Oligoclonality in bladder cancer: the implication for molecular therapies

Genomic characteristics and evolution of Multicentric Esophageal and gastric Cardiac Cancer

BACKGROUND

Esophageal carcinoma (EC) and gastric cardiac adenocarcinoma (GCA) have high incidence rates in the Chaoshan region of South China. Multifocal esophageal and cardiac cancer (MECC) is commonly observed in this region in clinical practice. However, the genomic characteristics of MECC remains unclear.

MATERIALS AND METHODS

In this study, a total of 2123 clinical samples of EC and GCA were analyzed to determine the frequency of multifocal tumors, as well as their occurrence sites and pathological types. Cox proportional hazards regression was used to model the relationship between age, sex, and tumor state concerning survival in our analysis of the cohort of 541 patients with available follow-up data. We performed whole-genome sequencing on 20 tumor foci and 10 normal samples from 10 MECC patients to infer clonal structure on 6 MECC patients to explore genome characteristics.

RESULT

The MECC rate of EC and GCA was 5.65% (121 of 2123). Age and sex were potential factors that may influence the risk of MECC (p < 0.001). Furthermore, MECC patients showed worse survival compared with single tumor patients. We found that 12 foci from 6 patients were multicentric origin model (MC), which exhibited significant heterogeneity of variations in paired foci and had an increased number of germline mutations in immune genes compared to metastatic model. In MC cases, different lesions in the same patient were driven by distinct mutation and copy number variation (CNV) events. Although TP53 and other driver mutation genes have a high frequency in the samples, their mutation sites show significant heterogeneity in paired tumor specimens. On the other hand, CNV genes exhibited higher concordance in paired samples, especially in the amplification of oncogenes and the deletion of tumor suppressor genes.

CONCLUSIONS

The extent of inter-tumor heterogeneity suggests both monoclonal and polyclonal origins of MECC, which could provide insight into the genome diversity of MECC and guide clinical implementation.

E-cadherin expressions on bladder and its association with cancer progressivity: a retrospective cohort study

Background

Bladder cancer is characterized by high recurrence and progressivity. E-cadherin serves as one of the most important molecules involved in the epithelial cells’ cell-to-cell adherence, suggested to inhibit tumor cell progression. This study aims to investigate the association between the E-cadherin expressions with bladder cancer progressiveness in 3 years.

Methods

This study was a retrospective cohort study involving bladder cancer patients in Cipto Mangunkusumo Hospital, Jakarta. Diagnosis of bladder cancers was confirmed by histopathological and immunohistochemistry examination between 2011 and 2018, with both grading and staging determined by uropathologists and uro-oncologists. E-cadherin was examined through immunohistochemistry examination at the time of diagnosis. Data on demography, muscle invasion, clinical staging, grade, metastasis, multifocality, and recurrence were obtained from medical records and pathology reports. The association of E-cadherin expression to muscle invasion and non-muscle invasion bladder cancer was evaluated and statistically analyzed. Patients’ survival data were followed up by phone.

Results

Forty bladder cancer patients with a mean age of 60.05 ± 10.3 years were included. Most subjects had high E-cadherin expression (85%), muscle invasion (65%), high grade (65%), no metastasis (87.5%), multifocality (65%), and no recurrence (62.5%). Lower expression of E-cadherin was associated with the higher clinical stage (p < 0.02) and metastasis (p < 0.001). Patients with low E-cadherin expression showed worse cumulative survival than the high one (mean 32 months vs. 25 months, p = 0.13).

Conclusions

Low level of E-cadherin was associated with the higher risk of muscle invasion, clinical staging, histological grade, and risk of metastasis. Meanwhile, patients with the high level of E-cadherin showed a better three-year survival rate.

Epidemiology, clinical presentation, and evaluation of upper-tract urothelial carcinoma

An overview of epidemiological pattern of upper tract urothelial carcinoma (UTUC), including outcome of UTUC over past decades as well as factors responsible for observed epidemiological changes was performed. Gender and racial disparities influencing incidence of UTUC were reviewed. The incidence of multifocal urothelial carcinoma and relation of UTUC to urothelial carcinoma of bladder were examined.

Epidermal Growth Factor Receptor and Ki-67 as Predictive Biomarkers Identify Patients Who Will Be More Sensitive to Intravesical Instillations for the Prevention of Bladder Cancer Recurrence after Radical Nephroureterectomy

BACKGROUND

To date, prophylactic intravesical chemotherapy after radical nephroureterectomy is one of the few available treatments that effectively prevent secondary bladder cancer. However, treating all patients with prophylactic intravesical chemotherapy is excessive for patients who are at a low risk or insensitive to the treatment. Thus, to guide individualized clinical treatment, in addition to identifying patients who are at risk of bladder cancer recurrence, it is equally necessary to identify the patients who will benefit the most from prophylactic, postoperative intravesical instillation therapy.

METHODS

Epidermal growth factor receptor (EGFR) and Ki-67 expression levels were measured using immunohistochemical staining samples from 320 patients with upper urinary tract urothelial carcinoma (UTUC) from 2004 to 2012. Although no patients received intravesical chemotherapy after RNU before 2008, this method began to be used in 2008 to prevent bladder cancer recurrence. To identify the patients who would most benefit from intravesical chemotherapy, we assessed biological interactions between intravesical chemotherapy and clinicopathological factors or biomarkers.

RESULTS

The incidence rates of bladder UTUC recurrence decreased after intravesical chemotherapy, and the decrease was greater in patients with low Ki-67 levels, negative EGFR staining and preoperative positive urine cytology. Biological interactions were observed between intravesical chemotherapy, low-level Ki-67 and EGFR negativity. The multivariate analysis showed that after balancing a variety of factors, intravesical chemotherapy is a protective factor for preventing intravesical recurrence in the negative EGFR, low-level Ki-67 and preoperative positive urine cytology sub-groups but not in their corresponding sub-groups. Additionally, the multivariate analysis revealed that preoperative positive urine cytology and Ki-67 were not but that EGFR positivity was an independent risk factor for recurrence after intravesical chemotherapy.

CONCLUSIONS

Patients with low Ki-67 levels, negative EGFR staining and preoperative positive urine cytology appear to be more sensitive to intravesical instillations for bladder recurrence prevention after RNU.

Production of urothelium from pluripotent stem cells for regenerative applications

As bladder reconstruction strategies evolve, a feasible and safe source of transplantable urothelium becomes a major consideration for patients with advanced bladder disease, particularly cancer. Pluripotent stem cells, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), are attractive candidates from which to derive urothelium as they renew and proliferate indefinitely in vitro and fulfill the non-autologous and/or non-urologic criteria, respectively, that is required for many patients. This review presents the latest advancements in differentiating urothelium from pluripotent stem cells in vitro in the context of current bladder tissue engineering strategies.

Quantitation of rare circulating tumor cells by folate receptor α ligand-targeted PCR in bladder transitional cell carcinoma and its potential diagnostic significance

Numerous attempts for detection of circulating tumor cells (CTC) have been made to develop reliable assays for early diagnosis of cancers. In this study, we validated the application of folate receptor α (FRα) as the tumor marker to detect CTC through tumor-specific ligand PCR (LT-PCR) and assessed its utility for diagnosis of bladder transitional cell carcinoma (TCC). Immunohistochemistry for FRα was performed on ten bladder TCC tissues. Enzyme-linked immunosorbent assay (ELISA) for FRα was performed on both urine and serum specimens from bladder TCC patients (n = 64 and n = 20, respectively) and healthy volunteers (n = 20 and n = 23, respectively). Western blot analysis and qRT-PCR were performed to confirm the expression of FRα in bladder TCC cells. CTC values in 3-mL peripheral blood were measured in 57 bladder TCC patients, 48 healthy volunteers, and 15 subjects with benign urologic pathologies by the folate receptor α ligand-targeted PCR. We found that FRα protein was overexpressed in both bladder TCC cells and tissues. The levels of FRα mRNA were also much higher in bladder cancer cell lines 5637 and SW780 than those of leukocyte. Values of FRα were higher in both serum and urine specimens of bladder TCC patients than those of control. CTC values were also higher in 3-mL peripheral blood of bladder TCC patients than those of control (median 26.5 Cu/3 mL vs 14.0 Cu/3 mL). Area under the receiver operating characteristic (ROC) curve for bladder TCC detection was 0.819, 95 % CI (0.738-0.883). At the cutoff value of 15.43 Cu/3 mL, the sensitivity and the specificity for detecting bladder cancer are 82.14 and 61.9 %, respectively. We concluded that quantitation of CTCs through FRα ligand-PCR could be a promising method for noninvasive diagnosis of bladder TCC.

Cellular origin of bladder neoplasia and tissue dynamics of its progression to invasive carcinoma

Understanding how malignancies arise within normal tissues requires identification of the cancer cell of origin and knowledge of the cellular and tissue dynamics of tumor progression. Here we examine bladder cancer in a chemical carcinogenesis model that mimics muscle-invasive human bladder cancer. With no prior bias regarding genetic pathways or cell types, we prospectively mark or ablate cells to show that muscle-invasive bladder carcinomas arise exclusively from Sonic hedgehog (Shh)-expressing stem cells in basal urothelium. These carcinomas arise clonally from a single cell whose progeny aggressively colonize a major portion of the urothelium to generate a lesion with histological features identical to human carcinoma-in-situ. Shh-expressing basal cells within this precursor lesion become tumor-initiating cells, although Shh expression is lost in subsequent carcinomas. We thus find that invasive carcinoma is initiated from basal urothelial stem cells but that tumor cell phenotype can diverge significantly from that of the cancer cell-of-origin.

Comparison of the clonality of urothelial carcinoma developing in the upper urinary tract and those developing in the bladder

Purpose

To identify the origin of synchronous and metachronous urothelial carcinoma (UC) of the bladder and upper urinary tract to get a better understanding of the basic mechanism behind the multifocality of UC, which may provide a sound bases for the future development of new strategies for detection, prevention and therapy.

Methods

Six patients with UC of the bladder and synchronous or metachronous UC of the upper urinary tract were studied. Genetic analysis involving the study of loss of heterozygosity (LOH) has been evaluated on their tumours using well characterised and new markers of UC (D9S171, D9S177, D9S303 and TP53).

Results

Five of the six patients demonstrated informative results. Four of five (80%) of patients had synchronous or metacharonous UC tumour and showed patterns of LOH consistent with tumorigenesis from monoclonal tumour origin. One of five (20%) patients exhibited a LOH consistent with oligoclonal tumorigenesis.

Conclusion

These findings suggest that both the monoclonal and field cancerization theory of tumorigenesis may play a role in tumors of the urothelial tract. However, more data is needed.

Laser-assisted microdissection in translational research: theory, technical considerations, and future applications

Molecular profiling already exerts a profound influence on biomedical research and disease management. Microdissection technologies contribute to the molecular profiling of diseases, enabling investigators to probe genetic characteristics and dissect functional physiology within specific cell populations. Laser-capture microdissection (LCM), in particular, permits collation of genetic, epigenetic, and gene expression differences between normal, premalignant, and malignant cell populations. Its selectivity for specific cell populations promises to greatly improve the diagnosis and management of many human diseases. LCM has been extensively used in cancer research, contributing to the understanding of tumor biology by mutation detection, clonality analysis, epigenetic alteration assessment, gene expression profiling, proteomics, and metabolomics. In this review, we focus on LCM applications for DNA, RNA, and protein analysis in specific cell types and on commercially available LCM platforms. These analyses could clinically be used as aids to cancer diagnosis, clinical management, genomic profile studies, and targeted therapy. In this review, we also discuss the technical details of tissue preparation, analytical yields, tissue selection, and selected applications using LCM.

Tumour multiplicity as a risk factor for the development of bladder tumours after primary upper urinary tract cancer

Objective:

To determine the independent risk factors for intravesical tumour recurrence in patients with primary urothelial cancer of the upper urinary tract.

Patients and methods:

Of the 60 patients who underwent nephroureterectomy for urothelial cancer of the upper urinary tract, the data from 49 patients were retrospectively reviewed. Patients with a previous history or concomitance of bladder cancer were excluded from the study. Multivariate analysis by Cox’s proportional hazards model was used to determine independent risk factors for intravesical tumour recurrence.

Results:

Of the 49 patients reviewed, 22 (44.9%) experienced subsequent intravesical tumour recurrence during a mean follow-up period of 26 months (range 3–103). On multivariate analysis, tumour multiplicity had a statistically significant impact on the risk of intravesical tumour recurrence ( P < 0.01).

Conclusion:

Neither the pathology of the upper urinary tract cancers nor the method of treatment was associated with recurrent bladder cancers. Only tumour multiplicity had a significant impact on the incidence of intravesical tumour recurrence.

Use of preclinical models to assess the therapeutic potential of new drug candidates for bladder cancer

The purpose of this review is to demonstrate a successful use of preclinical models of bladder cancer to confirm the therapeutic potential of new promising drug candidates. The bladder has long been thought to be an ideal target for investigating therapies. When developing a new antineoplastic pharmaceutical agent, the bladder should be considered for use as an experimental model demonstrating initial proof of concept that if successful can be later assessed in further cancer indications. Non-muscle-invasive bladder carcinoma can be removed by transurethral resection but these cancers tend to recur in most patients. Conventional treatments decrease the recurrence rate but are associated with side effects and frequent failures. Thus, there is an obvious need for the development of highly effective targeted therapies with limited side effects. Accordingly, a double-promoter vector was developed, expressing diphtheria toxin A (DTA) under control of two different regulatory promoter sequences, H19 and IGF2. This vector was then used to transfect and to eradicate tumor cells in bladder cancer models, effectively destroying tumor cells without affecting normal cells. Our studies demonstrate the potential efficacy of the therapeutic vector and should be a solid base for future clinical studies. These models illuminate the path for future investigations of new drug candidates for bladder cancer.

Preoperative prognostic factors after radical nephroureterectomy in patients with upper urinary tract urothelial carcinoma

PURPOSE

To evaluate the clinical significance of preoperative biomarkers such as laboratory data, Eastern Cooperative Oncology Group Performance Status (ECOG PS) and clinicopathological factors in patients undergoing radical nephroureterectomy for upper urinary tract urothelial carcinoma.

METHODS

Between 1995 and 2011, a total of 99 patients treated at our institution for upper urinary tract urothelial carcinoma were enrolled in this study. The prognostic significance of various preoperative data and clinicopathological factors were analyzed. Univariate and multivariate analyses were performed using the Kaplan-Meier method with the log-rank test and a Cox proportional hazards regression model.

RESULTS

Median patient age was 73 years (range 44-86 years), and the median follow-up period after radical nephroureterectomy was 37.9 months (range 6.6-171.4 months). The 5-year intravesical recurrence-free survival and cancer-specific survival estimates were 47.1 and 70.0 %, respectively. On multivariate analysis, concomitant bladder carcinoma was an independent predictor of intravesical recurrence (hazard ratio 3.689; P = 0.002), and infiltration (hazard ratio 14.842; P = 0.002), preoperative serum creatinine level (hazard ratio 9.992; P = 0.005), preoperative serum hemoglobin level (hazard ratio 6.370; P = 0.018) and ECOG PS (hazard ratio 4.326; P = 0.037) were associated with worse cancer-specific survival. This study is limited by biases associated with its retrospective design.

CONCLUSIONS

This study indicates that not only clinicopathological factors, but also preoperative biomarkers, such as serum creatinine and hemoglobin levels and ECOG PS, predict a poor survival in patients with upper urinary tract urothelial carcinoma.

Inhibition of bladder cancer by broccoli isothiocyanates sulforaphane and erucin: characterization, metabolism, and interconversion

SCOPE

Epidemiologic evidence suggests diets rich in cruciferous vegetables, particularly broccoli, are associated with lower bladder cancer risk. Our objectives are to investigate these observations and determine the role of isothiocyanates in primary or secondary bladder cancer prevention.

METHODS AND RESULTS

We initially investigate the mechanisms whereby broccoli and broccoli sprout extracts and pure isothiocyanates inhibit normal, noninvasive (RT4), and invasive (J82, UMUC3) human urothelial cell viability. Sulforaphane (IC(50) = 5.66 ± 1.2 μM) and erucin (IC(50) = 8.79 ± 1.3 μM) are found to be the most potent inhibitors and normal cells are least sensitive. This observation is associated with downregulation of survivin, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/neu), G(2) /M cell cycle accumulation, and apoptosis. In a murine UMUC3 xenograft model, we fed semipurified diets containing 4% broccoli sprouts, or 2% broccoli sprout isothiocyanate extract; or gavaged pure sulforaphane or erucin (each at 295 μmol/kg, similar to dietary exposure); and report tumor weight reduction of 42% (p = 0.02), 42% (p = 0.04), 33% (p = 0.04), and 58% (p < 0.0001), respectively. Sulforaphane and erucin metabolites are present in mouse plasma (micromolar range) and tumor tissue, with N-acetylcysteine conjugates as the most abundant. Interconversion of sulforaphane and erucin metabolites was observed.

CONCLUSION

This work supports development of fully characterized, novel food products containing broccoli components for phase I/II human studies targeting bladder cancer prevention.

Tissue engineering for the oncologic urinary bladder

Urinary diversion after radical cystectomy in patients with bladder cancer normally takes the form of an ileal conduit or neobladder. However, such diversions are associated with a number of complications including increased risk of infection. A plausible alternative is the construction of a neobladder (or bladder tissue) in vitro using autologous cells harvested from the patient. Biomaterials can be used as a scaffold for naturally occurring regenerative stem cells to latch onto to regrow the bladder smooth muscle and epithelium. Such engineered tissues show great promise in urologic tissue regeneration, but are faced with a number of challenges. For example, the differentiation mesenchymal stem cells from various sources can be difficult and the smooth muscle cells formed do not precisely mimic the natural cells.

Pathobiology and chemoprevention of bladder cancer

Our understanding of the pathogenesis of bladder cancer has improved considerably over the past decade. Translating these novel pathobiological discoveries into therapies, prevention, or strategies to manage patients who are suspected to have or who have been diagnosed with bladder cancer is the ultimate goal. In particular, the chemoprevention of bladder cancer development is important, since urothelial cancer frequently recurs, even if the primary cancer is completely removed. The numerous alterations of both oncogenes and tumor suppressor genes that have been implicated in bladder carcinogenesis represent novel targets for therapy and prevention. In addition, knowledge about these genetic alterations will help provide a better understanding of the biological significance of preneoplastic lesions of bladder cancer. Animal models for investigating bladder cancer development and prevention can also be developed based on these alterations. This paper summarizes the results of recent preclinical and clinical chemoprevention studies and discusses screening for bladder cancer.

Oncomutations as biomarkers of cancer risk

Cancer risk assessment impacts a range of societal needs, from the regulation of chemicals to achieving the best possible human health outcomes. Because oncogene and tumor suppressor gene mutations are necessary for the development of cancer, such mutations are ideal biomarkers to use in cancer risk assessment. Consequently, DNA-based methods to quantify particular tumor-associated hotspot point mutations (i.e., oncomutations) have been developed, including allele-specific competitive blocker-PCR (ACB-PCR). Several studies using ACB-PCR and model mutagens have demonstrated that significant induction of tumor-associated oncomutations are measureable at earlier time points than are used to score tumors in a bioassay. In the particular case of benzo[a]pyrene induction of K-Ras codon 12 TGT mutation in the A/J mouse lung, measurement of tumor-associated oncomutation was shown to be an earlier and more sensitive endpoint than tumor response. The measurement of oncomutation by ACB-PCR led to two unexpected findings. First, oncomutations are present in various tissues of control rodents and "normal" human colonic mucosa samples at relatively high frequencies. Approximately 60% of such samples (88/146) have mutant fractions (MFs) >10(-5), and some have MFs as high as 10(-3) or 10(-4). Second, preliminary data indicate that oncomutations are present frequently as subpopulations in tumors. These findings are integrated into a hypothesis that the predominant preexisting mutations in particular tissues may be useful as generic reporters of carcinogenesis. Future research opportunities using oncomutation as an endpoint are described, including rodent to human extrapolation, dose-response assessment, and personalized medicine.

The (CCTTT)n microsatellite polymorphism in the nitric oxide synthase 2 gene may influence bladder cancer pathogenesis

PURPOSE

We analyzed whether the NOS2 promoter microsatellite (CCTTT)n polymorphism influences bladder cancer pathogenesis.

MATERIALS AND METHODS

We genotyped 359 patients with bladder cancer in a population based cohort and 164 population controls by DNA fragment analysis and sequencing. Genotypes were combined with information on tumor stage, grade and stage, grade progression and cancer specific death. Clinical followup was 5 years.

RESULTS

We divided (CCTTT)n alleles into short-10 or fewer, intermediate-11 or 12 and long-13 or greater repeats. Patients homozygous for 13 or longer (CCTTT)n repeats were at decreased odds ratio for bladder cancer (p = 0.010). However, after illness developed they were at 3-fold increased hazard ratio for stage progression (p = 0.062) and 4-fold increased hazard ratio for death from bladder cancer (p = 0.056). We discovered what is to our knowledge a previously undescribed polymorphism at position 23105343 (C/T). There was no difference in frequency between bladder cancer cases and population controls for this polymorphism. No associations were found between tumor stage, grade or stage and grade progression. However, patients with bladder cancer with the heterozygous CT genotype were at 3-fold increased hazard ratio of death from cancer (p = 0.011).

CONCLUSIONS

Nitric oxide can induce proliferation or apoptosis depending on the cellular context. Results suggest that the (CCTTT)n NOS2 microsatellite may influence bladder cancer risk and aggressiveness. This polymorphism may have an impact on disease pathogenesis, possibly by affecting intracellular nitric oxide levels.

K-RAS mutation in the screening, prognosis and treatment of cancer

The potential use of K-RAS mutation as a cancer screening biomarker has been investigated for many years. Numerous associations between K-RAS mutation and various cancers have been established, but these associations have not been translated into effective, cost-efficient cancer screening strategies. This lack of progress may be due to the existence of K-RAS mutation in nontumor tissues and/or using detection, rather than quantitation, of K-RAS mutation as the endpoint for cancer risk categorization. K-RAS mutation appears to be a useful prognostic biomarker for colon cancer. Recent progress toward sensitive and quantitative mutation characterization and the successful use of K-RAS mutation in a personalized medicine approach to targeted biological therapy selection are likely to re-direct and expand the use of K-RAS mutation as a cancer biomarker in the near future.

Mechanisms of recurrence of Ta/T1 bladder cancer

INTRODUCTION

Bladder cancer recurrence occurs via four mechanisms - incomplete resection, tumour cell re-implantation, growth of microscopic tumours, and new tumour formation. The first two mechanisms are influenced by clinicians before and immediately after resection; the remaining mechanisms have the potential to be influenced by chemopreventive agents. However, the relative importance and timing of these mechanisms is currently unknown. Our objective was to postulate the incidence and timing of these mechanisms by investigating the location of bladder cancer recurrences over time.

PATIENTS AND METHODS

The topographical locations of tumours and their recurrences were analysed retrospectively for 169 patients newly-diagnosed with Ta/T1 bladder cancer, with median follow-up of 33.8 months. Tumours were assigned to one or more of six bladder sectors, and time to recurrence and location of recurrences were recorded.

RESULTS

Median time to first tumour recurrence was 40 months. Median times between subsequent recurrences were 6.6, 7.9, 8.0 and 6.6 months for recurrences 1 to 2, 2 to 3, 3 to 4, and 4 to 5, respectively. The risk of first tumour recurrence in any given bladder sector increased by nearly 4-fold if the primary tumour was resected from that sector (P < 0.001); this association was not significant for subsequent recurrences. The proportion of tumour recurrences in multiple bladder sectors increased from 13% for the first recurrence to 100% for recurrence seven onwards.

CONCLUSIONS

First tumour recurrence appears different to subsequent recurrences; incomplete resection and tumour cell reimplantation may dominate at this time-point. Only later does genuine new tumour formation appear to increase in importance. This has important implications for clinical trials, especially those involving chemopreventive agents.

Molecular determinants of tumor recurrence in the urinary bladder

Tumor recurrence is a major clinical concern for patients with urothelial carcinoma of the urinary bladder. Traditional morphological analysis is of limited utility for identifying cases in which recurrence will occur. However, molecular and genetic analyses offer new perspectives on the prediction of bladder tumor recurrence. Recent studies have suggested that urothelial carcinogenesis occurs as a 'field effect' that can involve any number of sites in the bladder mucosa. Accumulating evidence supports the notion that resident urothelial stem cells in the affected field are transformed into cancer stem cells by acquiring genetic alterations that lead to tumor formation through clonal expansion. Both initial and recurrent tumors are derived from cancer stem cells in the affected field via two distinct molecular pathways. These provide a genetic framework for understanding urothelial carcinogenesis, tumor recurrence and progression: the FGFR3-associated pathway and the TP53-associated pathway. These two pathways are characterized by different genomic, epigenetic and gene-expression alterations. Their outcomes correlate with the markedly different clinical and pathologic features of both relatively indolent low-grade cancers and the aggressive high-grade cancers. As such, these molecular findings are potentially useful for counseling patients and for assessing risk of recurrence or biological aggressiveness of the patient's tumor. The molecular changes may additionally prove useful for developing preventive and therapeutic strategies for urothelial bladder cancer. A unifying model of urothelial carcinogenesis, tumor recurrence and progression is proposed in this review.

[Predictive factors of metachronous bladder neoplasm after nephroureterectomy]

PURPOSE

To determine prognostic factors of bladder recurrence in patients with upper urinary tract (UUT) urothelial carcinoma, who underwent nephroureterectomy.

MATERIAL AND METHODS

Patients (N = 51) with UUT transitional cell carcinoma who underwent nephroureterectomy. A retrospective and prospective observational cohort study was made during the period 1995-2007, at Arquitecto Marcide Hospital, Ferrol Health Area, La Coruña. Differences between groups with and without recurrence were analized by means of chi-squared test in qualitative variables and t-Student and U Mann-Whitney test in quantitative variables. Kaplan-Meier methodology was used in order to predict bladder recurrence free survival (BRFS), developing a multivariate Cox regression model to identify variables related to bladder recurrence.

RESULTS

Mean age of patients was 68.51 +/- 12.11 (24-86). Histological grade distribution was as follows: 7 G1 (13.72%), 20 G2 (39.21%), 23 G3 (45.10%) and 1 undetermined case (1.97%). With regard to pT category, 19 cases were pT1 (37.25%), 12 pT2 (23.53%), 19 pT3 (37.25%) y 1 case undetermined (1.97%). Bladder recurrence was detected in 16 patients during follow-up (31.37%). 70.59% of recurrences were identified during first two years of follow-up. Differences related to follow-up period, presence of obstructive uropathy, microscopic growth pattern and tumour multifocality, were observed between patients without and with bladder recurrence. BRFS rates at 1, 2, 5 and 10 years were 85.10%, 67.90%, 56.60% y 31.80%, respectively. BRFS was significantly modified by tumour location (p = 0.019) and tumour multifocality (p = 0.002). Multivariate analysis showed that tumour multifocality was an independent factor in the prediction of bladder recurrence (RR = 7.35; 95% CI = 1.57-34.45; p = 0.011).

CONCLUSIONS

The development of bladder recurrence after nephroureterectomy was observed in 31.37% of patients in our study, detecting most of events during the first two years of follow-up. Tumour multifocality in UUT constitutes the most important risk factor for the development of bladder recurrence.

Genomic imbalances in urothelial cancer: intratumor heterogeneity versus multifocality

Comparative genomic hybridization and fluorescence in situ hybridization were used to define genetic changes associated with multifocal bladder cancer and to investigate whether the genetic relationship between synchronous urothelial tumors is similar to that observed within different parts of the same tumor. We investigated 8 synchronous urothelial tumors from 3 patients and macroscopically different parts of the same tumor from 2 other patients. The most frequent imbalances were gains of 1q, 2p, and 17q, and losses in 4q. The high number of chromosome imbalances detected in the present report confirms that a high level of chromosome instability could be characteristic of multicentric bladder tumors. Comparative genomic hybridization profiles obtained from independent tumors belonging to the same patient allowed us to elaborate cytogenetic pedigrees portraying the accumulation of chromosome alterations as a form of clonal evolution from a single precursor cell. The analysis of different macroscopic parts of the same tumor allowed us to detect chromosomal heterogeneity and to delineate intratumor clonal evolution. Some chromosome regions that appeared as a gain in one subpopulation were amplified in others indicating a genetic evolution process. Identical processes were observed in different tumors of the same patient. Expansion of chromosome gains and losses between different parts of the same tumor as well as in different tumors of the same patient was also observed. Our results not only provide further evidence of a clonal relationship between different synchronous bladder tumors but also show that the intratumor heterogeneity present in different subpopulations of the same tumor reproduces the behavior of independent synchronous tumors in a same patient.

Cell Discohesion and Multifocality of Carcinoma In situ of the Bladder: New Insight From the Adhesion Molecule Profile (e-Cadherin, Ep-CAM, and MUC1)

Urothelial cell carcinoma in situ (CIS) of the bladder is a superficially diffusive and highly discohesive disease. The authors analyzed the expression of some adhesion molecules (e-cadherin and Ep-CAM) and MUC1 in 32 unifocal and multifocal bladder urothelial cell CIS in an attempt to clarify this discohesion. E-cadherin was strongly expressed, in more than 75% of the cases. The presence of methylation of the CDH1 e-cadherin promoter gene was also investigated, but methylation was found in only one case. Ep-CAM was present in all the cases with a heterogeneous staining pattern. Similarly, MUC1/episialin was variously present in 94% of the cases without a polarized staining pattern and was expressed more strongly in cases with multifocal disease. Because loss of MUC1 polarization leads to interference with cell—cell adhesion mechanisms mediated by cadherins, these findings help explain why bladder urothelial cell CIS often shows a discohesive morphology and multifocality despite a strongly expressed adhesion molecule profile. Finally, Ep-CAM expression might provide some support for future target therapy trials.

Gene expression study of Aurora-A reveals implication during bladder carcinogenesis and increasing values in invasive urothelial cancer

OBJECTIVES

Urothelial carcinoma is a frequent and aggressive cancer. We wanted to gain better insight into the early molecular mechanisms of bladder carcinogenesis by evaluating Aurora-A gene expression, which is implicated in genomic stability and essential for mitosis.

MATERIALS

This study, using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), analyzed the expression levels of three selected genes in dissected tissues from normal bladder, noninvasive cancers, and muscle-invasive bladder carcinomas (n = 49). We compared gene expression levels of three genes (Aurora-A, and as control uroplakin II (UPII) and TBP, respectively) at different stages of bladder cancer. We used multivariate analysis, receiver operating characteristic curves and the nonparametric Mann-Whitney test.

RESULTS

The expression of Aurora-A gene studied was significantly deregulated, with an increasing level in cancer versus normal tissue Aurora-A. This development was linear. Aurora-A was already deregulated in early stages of carcinogenesis (pTa/pT1) (P = 0.0004) and displayed even more deregulation in muscle-invasive stages (pT2 to pT4). Immunohistochemistry performed on the same samples using Aurora-A antibody confirmed results of RT-PCR, with statistically significant values when comparing m-RNA expression and immunohistochemical values (P = 0.0001).

CONCLUSIONS

This study highlights the fact that Aurora-A gene expression is already strongly deregulated in early stages of urothelial carcinoma with abnormal expression, and might be considered a biomarker of tumor aggression. The increase in Aurora-A expression might provide further information regarding the behavior of bladder cancer in daily practice.

Expression of chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI) in bladder transitional cell carcinoma

OBJECTIVES

An analysis of differentially expressed genes (DEGs) between bladder transitional cell carcinoma (TCC) and the surrounding urothelium to help identify what lies behind the mechanism of multifocal tumor development has not yet been performed. We sought to find a new DEG related to the development of bladder TCC.

METHODS

Thirty-nine bladder TCC tissues paired with normal-appearing urothelium tissues obtained from the same patient were used as subjects. Initially, we compared the messenger RNA (mRNA) profiles between normal-appearing urothelium and TCC tissue of 1 patient by using annealing control primer (ACP)-based GeneFishing polymerase chain reaction (PCR) and selective amplification of family members (SAFM) PCR to identify potential DEGs. To validate the results of the ACP data, reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on those of all 39 patients.

RESULTS

Among the several DEGs discovered in the ACP data, 1 DEG was chosen as the candidate for the RT-PCR, that is present or markedly upregulated in normal-appearing urothelial tissue compared with TCC tissue. Gene sequence searching revealed that this DEG is chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI). Downregulation of COUP-TFI mRNA expression in TCC tissue compared to normal-appearing urothelium tissue of the same patient, irrespective of tumor stage and grade, was confirmed by RT-PCR in 39 patients.

CONCLUSIONS

Our results suggest that the loss of COUP-TFI may play a role in the transition from normal epithelium to TCC. Further characterization of the COUP-TFI gene is expected to give us informations about bladder TCC tumorigenesis.

Potential of urinary biomarkers in early bladder cancer diagnosis

Carcinoma of urinary bladder ranks among the top ten most common cancers worldwide. Approximately 80% of the disease is superficial (limited to mucosa and lamina propria) at the time of presentation. However, the majority of these tumors recur and 15-20% progress into muscle-invasive disease. Cystoscopic surveillance of the urinary bladder remains the standard of care to identify these recurrences on follow-up. Not only is this an invasive procedure, but the sensitivity of cystoscopy can be as low as 70%, so there can be up to 30% of tumors that are missed. Urinary cytology, with recognized limitations, has been used as an adjunct to this procedure, pending discovery of alternate urinary biomarkers. In the past decade there has been tremendous advancement in producing urinary biomarkers for urinary bladder cancer research, reflecting advancements in genomics and proteomics. An ideal biomarker should be able to replace cystoscopic examination and be cost effective. Unfortunately, most of the identified protein or molecular biomarkers have failed this test. This article critically appraises the status of these urinary biomarkers in urinary bladder cancer, in addition to highlighting some of the difficulties in this research area.

Nucleic acid-based marker approaches to urologic cancers

There are numerous molecular modifications known to occur in cancer. New nucleic acid-based biomarkers provide a unique approach to patient management in urologic oncology. Malignant transformation of a normal cell requires a series of epigenetic and genetic changes or "hits." Epigenetics produced by deoxyribonucleic acid methylation, adding a methyl group to the fifth position of cytosine within CpG dinucleotides, are important players in deoxyribonucleic acid repair, genome instability, and regulation of chromatin structure. Genetic alterations in cancer can include mutations, chromosome deletions, insertions, amplifications, and translocations. In addition, the modifications of telomeres are critical to the maintenance of chromatin structure, transcription, and cell function in cancer. We review only nucleic acid-based molecular biomarkers in urologic oncology that can assist the clinician in establishing the diagnosis of disease, or that can predict the behavior of the disease or the patient's survival.

Urinary markers in the detection of bladder cancer: what's new?

PURPOSE OF REVIEW

Bladder cancer is one of the most common genitourinary malignancies and is a potentially life-threatening diagnosis. For many patients, however, the diagnosis of bladder cancer entails a lifetime of vigilant, costly, and invasive surveillance for recurrent and/or progressive disease. In the context of relative limitations of the current standard of cystoscopy and cytology, there has been burgeoning activity in the development of novel molecular urine-based markers for bladder cancer detection.

RECENT FINDINGS

A large number of candidate bladder cancer biomarkers have emerged as our understanding of the molecular pathogenesis of the disease has evolved. Many of these are in the relatively earlier phases of development but several have received the approval of the United States Food and Drug Administration for clinical use and are already being applied to patients in clinical practice.

SUMMARY

Urine-based markers for bladder cancer detection represent an area of substantial innovation and discovery with potentially profound scientific, clinical, and economic implications. As more of these tests become standardized and undergo evaluation in large multicenter trials, it is conceivable that a novel marker or panel of markers will emerge as a major enhancement to the current standard of care.

Toward critical evaluation of the role(s) of molecular biomarkers in the management of bladder cancer

Among genitourinary malignancies, bladder cancer is a common, potentially dangerous and exceedingly costly disease entity. Predicated on substantial gains in our understanding of the natural history and molecular biology of bladder cancer, recent years have seen an explosion of new applied technologies to aid clinicians in the management of bladder cancer. Herein we present a systematic overview of general conceptual issues and specific strategies of potential relevance to the clinical evaluation of patients with bladder cancer. A number of basic epidemiological issues provide the relevant background within which we should consider candidate biomarkers. Within this framework, we highlight a number of important recent research findings representative of the large number of candidate bladder cancer biomarkers that have emerged. With several markers already having obtained regulatory approval for clinical use, this topic is of clear relevance not only to researchers but also to the practicing physician. Bladder cancer is a common, costly, and potentially dangerous disease with the opportunity for significant technological inroads in the area of applied biomarkers. An appreciation of basic epidemiological considerations informs our consideration of the state of the art and identifies specific strategies amenable to further innovation.

Early bladder cancer: concept, diagnosis, and management

Recent evidence on molecular pathways helps us to understand the pathogenesis of bladder cancer. However, the molecular mechanisms of recurrence of the disease and progression into muscle-invasive disease are not fully understood. The diagnostic accuracy and specificity of innovative markers for detection of the disease currently available in the clinical setting are still far from the level where cystoscopy would not be needed. Although risk factors for progression to muscle-invasive disease have been identified, we still cannot predict accurately the clinical behavior of superficial bladder cancer. In this review article, we summarize recent evidence on molecular pathogenesis, risk factors for recurrence and progression, urine markers for detection, and treatments in superficial bladder cancer.

Antisense oligodeoxynucleotide therapy for bladder cancer: recent advances and future prospects

Despite remarkable progress in therapeutic options for the management of bladder cancer, it remains a challenge for urologists to achieve successful outcomes in the treatment of both superficial and invasive bladder cancers. In this review, recent advances in the field of antisense oligodeoxynucleotide therapy targeting several genes playing functionally important roles in the progression and recurrence of bladder cancer are summarized. Data showing the synergistic antitumor activities of antisense oligodeoxynucleotide therapy, combined with several treatments, including cytotoxic chemotherapy, radiation and other molecular targeting therapies, are also presented. Finally, the future direction of antisense oligodeoxynucleotide therapy in the therapeutic strategy of bladder cancer is discussed. These findings may help clarify the significance of antisense oligodeoxynucleotide therapy as an attractive alternative to conventional strategies.

Improved clonality analysis of multifocal bladder tumors by combination of histopathologic organ mapping, loss of heterozygosity, fluorescence in situ hybridization, and p53 analyses

The clonality status of multifocal bladder tumors is still controversially discussed with experimental evidence for both monoclonality and field cancerization. Methodologically, loss of heterozygosity (LOH) and genomic sequencing analyses are widely used in clonality analysis of malignant tumors. In the present study, we used LOH analysis and genomic sequencing in combination with fluorescence in situ hybridization (FISH) and extensive histopathologic whole-organ mapping to determine the clonal relationship of multifocal bladder cancer disease. Tissue sections (1 cm(2)) covering the entire urothelial lining were systematically dissected from 2 cystectomy specimens (cystectomy 1, no urothelial lesions, bladder infiltration by a leiomyosarcoma of the vaginal wall; cystectomy 2, multifocal pT3G3 tumors). The location of each sample was documented (bladder mapping). Urothelial cells were microdissected for LOH (chromosomes 9, 17p) and FISH analysis (CDKI2 (9p21), FACC (9q22), p53 (17p13.1), and centromeric probes for corresponding chromosome). Exons 5 to 9 of the p53 gene were sequenced in all tumor samples. No chromosomal alterations were detected in the cystectomy specimen without urothelial malignancies. The tumor-bearing bladder showed an increasing frequency of deletions with increasing malignancy of the investigated lesions. LOH analysis detected deletions only on chromosomes 9p and 17p. In contrast, FISH analysis revealed deletions of all investigated genes at chromosomes 9p, 9q, and 17p in all samples analyzed (preneoplastic and neoplastic tissue). An identical p53 mutation in codon 281 was found in all 7 analyzable tumor samples. Combination of molecular data with histopathologic bladder mapping suggested a monoclonal development of the multifocal lesions mostly via intraurothelial migration. Our data strengthen the results from recently published studies that patients with advanced urothelial carcinoma seem to have a monoclonal panurothelial disease in most cases. FISH showed a much higher sensitivity for detection of chromosomal losses than classical LOH analysis, especially in preneoplastic and small lesions. Combining 3 molecular approaches together with histopathologic organ mapping presents a valuable tool to determine the clonality status of multifocal bladder tumors.

Analysis of genetic events in 17p13 and 9p21 regions supports predominant monoclonal origin of multifocal and recurrent bladder cancer

Clonality was tested in 86 tumours from 25 patients with recurrent and multifocal superficial bladder transitional cell carcinomas (TCCs) using the analysis of TP53 mutations and of LOH in the 17p13 and 9p21 regions. Tumours from the majority of individuals showed either absence or presence of the same TP53 mutation and/or an identical LOH pattern, with the same allele lost in all tumours. Only two pairs of tumours from two patients had discordant findings, which were incompatible with monoclonality. Therefore, our results rather support the monoclonal model of development of highly recurrent superficial bladder TCCs.

Bladder carcinoma: understanding advanced and metastatic disease with potential molecular therapeutic targets

This article is an expert review of bladder cancer genetics focusing on genetic changes and their significance in the pathogenesis and progression of bladder transitional cell carcinoma, in particular, muscle-invasive disease. Alongside the relevant genetic markers and their products, new therapeutic targets and agents that are being developed are presented.

Molecular evidence supporting field effect in urothelial carcinogenesis

PURPOSE

Human urothelial carcinoma is thought to arise from a field change that affects the entire urothelium. Multifocality of urothelial carcinoma is a common finding at endoscopy and surgery. Whether these coexisting tumors arise independently or are derived from the same tumor clone is uncertain. Molecular analysis of microsatellite alterations and X-chromosome inactivation status in the cells from each coexisting tumor may further our understanding of urothelial carcinogenesis.

EXPERIMENTAL DESIGN

We examined 58 tumors from 21 patients who underwent surgical excision for urothelial carcinoma. All patients had multiple separate foci of urothelial carcinoma (two to four) within the urinary tract. Genomic DNA samples were prepared from formalin-fixed, paraffin-embedded tissue sections using laser-capture microdissection. Loss of heterozygosity (LOH) assays for three microsatellite polymorphic markers on chromosome 9p21 (IFNA and D9S171), regions of putative tumor suppressor gene p16, and on chromosome 17p13 (TP53), the p53 tumor suppressor gene locus, were done. X-chromosome inactivation analysis was done on the urothelial tumors from 11 female patients.

RESULTS

Seventeen of 21 (81%) cases showed allelic loss in one or more of the urothelial tumors in at least one of the three polymorphic markers analyzed. Concordant allelic loss patterns between each coexisting urothelial tumor were seen in only 3 of 21 (14%) cases. A concordant pattern of nonrandom X-chromosome inactivation in the multiple coexisting urothelial tumors was seen in only 3 of 11 female patients; of these 3 cases, only one displayed an identical allelic loss pattern in all of the tumors on LOH analysis.

CONCLUSION

LOH and X-chromosome inactivation assays show that the coexisting tumors in many cases of multifocal urothelial carcinoma have a unique clonal origin and arise from independently transformed progenitor urothelial cells, supporting the "field effect" theory for urothelial carcinogenesis.

Interpreting epithelial cancer biology in the context of stem cells: tumor properties and therapeutic implications

Over 90% of all human neoplasia is derived from epithelia. Significant progress has been made in the identification of stem cells of many epithelia. In general, epithelial stem cells lack differentiation markers, have superior in vivo and in vitro proliferative potential, form clusters in association with a specialized mesenchymal environment (the 'niche'), are located in well-protected and nourished sites, and are slow-cycling and thus can be experimentally identified as 'label-retaining cells'. Stem cells may divide symmetrically giving rise to two identical stem cell progeny. Any stem cells in the niche, which defines the size of the stem cell pool, may be randomly expelled from the niche due to population pressure (the stochastic model). Alternatively, a stem cell may divide asymmetrically yielding one stem cell and one non-stem cell that is destined to exit from the stem cell niche (asymmetric division model). Stem cells separated from their niche lose their stemness, although such a loss may be reversible, becoming 'transit-amplifying cells' that are rapidly proliferating but have a more limited proliferative potential, and can give rise to terminally differentiated cells. The identification of the stem cell subpopulation in a normal epithelium leads to a better understanding of many previously enigmatic properties of an epithelium including the preferential sites of carcinoma formation, as exemplified by the almost exclusive association of corneal epithelial carcinoma with the limbus, the corneal epithelial stem cell zone. Being long-term residents in an epithelium, stem cells are uniquely susceptible to the accumulation of multiple, oncogenic changes giving rise to tumors. The application of the stem cell concept can explain many important carcinoma features including the clonal origin and heterogeneity of tumors, the occasional formation of tumors from the transit amplifying cells or progenitor cells, the formation of precancerous 'patches' and 'fields', the mesenchymal influence on carcinoma formation and behavior, and the plasticity of tumor cells. While the concept of cancer stem cells is extremely useful and it is generally assumed that such cells are derived from normal stem cells, more work is needed to identify and characterize epithelial cancer stem cells, to address their precise relationship with normal stem cells, to study their markers and their proliferative and differentiation properties and to design new therapies that can overcome their unusual resistance to chemotherapy and other conventional tumor modalities.

The use of real-time PCR methods in DNA sequence variation analysis

BACKGROUND

Real-time (RT) PCR methods for discovering and genotyping single nucleotide polymorphisms (SNPs) are becoming increasingly important in various fields of biological sciences. SNP genotyping is widely used to perform genetic association studies aimed at characterising the genetic factors underlying inherited traits. The detection and quantification of somatic mutations is an important tool for investigating the genetic causes of tumorigenesis. In infectious disease diagnostics there is an increasing emphasis placed on genotyping variation within the genomes of pathogenic organisms in order to distinguish between strains.

METHODS

There are several platforms and methods available to the researcher wishing to undertake SNP analysis using real-time PCR methods. These use fluorescent technologies for discriminating between the alternate alleles of a polymorphism. There are several real-time PCR platforms currently on the market. Two of the key technical challenges are allele discrimination and allele quantification.

CONCLUSIONS

Applications of this technology include SNP genotyping, the sensitive detection of somatic mutations and infectious disease subtyping.

Phase I trial of intravesical Suramin in recurrent superficial transitional cell bladder carcinoma

Suramin is an antitrypanosomal agent with antineoplastic activity, but with serious systemic side effects. We administered Suramin intravesically to determine a concentration with low toxicity but with evidence of a pharmacodynamic effect, to recommend a dose level for phase II trials. This was an open-labelled, nonrandomised dose-escalation phase I study. In all, 12 patients with a history of recurrent superficial bladder cancer were grouped into four dose levels (10–150 mg ml⁻¹ in 60 ml saline). Six catheter instillations at weekly intervals were used. Cystoscopy and biopsy were performed before and 3 months after the start of treatment. Suramin was assayed using high-performance liquid chromatography, vascular endothelial growth factor (VEGF) using ELISA (enzyme-linked immunosorbent assay), and urinary protein profile using surface-enhanced laser desorption ionisation mass spectroscopy (SELDI). Minimal systemic absorption of Suramin was found at the highest dose of 150 mg ml⁻¹. Urinary VEGF was affected by Suramin at doses above 50 mg ml⁻¹, corresponding to the estimated threshold of saturation of Suramin binding to urine albumin. SELDI showed a specific disappearance of urinary protein peaks during treatment. Intravesical Suramin shows lack of toxicity and low systemic absorption. The results of this phase I trial support expanded clinical trials of efficacy at a dose of 100 mg ml⁻¹ intravesically.

Androgen receptor expression is inversely correlated with pathologic tumor stage in bladder cancer

OBJECTIVES

To evaluate the expression of the androgen receptor (AR) in transitional cell carcinoma (TCC) of the bladder, and to assess whether its expression correlated with pathologic tumor stage. TCC of the bladder is three times more common in males than in females. The origin of this sex difference in incidence is unknown.

METHODS

We evaluated tumor specimens from 49 consecutive patients treated for TCC of the bladder at our institution between July 2002 and June 2003. Immunohistochemistry was performed using a monoclonal mouse anti-AR antibody on paraffin-embedded tissue sections of tumors obtained from transurethral resection, radical cystectomy, or resection of metastases. Specimens were assessed for AR expression, and, in tumors that demonstrated AR staining, the percentage of nuclei that stained positive was recorded.

RESULTS

Of the 49 tumors, 26 (53.1%) expressed the AR. The percentage of tumors that expressed the AR decreased with increasing pathologic stage, from 88.9% of pTa lesions to 0% of pT3 tumors. Overall, 75% of superficial tumors (pTa + pT1 + carcinoma in situ) expressed the AR compared with 21.4% of invasive tumors (pT2 + pT3; P = 0.002). In addition, among AR-expressing tumors, the mean percentage of nuclei that stained positive for the AR was significantly greater in pTa tumors (62.5%) than in pT1 (31%) or pT2 (20%) tumors (P = 0.005).

CONCLUSIONS

We found a decrease in AR protein expression in tumors with increased pathologic stage. Our data suggest that the loss of AR expression is associated with invasive bladder cancer.

Risk factors for subsequent development of bladder cancer after primary transitional cell carcinoma of the upper urinary tract

OBJECTIVES

To determine the independent risk factors for intravesical tumor recurrence in patients with primary transitional cell carcinoma of the upper urinary tract, and to develop a risk-stratification model to allow more accurate prediction of recurrence risk.

METHODS

Of 141 patients who underwent total nephroureterectomy for clinically localized transitional cell carcinoma of the upper urinary tract, the data from 89 patients were retrospectively reviewed. Patients with a previous history or concomitance of bladder cancer and/or a follow-up period of less than 1 year were excluded from this study. Multivariate analysis by Cox's proportional hazards model was used to determine independent risk factors for intravesical tumor recurrence.

RESULTS

Of 89 patients, 37 (41.6%) experienced subsequent intravesical tumor recurrence during a median follow-up period of 39.7 months (range 12.0 to 186.6). On multivariate analysis, tumor multiplicity, pathologic stage, tumor size, and surgical modality had a statistically significant impact on the risk of intravesical tumor recurrence (P = 0.0075, P = 0.0221, P = 0.0377, and P = 0.0413, respectively). Pathologic stage and tumor size were inversely correlated to the risk. A scoring system for the risk of intravesical recurrence was developed from the proposed prognostic factors, and the patients were stratified into three groups according to their scores, with statistically significant prognostic differences between them (P = 0.0018).

CONCLUSIONS

Tumor multiplicity, pathologic stage, tumor size, and surgical modality all had a significant impact on the incidence of intravesical tumor recurrence. A risk stratification model constructed from tumor biologic factors may be useful in the follow-up of patients with transitional cell carcinoma of the upper urinary tract.

Molecular markers for predicting recurrence, progression and outcomes of bladder cancer (do the poster boys need new posters?)

PURPOSE OF REVIEW

Molecular markers for bladder cancer recurrence and progression continue to drive many research programmes. Translating the laboratory findings into the clinical environment where these markers are used in clinical decision making has proved problematic. In the clinical arena, stage and grade are still the main focus for decisions about patient management. There is however an evolution in bladder cancer research from single-marker/single-pathway research to a more global assessment of the tumour cell with DNA microarrays and proteomics.

RECENT FINDINGS

In the last year, DNA microarray assessment has revealed several interesting molecular markers such as p33ING1 and DEK. Parallel "conventional" single-pathway research has focused on new novel markers such as HER2/neu, survivin and matrix metalloproteinase 2 (MMP-2). Molecular markers that have a long-standing association with bladder cancer progression such as p53, E-cadherin and Ki-67 have been reviewed by both single-marker studies and by microarray studies and their status remains important.

SUMMARY

It is an exciting time in the molecular biology research of bladder cancer as the focus changes to assess the global genetic and protein expression within tumour cells. From such a wealth of information it is likely that molecular markers will make the translation from benchside to bedside.

High-Density Single Nucleotide Polymorphism Array Defines Novel Stage and Location-Dependent Allelic Imbalances in Human Bladder Tumors

Bladder cancer is a common disease characterized by multiple recurrences and an invasive disease course in more than 10% of patients. It is of monoclonal or oligoclonal origin and genomic instability has been shown at certain loci. We used a 10,000 single nucleotide polymorphism (SNP) array with an average of 2,700 heterozygous SNPs to detect allelic imbalances (AI) in 37 microdissected bladder tumors from 17 patients. Eight tumors represented upstaging from Ta to T1, eight from T1 to T2+, and one from Ta to T2+. The AI was strongly stage-dependent as four chromosomal arms showed AI in &gt; 50% of Ta samples, eight in T1, and twenty-two in T2+ samples. The tumors showed stage-dependent clonality as 61.3% of AIs were reconfirmed in later T1 tumors and 84.4% in muscle-invasive tumors. Novel unstable chromosomal areas were identified at chromosomes 6q, 10p, 16q, 20p, 20q, and 22q. The tumors separated into two distinct groups, highly stable tumors (all Ta tumors) and unstable tumors (2/3 muscle-invasive). All 11 unstable tumors had lost chromosome 17p areas and 90% chromosome 8 areas affecting Netrin-1/UNC5D/MAP2K4 genes as well as others. AI was present at the TP53 locus in 10 out of 11 unstable tumors, whereas 6 had homozygous TP53 mutations. Tumor distribution pattern reflected AI as seven out of eight patients with additional upper urinary tract tumors had genomic stable bladder tumors (P &lt; 0.05). These data show the power of high-resolution SNP arrays for defining clinically relevant AIs.