although agents like mitomycin C and BCG are routinely used, there is a need for more potent and/or less-toxic agents. In this scenario, a new perspective is represented by P-MAPA (Protein Aggregate Magnesium-Ammonium Phospholinoleate-Palmitoleate Anhydride), developed by Farmabrasilis (non-profit research network). This study detailed and characterized the mechanisms of action of P-MAPA based on activation of mediators of Toll-like Receptors (TLRs) 2 and 4 signaling pathways and p53 in regulating angiogenesis and apoptosis in an animal model of NMIBC, as well as, compared these mechanisms with BCG treatment.

RESULTS

Our results demonstrated the activation of the immune system by BCG (MyD88-dependent pathway) resulted in increased inflammatory cytokines. However, P-MAPA intravesical immunotherapy led to distinct activation of TLRs 2 and 4-mediated innate immune system, resulting in increased interferons signaling pathway (TRIF-dependent pathway), which was more effective in the NMIBC treatment. Interferon signaling pathway activation induced by P-MAPA led to increase of iNOS protein levels, resulting in apoptosis and histopathological recovery. Additionally, P-MAPA immunotherapy increased wild-type p53 protein levels. The increased wild-type p53 protein levels were fundamental to NO-induced apoptosis and the up-regulation of BAX. Furthermore, interferon signaling pathway induction and increased p53 protein levels by P-MAPA led to important antitumor effects, not only suppressing abnormal cell proliferation, but also by preventing continuous expansion of tumor mass through suppression of angiogenesis, which was characterized by decreased VEGF and increased endostatin protein levels.

CONCLUSIONS

Thus, P-MAPA immunotherapy could be considered an important therapeutic strategy for NMIBC, as well as, opens a new perspective for treatment of patients that are refractory or resistant to BCG intravesical therapy.

Managing noninvasive recurrences after definitive treatment for muscle-invasive bladder cancer or high-grade upper tract urothelial carcinoma

PURPOSE OF REVIEW

Approximately 50% of patients with muscle invasive urothelial carcinoma will relapse with distant recurrence. Though rates of local recurrence after definitive therapy have improved, management remains a challenge. In this review, treatment strategies for this cohort are re-examined in an effort to enhance patient outcomes.

RECENT FINDINGS

Urothelial carcinoma continues to demonstrate high rates of recurrence and low rates of survival. Similarly to the treatment of primary urothelial cancer, treatment of recurrence focuses on cytology, stage, and clinical characteristics. Current areas of interest have focused on identification and causes/predictors of recurrence.

SUMMARY

Limited progress has been achieved in differentiating management of recurrent urothelial carcinoma from the treatment of primary urothelial carcinoma. However, there may be an increasing role for endoscopic and organ conserving therapies for carefully selected patients with recurrent noninvasive urothelial carcinoma. Identifying those at risk for early recurrence and early diagnosis of recurrence may be the most beneficial future strategies. The treatment regimen for noninvasive bladder recurrence after radical nephroureterectomy for upper tract urothelial carcinoma should include intravesical chemotherapy or Bacillus Calmette-Guerin to prevent further bladder recurrence or tumor progression. We do not advocate diversion sparing techniques for local recurrence after radical cystectomy. Metastasectomy for distant/metastatic urothelial carcinoma recurrence represents a promising area of future study.

Molecular substratification of bladder cancer: moving towards individualized patient management

Despite advances in surgical techniques, perioperative therapies and postoperative management, outcomes for patients with bladder cancer have largely remained unchanged. Current management of bladder cancer still relies on pathologic staging that does not always reflect the risk for an individual patient. Studies assessing molecular alterations in individual tumors are offering insights into the myriad of cellular pathways that are deregulated in bladder tumorigenesis and progression. Alterations in pathways involved in cell-cycle regulation, apoptosis, cell signaling, angiogenesis and tumor-cell invasion have been shown to influence disease behavior. High-throughput assays are now allowing multiplexed assessment of biomarker alterations, thereby enabling characterization of novel molecular subtypes of bladder cancer. Such approaches have also been used for discovery and validation of robust prognostic molecular signatures. The future of bladder cancer management will rely on the use of validated multimarker panels for risk stratification, optimal surgical management, and theranostic strategies to identify and target specific alterations in individual tumors.

Prospective evaluation of a molecular marker panel for prediction of recurrence and cancer-specific survival after radical cystectomy

BACKGROUND

Retrospective studies demonstrated that cell cycle-related and proliferation biomarkers add information to standard pathologic tumor features after radical cystectomy (RC). There are no prospective studies validating the clinical utility of markers in bladder cancer.

OBJECTIVE

To prospectively determine whether a panel of biomarkers could identify patients with urothelial carcinoma of the bladder (UCB) who were likely to experience disease recurrence or mortality.

DESIGN, SETTING, AND PARTICIPANTS

Between January 2007 and January 2012, every patient with high-grade bladder cancer, including 216 patients treated with RC and lymphadenectomy, underwent immunohistochemical staining for tumor protein p53 (Tp53); cyclin-dependent kinase inhibitor 1A (p21, Cip1) (CDKN1A); cyclin-dependent kinase inhibitor 1B (p27, Kip1); antigen identified by monoclonal antibody Ki-67 (MKI67); and cyclin E1.

INTERVENTION

Every patient underwent RC and lymphadenectomy, and marker staining.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox regression analyses tested the ability of the number of altered biomarkers to predict recurrence or cancer-specific mortality (CSM).

RESULTS AND LIMITATIONS

Pathologic stage among the study population was pT0 (5%), pT1 (35%), pT2 (19%), pT3 (29%), and pT4 (13%); lymphovascular invasion (LVI) was seen in 34%. The median number of removed lymph nodes was 23, and 60 patients had lymph node involvement (LNI). Median follow-up was 20 mo. Expression of p53, p21, p27, cyclin E1, and Ki-67 were altered in 54%, 26%, 46%, 15%, and 75% patients, respectively. In univariable analyses, pT stage, LNI, LVI, perioperative chemotherapy (CTx), margin status, and number of altered biomarkers predicted disease recurrence. In a multivariable model adjusting for pathologic stage, margins, LNI, and adjuvant CTx, only LVI and number of altered biomarkers were independent predictors of recurrence and CSM. The concordance index of a baseline model predicting CSM (including pathologic stage, margins, LVI, LNI, and adjuvant CTx) was 80% and improved to 83% with addition of the number of altered markers.

CONCLUSIONS

Molecular markers improve the prediction of recurrence and CSM after RC. They may identify patients who might benefit from additional treatments and closer surveillance after cystectomy.

Bladder cancer: a simple model becomes complex

Bladder cancer is one of the most frequent malignancies in developed countries and it is also characterized by a high number of recurrences. Despite this, several authors in the past reported that only two altered molecular pathways may genetically explain all cases of bladder cancer: one involving the FGFR3 gene, and the other involving the TP53 gene. Mutations in any of these two genes are usually predictive of the malignancy final outcome. This cancer may also be further classified as low-grade tumors, which is always papillary and in most cases superficial, and high-grade tumors, not necessarily papillary and often invasive. This simple way of considering this pathology has strongly changed in the last few years, with the development of genome-wide studies on expression profiling and the discovery of small non-coding RNA affecting gene expression. An easy search in the OMIM (On-line Mendelian Inheritance in Man) database using "bladder cancer" as a query reveals that genes in some way connected to this pathology are approximately 150, and some authors report that altered gene expression (up- or down-regulation) in this disease may involve up to 500 coding sequences for low-grade tumors and up to 2300 for high-grade tumors. In many clinical cases, mutations inside the coding sequences of the above mentioned two genes were not found, but their expression changed; this indicates that also epigenetic modifications may play an important role in its development. Indeed, several reports were published about genome-wide methylation in these neoplastic tissues, and an increasing number of small non-coding RNA are either up- or down-regulated in bladder cancer, indicating that impaired gene expression may also pass through these metabolic pathways. Taken together, these data reveal that bladder cancer is far to be considered a simple model of malignancy. In the present review, we summarize recent progress in the genome-wide analysis of bladder cancer, and analyse non-genetic, genetic and epigenetic factors causing extensive gene mis-regulation in malignant cells.

MDM2 SNP309 promoter polymorphism and p53 mutations in urinary bladder carcinoma stage T1

Background

Urinary bladder carcinoma stage T1 is an unpredictable disease that in some cases has a good prognosis with only local or no recurrence, but in others can appear as a more aggressive tumor with progression to more advanced stages. The aim here was to investigate stage T1 tumors regarding MDM2 promoter SNP309 polymorphism, mutations in the p53 gene, and expression of p53 and p16 measured by immunohistochemistry, and subsequently relate these changes to tumor recurrence and progression. We examined a cohort of patients with primary stage T1 urothelial carcinoma of the bladder and their tumors.

Methods

After re-evaluation of the original slides and exclusions, the study population comprised 141 patients, all with primary stage T1 urothelial carcinoma of the bladder. The hospital records were screened for clinical parameters and information concerning presence of histologically proven recurrence and progression. The paraffin-embedded tumor material was evaluated by immunohistochemistry. Any mutations found in the p53 gene were studied by single-strand conformation analysis and Sanger sequencing. The MDM2 SNP309 polymorphism was investigated by pyrosequencing. Multivariate analyses concerning association with prognosis were performed, and Kaplan-Meier analysis was conducted for a combination of changes and time to progression.

Results

Of the 141 patients, 82 had at least one MDM2 SNP309 G allele, and 53 had a mutation in the p53 gene, but neither of those anomalies was associated with a worse prognosis. A mutation in the p53 gene was associated with immunohistochemically visualized p53 protein expression at a cut-off value of 50%. In the group with p53 mutation Kaplan-Meier analysis showed higher rate of progression and shorter time to progression in patients with immunohistochemically abnormal p16 expression compared to them with normal p16 expression (p = 0.038).

Conclusions

MDM2 SNP309 promoter polymorphism and mutations in p53 were not associated with worse prognosis in this cohort of patients with primary stage T1 urinary bladder carcinoma. However, patients with abnormal p16 expression and a mutated p53 gene had a higher rate of and a shorter time to progression, and p53 gene mutation was associated with an abnormal immunohistochemistry for p53 at a cut-off of 50%.

Novel molecular targets for the therapy of urothelial carcinoma

INTRODUCTION

First-line platinum-based combinations are active in locally advanced and metastatic urothelial carcinoma; however, long-term outcomes including disease-specific and overall survival remain suboptimal. In addition, approximately 40 - 50% of patients with advanced urothelial carcinoma have coexisting medical issues that preclude the use of cisplatin-based therapy. Improvements in our understanding of the molecular mechanisms of urothelial tumorigenesis have led to first-generation clinical trials evaluating novel agents targeting molecular pathways. These are particularly relevant in regard to subpopulations. Novel trial designs warrant consideration to accelerate accrual.

AREAS COVERED

In this review, novel molecular targets for the therapy of urothelial carcinoma, as well as recently completed and ongoing clinical trials utilizing novel targeted agents, are discussed. A Medline search with key words, abstracts reported at national conferences on urothelial carcinoma and NCI clinical trial identifiers was used for this review.

EXPERT OPINION

Improved understanding of molecular biology has identified a number of new molecular targets, but there is a seeming absence of one dominant molecular driver for urothelial cancer. An adaptive and biomarker-derived strategy may be warranted. Clinical trials utilizing targeted agents are ongoing and results are awaited.

MiR-34a chemosensitizes bladder cancer cells to cisplatin treatment regardless of p53-Rb pathway status

MiR-34a is a downstream effector of p53 that has been shown to target several molecules associated with cell cycle and cell survival pathways. As alterations in these pathways are frequent in muscle invasive transitional cell carcinoma of the bladder (MI-TCC), for example mutation or loss of p53 and Rb, the goal of this study was to determine whether manipulation of miR-34a expression levels could abrogate the effect of these alterations and sensitize bladder cancer cells to chemotherapy. We demonstrate that transfection of T24, TCCSUP and 5637 with pre-miR-34a followed by cisplatin treatment results in a dramatic reduction in clonogenic potential and induction of senescence compared to treatment with cisplatin alone. Molecular analyses identified Cdk6 and sirtuin (SIRT)-1 as being targeted by miR-34a in MI-TCC cells, however, inhibition of Cdk6 and SIRT-1 was not as effective as pre-miR-34a in mediating chemosensitization. Analysis of 27 preneoadjuvant chemotherapy patient samples revealed many of the patients who subsequently did not respond to treatment (based on surgical resection postchemotherapy and 5-year survival data) express lower levels of miR-34a, however, a statistically significant difference between the responder and nonresponder groups was not observed (p = 0.1174). Analysis of eight sets of pre- and postneoadjuvant chemotherapy patient samples determined miR-34a expression increased postchemotherapy in only two of the eight patients. The combined data indicate that elevation of miR-34a expression levels before chemotherapy would be of benefit to MI-TCC patients, particularly in a setting of low miR-34a expression.

Immunohistochemical biomarkers for bladder cancer prognosis

Urothelial carcinoma of the bladder (UCB) is an especially complex and heterogeneous disease with a broad spectrum of histologic findings and potentially lethal behavior. Despite advances in surgical techniques, as well as intravesical and systemic therapies, up to 30% of patients with non-muscle-invasive UCB and 50% of patients with muscle-invasive UCB experience disease progression, recurrence, and eventual death. Standard prognostic features, such as pathologic stage and grade, have limited ability to predict the outcomes of this heterogeneous population. Current risk-stratification algorithms using clinical and pathologic parameters are limited in their prognostic ability. Molecular medicine holds the promise that clinical outcomes will be improved by more accurate prognostication and directing therapy towards the mechanisms and targets associated with the growth of an individual patient's tumor. Immunohistochemical analysis of biomarker expression has provided insight into the molecular pathogenesis of UCB and offers the potential for improving clinical decision making. Numerous candidate immunohistochemical biomarkers for patients with UCB have been identified, with those relating to the cell cycle and apoptosis/cell proliferation being the most extensively studied. The present review discusses the most promising immunohistochemical biomarkers. Special attention is paid to recent data from a multi-institutional collaboration that has implemented a regulated, phased biomarker discovery and validation pathway. Because UCB tumorigenesis and progression is a process involving multiple genetic and epigenetic alterations, multiple biomarkers need to be integrated into a prognostic signature to accurately predict outcomes. There is no doubt that biomarkers will eventually guide our clinical decision making regarding follow-up scheduling and treatment choice.

Molecular diagnostics in urologic malignancies: a work in progress

CONTEXT

Molecular diagnostic applications are now an integral part of the management algorithms of several solid tumors, such as breast, colon, and lung. In stark contrast, the current clinical management of urologic malignancies is lagging behind. Clinically robust molecular tests that can identify patients who are more likely to respond to a given targeted agent or even those in need of a more aggressive treatment based on well-validated molecular prognosticators are still lacking. Several promising biomarkers for detection, prognosis, and targeted therapeutics are being evaluated.

OBJECTIVE

To discuss candidate biomarkers that may soon make the transition to clinical assay for patients in urologic oncology.

DATA SOURCES

Selected original articles published in the PubMed service of the US National Library of Medicine.

CONCLUSIONS

Recent understanding of the complex molecular alterations involved in the development and progression of urologic malignancies is yielding novel diagnostic and prognostic molecular tools and opening the doors for experimental targeted therapies in these prevalent, frequently lethal solid tumors.

Primary adenocarcinoma of the urinary bladder: value of cell cycle biomarkers

Primary adenocarcinomas of the urinary bladder are uncommon, and the molecular pathways are currently not well defined. In this study, we assessed the association between biologic markers and clinicopathologic characteristics in a cohort of 21 patients with primary urinary bladder adenocarcinoma. Immunohistochemical staining for cell cycle-specific markers, including p53, p21, p27, Ki-67, and cyclin E, were performed on sections of a tissue microarray construct. The tumors were high grade in 12 (57%) and pT2 or higher in 18 (86%); lymph nodes were involved in 6 cases (29%); and there was pathologic evidence of schistosomiasis in 14 (67%). The best prognostic combination of markers was combined alterations in p27 and Ki-67 and was associated with stage (P = .012), grade (P = .005), DNA ploidy (P = .005), and lymph node involvement (P = .04). Stage, lymph node involvement, combined alterations of p27 and Ki-67, and combined alterations of all 5 biomarkers were associated with increased probability of disease recurrence and cancer-specific mortality (P < .05).

Molecular genetics of bladder cancer: Emerging mechanisms of tumor initiation and progression

Urothelial cancer has served as one of the most important sources of information about the mutational events that underlie the development of human solid malignancies. Although "field effects" that affect the entire bladder mucosa appear to initiate disease, tumors develop along 2 distinct biological "tracks" that present vastly different challenges for clinical management. Recent whole genome methodologies have facilitated even more rapid progress in the identification of the molecular mechanisms involved in bladder cancer initiation and progression. Specifically, whole organ mapping combined with high resolution, high throughput SNP analyses have identified a novel class of candidate tumor suppressors ("forerunner genes") that localize near more familiar tumor suppressors but are disrupted at an earlier stage of cancer development. Furthermore, whole genome comparative genomic hybridization (CGH) and mRNA expression profiling have demonstrated that the 2 major subtypes of urothelial cancer (papillary/superficial and non-papillary/muscle-invasive) are truly distinct molecular entities, and in recent work our group has discovered that muscle-invasive tumors express molecular markers characteristic of a developmental process known as "epithelial-to-mesenchymal transition" (EMT). Emerging evidence indicates that urothelial cancers contain subpopulations of tumor-initiating cells ("cancer stem cells") but the phenotypes of these cells in different tumors are heterogeneous, raising questions about whether or not the 2 major subtypes of cancer share a common precursor. This review will provide an overview of these new insights and discuss priorities for future investigation.

The effect of age on bladder cancer incidence, prognosis and therapy

Age is now widely accepted as the single greatest risk factor for developing urothelial carcinoma of the bladder (UCB). The aim of this article is to assess the incidence, prognosis and therapy of UCB in the elderly. Using MEDLINE, we performed a search of the literature between January 1966 and July 2009. The link between aging and cancer is more complex than the simple passage of time; certain genes may be activated while others may be suppressed with advancing age. Treatments for nonmuscle-invasive UCB are generally well-tolerated by the elderly. However, several studies have demonstrated a lower response rate to intravesical immunotherapy in the elderly. While elderly patients have a higher rate of perioperative complication and mortality after radical cystectomy, the difference is too small and insufficient to avoid radical cystectomy in these patients. Similarly, in certain selected cases, centers of excellence report similar complication rates in elderly patients, regardless of the type of urinary diversion. The optimal application of perioperative chemotherapy is dependent on the degree of compromise of the organ systems through comorbid conditions and physiologic deterioration. Restrictive case selection and proactive postoperative rehabilitation are important for elderly patients to obtain good results. Age alone does not preclude optimal treatment for patients with aggressive UCB. Radical surgery, urinary diversion and systemic chemotherapy are feasible, safe and efficacious in the treatment of adequately selected elderly UCB patients. It is imperative that healthcare practitioners and researchers from disparate disciplines collectively focus their efforts to appropriately meet the multifaceted medical and psychosocial needs of the elderly.

Bladder cancer: can we move beyond chemotherapy?

Since the advent of cisplatin-based chemotherapy, cytotoxic combination chemotherapy remains the mainstay of treatment for locally advanced and metastatic urothelial malignancies. The current paradigm of combining novel agents with cytotoxic chemotherapy without any understanding of the underlying biology of urothelial cancer has limited the impact of developing novel agents for this disease. Current research investigating the biology of bladder cancer, including the role of p53, EMT, EGFR-related pathways, and anti-angiogenic pathways, may potentially impact the future development of novel agents targeting urothelial malignancies. Additionally, the use of novel gene therapy to mediate enhanced interferon expression in the bladder using adenoviral vectors, and enhancing tumor recognition strategies using the immune system with vaccines and anti-CTLA4 antibodies, are of interest. It is hoped that through these efforts we may soon move beyond the traditional cytotoxic chemotherapy paradigm, developing combinations that are more active and less toxic for all patients with urothelial cancer.