Prospective evaluation of p53 as a prognostic marker in T1 transitional cell carcinoma of the bladder

Biomarkers predicting oncological outcomes of high-risk non-muscle-invasive bladder cancer

INTRODUCTION

The European Organization for Research and Treatment of Cancer (EORTC) and the Spanish Urological Club for Oncological Treatment (CUETO) scoring systems show limited accuracy for the prediction of disease recurrence and progression of non-muscle-invasive bladder cancer (NMIBC). This aspect is even more relevant in the category of HR NMIBC. Biomarkers might potentially help to further categorize the outcomes of these patients. Therefore, we sought to review the evidence available on tissue-based, urinary, and serum biomarkers for the prediction of recurrence, progression, and survival in HR NMIBC.

EVIDENCE ACQUISITION

A systematic literature review without time restrictions was performed using PubMed/EMBASE, Web of Science, SCOPUS, and the Cochrane Libraries. The search was filtered for articles in the English, Italian, German, French, and Spanish languages, involving patients with more than 18 years of age. Relevant papers on tissue-based, serum and urinary biomarkers related to the prediction of oncological outcomes for high-risk bladder cancer patients were included in the analyses.

EVIDENCE SYNTHESIS

Overall, 71 studies were eligible for inclusion in this review. The majority of the investigations performed so far focused on immunohistochemical analyses on tumoral tissue. Overall, p53 was the most studied biomarker, but results regarding its prognostic and predictive role were contradictory. Ki67 seems to be a promising biomarker in the prediction of recurrence. Recently, PD-L1 has been associated with the prediction of recurrence free survival and of treatment-refractory disease. Markers developed un urine samples are focused on commercially available kits, which currently do not unequivocally show strongly superior levels of accuracy to cytology. However, they have demonstrated to be potentially helpful in the prediction of recurrence. Blood-based biomarkers represent an emerging reality with promising future applications.

CONCLUSIONS

Despite a long history of attempts to discover accurate biomarkers predicting oncological outcomes for HR NMIBC, contradictory or uncertain findings render the adoption of this ancillary techniques in clinical practice still unlikely. Future attempts should be directed to the development of prospective trials and the definition of standardized cut-off levels to render findings worthy of comparison.

The Role and Importance of Timely Radical Cystectomy for High-Risk Non-muscle-Invasive Bladder Cancer

Non-muscle-invasive bladder cancer accounts for the majority of incident bladder cancers but is a heterogeneous disease with variation in clinical presentation, course, and outcomes. Risk stratification techniques have attempted to identify those at highest risk of cancer recurrence and progression to help personalize and individualize treatment options. Radical cystectomy during the optimal window of curability could improve cancer outcomes; however, identifying the disease and patient characteristics as well as the correct timing to intervene remains difficult. We review the natural history of non-muscle-invasive bladder cancer, discuss different risk-stratification techniques and how they can help identify those most likely to benefit from radical treatment, and examine the evidence supporting the benefit of timely cystectomy.

Genomic characterization of high-risk non-muscle invasive bladder cancer

The genetic mechanisms associated with progression of high-risk non-muscle-invasive bladder cancer (HR-NMIBC) have not been described. We conducted selective next-generation sequencing (NGS) of HR-NMIBC and compared the genomic profiles of cancers that responded to intravesical therapy and those that progressed to muscle-invasive or advanced disease. DNA was extracted from paraffin-embedded sections from 25 HR-NMIBCs (22 with T1HG; 3 with TaHG with or without carcinoma in situ). Ten patients with HR-NMIBC developed progression (pT2+ or N+) (“progressors”). Fifteen patients had no progression (“non-progressors”). Tissue from 11 patients with metastatic bladder cancer (BC) were analyzed for comparison. We found no difference in frequency of mutations of TP53, PIK3CA, or KMT2D between the primary tumors of progressors compared to non-progressors and metastatic tumors. An increased frequency of deletions of CDKN2A/B was identified in tumors at progression (37%) compared to non-progressors (6%) (p = 0.10). We found a significant decrease in total mutational burden (TMB) that has been associated with immunotherapy response comparing non-progressors, progressors and metastatic tumors at 15, 10.1 and 5.1 mutations/MB respectively (p = 0.02). This association suggests more advanced tumors have decreased neoantigen burden and may explain the mechanism of BCG response in non-progressors. We found no novel genetic drivers in progressors and HR-NMIBC had many genetic features similar to metastatic BC. Loss of CDKN2A/B may occur late during invasion of BC and may represent an important step in progression. Further research is necessary to evaluate TMB and loss of CDKN2A/B locus as a biomarker for progression of NMIBC.

Impact of the Ki-67 labeling index and p53 expression status on disease-free survival in pT1 urothelial carcinoma of the bladder

Background

The identification of protein biomarkers to guide treatment decisions regarding adjuvant therapies for high-risk non-muscle-invasive bladder cancer (NMIBC) has been of increasing interest. Evidence of the impact of tumor suppressor gene product p53 and cell proliferation marker Ki-67 on oncologic outcomes in bladder cancer patients at highest risk of recurrence and progression is partially contradictory. We sought to mirror contemporary expression patterns of p53 and Ki-67 in a select cohort of patients with pT1 bladder cancer.

Methods

Patients from four Northern German institutions with a primary diagnosis of pT1 bladder cancer between 2009 and 2016 and complete data regarding p53 or Ki-67 expression status were included for final analyses. Baseline patient characteristics (age, gender, age-adjusted Charlson comorbidity index) and tumor characteristics [diagnostic sequence, tumor focality, concomitant carcinoma in situ, 1973 World Health Organization (WHO) grading, lymphovascular invasion, adjuvant instillation therapy] were abstracted by retrospective chart review. Immunohistochemistry for detection of p53 and Ki-67 expression was performed according to standardized protocols. Microscopic analyses were performed by central pathologic review. First, we compared patients with positive vs. negative p53 expression and Ki-67 labeling index [>40% vs. ≤40%; cutoffs based on best discriminative ability in univariable Cox regression analysis with disease-free survival (DFS) as endpoint] with regard to baseline and tumor characteristics. Second, we evaluated the effect of biomarker positivity on DFS by plotting univariable Kaplan-Meier curves and performing uni- and multivariable Cox regression analyses.

Results

Of 102 patients with complete information on p53 status, 44 (43.1%) were p53 positive, and they more often harbored concomitant carcinoma in situ (50.0% vs. 27.6%; P=0.032) and 1973 WHO grade 3 (97.7% vs. 69.0%; P=0.001) compared to their p53 negative counterparts. Of 79 patients with complete information on Ki-67 expression status, 30 (38.0%) had a labeling index >40%. Mean Ki-67 labeling index was higher in WHO grade 3 vs. grade 2 tumors (45.8 vs. 29.7; P=0.004). At a median follow-up of 51.0 months, 31/91 patients with complete follow-up information (34.1%) suffered from disease recurrence or progression. In univariable Kaplan-Meier analyses, no difference regarding DFS was found in p53 positive vs. negative (P=0.8) or Ki-67 labeling index >40% vs. ≤40% (P=0.078) patients. In multivariable analyses, Ki-67 labeling index >40% remained an independent predictor of DFS [hazard ratio (HR), 2.66; 95% confidence interval (CI), 1.02–6.95; P=0.046], after adjusting for p53 expression and lymphovascular invasion. However, p53 status was not associated with our endpoint (P=0.8).

Conclusions

While we found an association of a Ki-67 labeling index >40% and shorter DFS in pT1 bladder cancer patients, this did not hold true for p53 positivity. Future research is needed to identify additional microscopic and molecular risk factors and biomarker panels to improve risk stratification and guide adjuvant therapies in those patients.

Tp53 and its potential therapeutic role as a target in bladder cancer

INTRODUCTION

Despite more than 30 years of research on p53 resulting in >50,000 publications, we are now beginning to figure out the complexity of the p53 pathway, gene ontology and conformational structure of the molecule. Recent years brought great advances in p53 related drugs and the potencial ways in which p53 is inactivated in cancer. Areas covered: We searched for related publications on Pubmed and ClinicalTrial.gov using the following keywords 'p53, Tp53, p53 and bladder cancer, p53 and therapeutic target'. Relevant articles improved the understanding on p53 pathways and their potential as candidate to targeted therapy in bladder cancer. Expert opinion: Novel strategies developed to restore the function of mutants with chemical chaperones or by using compounds to improved pharmacokinetic properties are in development with potential to be applied in the oncology clinic. Other strategies targeting aberrantly overexpressed p53 regulators with wild-type p53 are also an active area of research. In particular, studies inhibiting the interaction of p53 with its negative regulators MDMX and MDM2 are an important field in drug discovery. Small molecules for inhibition of MDM2 are now in clinical trials process. However, personalized anticancer therapy might eventually advance through analyses of p53 status in cancer patients.

p53 status correlates with the risk of progression in stage T1 bladder cancer: a meta-analysis

Background

Published studies have yielded inconsistent results on the relationship between p53 status and the progression of stage T1 non-muscle invasive bladder cancer (NMIBC). Therefore, we performed a meta-analysis to evaluate the prognostic value of p53 in T1 NMIBC.

Methods

We systematically searched for relevant literatures in MEDLINE, EMBASE, and Web of Science. Data were pooled together from individual studies, and meta-analysis was performed. Study quality was assessed using the Newcastle-Ottawa Scale. Pooled risk ratios (RRs) and 95 % CI were calculated to estimate the effect sizes. Moreover, subgroup analyses were carried out.

Results

A total of 12 studies comprising 712 patients were subjected to the final analysis. p53 overexpression was significantly associated with higher progression rate of T1 NMIBC (RR 2.32, 95 % CI 1.59–3.38). Moderate heterogeneity was observed across the studies (I² = 39 %, P < 0.0001). In a subgroup analysis stratified by stage, p53 overexpression was a predictor of progression in T1 grade 3 NMIBC (RR 2.71, 95 % CI 1.31–5.64). In addition, in a subgroup analysis stratified by intravesical therapy, p53 overexpression was a predictor of progression in T1 NMIBC received Bacillus Calmette-Guérin intravesical therapy (RR 3.35, 95 % CI 1.89–5.93). Furthermore, after excluding the study that possibly contributed to the heterogeneity by the sensitivity analysis, the association p53 overexpression was significantly correlated with progression of T1 NMIBC (RR 2.74, 95 % CI 2.05–3.65) without evidence of heterogeneity (I² = 0 %, P < 0.0001).

Conclusions

This meta-analysis suggested that p53 overexpression may be associated with progression of T1 NMIBC patients. Because of the heterogeneity and other limitations, further studies with rigid criteria and large populations are still warranted to confirm our findings.

Can recurrence and progression be predicted by HYAL-1 expression in primary T1 bladder cancer?

BACKGROUND

Molecular prognostic markers have been under investigation for the last decade and no validated marker to date has been proven to be used in daily clinical practice for urinary bladder cancers. The aim of the present study is to evaluate the significance of HYAL-1 expression in prediction of recurrence and progression in pT1 urothelial carcinomas.

MATERIALS AND METHODS

Eighty-nine urothelial carcinoma cases staged as T1 according to 2004 WHO classification were studied. Representative sections from every case were stained immunohistochemically for HYAL-1 and scored between 0 and +3, according to staining density, and graded as low and high for the scores 0-1 and 2-3, respectively.

RESULTS

Of the 89 pT1 bladder cancer patients, HYAL-1 expression was high in 92.1% (82 patients; 72 patients +3 and 10 patients +2) and low in 7.9% (only 7 patients; 6 patients +1 and 1 patient 0) of the cases. Of the 89 patients, 38 (42.7%) had recurrence and 22 (24.7%) showed progression. HYAL-1 staining did not show significant characteristics for tumor grade, accompanying CIS, multiplicity, tumor size, age and sex. HYAL-1 expression did not have any prognostic value in estimating recurrence or progression.

CONCLUSIONS

HYAL-1 expression was found to be high, but did not have any prognostic importance in T1 bladder urothelial carcinomas.

Management of T1 Urothelial Carcinoma of the Bladder: What Do We Know and What Do We Need To Know?

T1 bladder cancer constitutes approximately 25% of incident bladder cancers, and as such carries an important public health impact. Notably, it has a heterogeneous natural history, with large variation in reported oncologic outcomes. Optimal risk-stratification is essential to individualize patient management, targeting those at greatest risk of progression for aggressive therapies such as early cystectomy, while allowing others to safely pursue bladder-preserving approaches including intravesical bacillus Calmette-Guerrin (BCG). Current strategies for diagnosis, risk-stratification, and treatment are imperfect, but emerging technologies and molecular approaches represent exciting opportunities to advance clinical paradigms in management of this disease entity.

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.

Predicting progression of bladder urothelial carcinoma using microRNA expression

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Recurrence and progression prediction in urothelial cancer is currently based on clinical and pathological factors: tumour grade, tumour stage, number of lesions, tumour size, previous recurrence rate, and presence of concomitant carcinoma in situ. These factors are not specific enough to predict progression and ∼50% of patients diagnosed as high risk in fact do not progress within 3 years. Patient follow-up is both expensive and unpleasant (frequent invasive cystoscopies). Molecular biomarkers, including microRNAs have been studied to provide additional prognostic information for these patients, but to date no molecular biomarker has become the 'gold standard' for patient diagnosis and follow-up. We used Rosetta Genomics' highly specific microRNA expression profiling platforms to study the prognostic role of microRNAs in bladder cancer. Using microdissection we chose specific tumour microRNAs to study in order to avoid background contamination. Tumour progression was associated with altered levels of microRNAs. In particular, high expression levels of miR-29c* were associated with a good prognosis. The study found that the use of microRNAs for determining progression and invasiveness for patients with urothelial cancer could potentially have a substantial impact on the treatment and follow-up individual patients.

OBJECTIVE

To identify microRNAs that could be useful as prognostic markers for non-muscle-invasive (NMI) bladder carcinoma.

PATIENTS AND METHODS

Formalin-fixed, paraffin-embedded samples of 108 NMI bladder carcinomas, and 29 carcinomas invading bladder muscle were collected, and microRNA expression levels were measured using microarrays. For 19 samples, microdissection was performed to compare microRNA expression between the tumour and surrounding tissue. MicroRNAs that were found to be unrelated to the tumour itself were excluded as potential prognostic markers.

RESULTS

Expression profiles identified microRNAs that were differentially expressed in NMI tumours from patients who later progressed to carcinoma invading bladder muscle compared with NMI tumours from patients that did not progress. The microRNA profile of tumours invading the bladder muscle was more similar to that of NMI tumours from patients who later progressed, than to that of the same-stage NMI tumours from patients who did not later progress. The expression level of one microRNA, miR-29c*, was significantly under-expressed in tumours that progressed and could be used to stratify patients with T1 disease into risk groups.

CONCLUSIONS

MicroRNAs can be useful biomarkers for prognosis in patients with urothelial carcinoma. In our study, expression levels of several microRNAs, including miR-29c* identified high- and low-risk groups. These biomarkers show promise for the stratification of patients with bladder cancer.

Prognostic value of molecular markers, sub-stage and European Organisation for the Research and Treatment of Cancer risk scores in primary T1 bladder cancer

What's known on the subject? and What does the study add? The stakes are high when making treatment decisions in T1 bladder cancer (BC). Conservative management may lead to progression and possibly death from BC. Conversely, radical cystectomy could be over-treatment of non-progressive disease. The problem for clinicians is that reliable prognostic indices are lacking. We performed a head-to-head comparison of two substaging systems, European Organisation for the Research and Treatment of Cancer (EORTC) risk scores and four molecular markers in T1 carcinomas of the bladder treated conservatively with BCG. T1 sub-stage according to a new system (micro-invasive [T1m] and extensive-invasive [T1e]) was the most important clinical variable for predicting progression to carcinoma invading bladder muscle. The performance of the EORTC risk scores was disappointing for this T1 sub-group. Molecular markers were not significant in multivariable analysis for predicting progression. Future studies may lead to the incorporation of sub-stage (T1m/T1e) in the TNM classification system for urinary BC to guide clinical decision-making in T1 BC.

OBJECTIVE

To evaluate the prognostic significance of four molecular markers, sub-stage and European Organisation for the Research and Treatment of Cancer (EORTC) risk scores in primary T1 bladder cancer (BC) treated with adjuvant bacille Calmette-Guérin.

PATIENTS AND METHODS

The slides of 129 carcinomas of the bladder from two university hospitals were reviewed and the T1 diagnosis was confirmed. T1 sub-staging was done in two separate rounds, using a new system that identifies micro-invasive (T1m) and extensive-invasive (T1e) T1BC, and then according to invasion of the muscularis mucosae (T1a/T1b/T1c). The EORTC risk scores for recurrence and progression were calculated. Uni- and multivariable analyses for recurrence and progression were performed using clinicopathological variables, T1 sub-stage, EORTC risk scores and molecular markers (fibroblast growth factor receptor 3 gene mutation and Ki-67, P53, P27 expression).

RESULTS

The median follow-up was 6.5 years. Forty-two patients remained recurrence-free (33%). Progression to T2 or metastasis was observed in 38 (30%) patients. In multivariable analysis for recurrence, multiplicity was significant. In multivariable analysis for progression, female gender, sub-stage (T1m/T1e) and carcinoma in situ (CIS) were significant. Molecular markers were significant in univariable and in multivariable analyses for recurrence. EORTC risk scores were not significant.

CONCLUSIONS

CIS, female gender and sub-stage (T1m/T1e) were the most important variables for progression. The additional value of molecular markers was modest. Sub-stage (T1m/T1e) could potentially be incorporated in future tumour-node-metastasis classifications.

The FGFR3 mutation is related to favorable pT1 bladder cancer

PURPOSE

Stage pT1 bladder cancer comprises a heterogeneous group of tumors for which different management options are advocated. FGFR3 mutations are linked to favorable (low grade/stage) pTa bladder cancer while altered P53 is common in cases of high grade, muscle invasive (pT2 or greater) bladder cancer. We determined the frequency of FGFR3 mutations and P53 alterations in patients with pT1 bladder cancer and correlated these data to histopathological variables and clinical outcomes.

MATERIALS AND METHODS

We included 132 patients with primary pT1 bladder cancer from a total of 2 academic centers. A uropathologist reviewed the slides for grade and confirmed the pT1 diagnosis. FGFR3 mutation status was examined by SNaPshot® analysis and P53 expression was determined by standard immunohistochemistry. Kaplan-Meier and multivariate analyses were used to assess progression.

RESULTS

FGFR3 mutations were detected in 37 of 132 pT1 bladder cancer cases (28%) and altered P53 was seen in 71 (54%). Only 8% of patients had the 2 molecular alterations (p = 0.001). FGFR3 mutation correlated with lower grade and altered P53 correlated with high grade pT1 bladder cancer. Median followup was 6.5 years. FGFR3 mutation status and carcinoma in situ were significant for predicting progression on univariate and multivariate analyses but P53 status was not.

CONCLUSIONS

FGFR3 mutations selectively identify patients with pT1 bladder cancer who have favorable disease characteristics. Further study may confirm that FGFR3 identifies those who would benefit from a conservative approach to the disease.

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.

Statistical consideration for clinical biomarker research in bladder cancer

OBJECTIVE

To critically review and illustrate current methodological and statistical considerations for bladder cancer biomarker discovery and evaluation.

METHODS

Original, review, and methodological articles, and editorials were reviewed and summarized.

RESULTS

Biomarkers may be useful at multiple stages of bladder cancer management: early detection, diagnosis, staging, prognosis, and treatment; however, few novel biomarkers are currently used in clinical practice. The reasons for this disjunction are many and reflect the long and difficult pathway from candidate biomarker discovery to clinical assay, and the lack of coherent and comprehensive processes (pipelines) for biomarker development. Conceptually, the development of new biomarkers should be a process that is similar to therapeutic drug evaluation-a highly regulated process with carefully regulated phases from discovery to human applications. In a further effort to address the pervasive problem of inadequacies in the design, analysis, and reporting of biomarker prognostic studies, a set of reporting recommendations are discussed. For example, biomarkers should provide unique information that adds to known clinical and pathologic information. Conventional multivariable analyses are not sufficient to demonstrate improved prediction of outcomes. Predictive models, including or excluding any new putative biomarker, need to show clinically significant improvement of performance in order to claim any real benefit. Towards this end, proper model building, avoidance of overfitting, and external validation are crucial. In addition, it is important to choose appropriate performance measures dependent on outcome and prediction type and to avoid the use of cutpoints. Biomarkers providing a continuous score provide potentially more useful information than cutpoints since risk fits a continuum model. Combination of complementary and independent biomarkers is likely to better capture the biological potential of a tumor than any single biomarker. Finally, methods that incorporate clinical consequences such as decision curve analysis are crucial to the evaluation of biomarkers.

CONCLUSIONS

Attention to sound design and statistical practice should be delivered as early as possible and will help maximize the promise of biomarkers for patient care. Studies should include a measure of predictive accuracy and clinical decision-analysis. External validation using data from an independent cohort provides the strongest evidence that a model is valid. There is a need for adequately assessed clinical biomarkers in bladder cancer.

Clinical outcome in a contemporary series of restaged patients with clinical T1 bladder cancer

OBJECTIVES

To evaluate the indications for early and deferred cystectomy and to report the impact of this tailored approach on survival.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively studied 523 patients seen at our institution who were initially diagnosed with T1 disease between 1990 and 2007.

MEASUREMENTS

Variables analyzed included age, gender, multifocality, multifocal T1 disease, carcinoma in situ, grade, recurrence rate, and restaging status. End points were overall and disease-specific survival.

RESULTS AND LIMITATIONS

A restaging transurethral resection (TUR) was performed in 523 patients. Of the patients who underwent restaging, 106 (20%) were upstaged to muscle-invasive disease and 417 patients were considered true clinical T1 (cT1); 84 of the latter group underwent immediate cystectomy. The median follow-up for survivors was 4.3 yr. The cumulative incidence of disease-specific death at 5 yr was 8% (95% confidence interval [CI], 5-13%), 10% (95% CI, 5-17%), and 44% (95% CI, 35-56%) for those restaged with lower than T1, T1, and T2 disease, respectively. Immediate cystectomy was more likely in patients with cT1 disease at restaging than in those with disease lower than cT1, but there were no other obvious differences in clinical characteristics between those with and without immediate cystectomy. Survival was not statistically different for patients who underwent an immediate cystectomy versus those who were maintained on surveillance with deferred cystectomy if deemed appropriate. Of 333 patients who did not undergo immediate cystectomy, 59 had a deferred cystectomy, and the likelihood of deferred cystectomy was greater in those with T1 disease on restaging TUR (hazard ratio: 2.40; 95% CI, 1.43-4.01; p=0.001).

CONCLUSIONS

Restaging TUR should be performed in patients diagnosed with cT1 bladder cancer to improve staging accuracy. Patients with T1 disease on restaging are at higher risk of progression and should be considered for early cystectomy.

Molecular biomarkers for urothelial carcinoma of the bladder: challenges in clinical use

Conventional clinical and pathological parameters are limited in their capacity to detect patients with urothelial carcinoma of the bladder (UCB) who are at high risk for recurrence or mortality. The assessment of molecular biomarkers in surgical UCB specimens offers additional information on the biology of the disease, and might improve the prediction of oncologic end points. A wide range of candidate biomarkers, including key cell-cycle regulators, apoptotic markers and specific growth factors, have been reported to be of prognostic value. To date, however, no molecular biomarker for UCB has been introduced into clinical practice, mainly owing to insufficient validation and the absence of prospective studies. Knowledge about the value of molecular biomarkers in predicting the response to adjuvant or neoadjuvant therapies is also lacking. Prospective trials need to be initiated in high-risk patients selected on the basis of the expression patterns of molecular biomarkers that have already passed the initial steps towards clinical utility.

Utility of diagnostic and prognostic markers in urothelial carcinoma of the bladder

Urothelial carcinoma (UCC) of the bladder demonstrates diverse morphologic features, often leading to diagnostic challenges in the discrimination between UCC and benign mimickers of neoplasia, and between primary UCC and secondary neoplasms involving the bladder. In situ lesions also provide diagnostic difficulty in some instances, most prominently in the distinction between normal, reactive urothelium and flat urothelial carcinoma in situ. The use of ancillary techniques, including panels of immunohistochemical markers, in distinguishing these entities has aided not only in the diagnosis of UCC, but has also provided insight into the molecular pathogenesis and prognostic value of numerous molecular pathways in UCC. This review focuses on some of the more commonly encountered biomarkers in UCC and their role in addressing key diagnostic and prognostic issues in this disease process.

Bladder tumor markers: from hematuria to molecular diagnostics--where do we stand?

Bladder cancer is a common malignancy in the USA. Currently, the detection of initial tumors and recurrent disease is based on evaluation of voided urinary specimens, often followed by cystoscopy. With the high rate of recurrence, cystoscopies are regularly repeated with the aim of halting progression of the disease. For patients, this process is fraught with anxiety, pain and high cost. As a result, intense work is being done in the field of bladder tumor markers with the goal of identifying bladder cancer earlier, both in the initial diagnosis and in recurrences of known tumor. The possibility of identifying a marker that could noninvasively differentiate benign and malignant causes of hematuria, and identify recurrences prior to their pathologic progression is the objective of this area of research. Currently, a large number of tumor markers exist, each scrutinized in both the laboratory and in clinical trials. Here we present many of the most widely used and tested markers. Background details are provided as to the mechanism of detection of malignant cells, the results of recent trials and future directions of study. Some novel modalities for tumor detection are also presented. The next few years will no doubt bring newer markers and lead to the elimination of others. Studies continue to refine the role of these markers in clinical practice, but their ultimate efficacy will need to be borne out in large-scale clinical trials in a multitude of settings.

Differential cancer predisposition in Lynch syndrome: insights from molecular analysis of brain and urinary tract tumors

Hereditary non-polyposis colorectal carcinoma (Lynch syndrome) is among the most common hereditary cancers in man and a model of cancers arising through deficient DNA mismatch repair (MMR). Lynch syndrome patients are predisposed to different cancers in a non-random fashion, the basis of which is poorly understood. We addressed this issue by determining the molecular profiles for different tumors from a nationwide cohort of Lynch syndrome families (approximately 150 tumors in total). We focused on some less prevalent cancers, affecting the brain (n = 7) and urinary tract (five bladder and five ureter uroepithelial cancers and four kidney adenocarcinomas), and compared their molecular characteristics to those of the most common cancers, colorectal, gastric and endometrial adenocarcinomas, from the same families. Despite origin from verified MMR gene mutation carriers, the frequency of high-level microsatellite instability in tumors varied between high (100-96% for ureter, stomach and colon), intermediate (63-60% for endometrium and bladder) and low (25-0% for kidney and brain). In contrast to gastrointestinal and endometrial carcinomas, active (nuclear) beta-catenin was rare and KRAS mutations were absent in brain and urological tumors. Compared with other tumors, frequent stabilization of p53 protein characterized urinary tract cancers. Promoter methylation of tumor suppressor genes discriminated the tumors in an organ-specific manner. Our findings suggest that different Lynch syndrome tumors develop along different routes. Uroepithelial cancers of the ureter (and bladder to lesser extent) share many characteristics of MMR deficiency-driven tumorigenesis, whereas brain tumors and kidney adenocarcinomas follow separate pathways.

Molecular markers in bladder cancer

PURPOSE OF REVIEW

Bladder cancer is a diverse disease whose molecular phenotypes are being elucidated. In this review, we summarize currently known molecular pathways and associated markers in bladder cancer.

RECENT FINDINGS

Genetic and epigenetic aberrations have been closely associated with tumor pathogenesis and prognosis. Cell cycle markers have been most extensively studied. More recently, apoptotic and angiogenic pathways are being investigated. Studying the role of multiple concurrent molecular alterations improves the prognostic ability of these markers. The use of tissue microarrays and high-throughput molecular profiling is accelerating the discovery of new markers.

SUMMARY

Molecular biology is paramount to our understanding of bladder cancer pathogenesis. The search for new markers, and elucidating cross-talk between markers in different pathways, is warranted. Molecular markers have the potential benefit of improving detection, prognosis and treatment of bladder cancer. In addition, understanding the molecular profile of the individual patient could usher us into a new era of improving prediction of the natural history of the disease and providing a more personalized and tailored treatment. Prospective trials are still needed, however, to objectively establish the true benefit of these markers in prognostic and therapeutic arenas.