Epidemiology of urinary bladder cancer: from tumor development to patient’s death

Bladder cancer: a simple model becomes complex

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

MR imaging of urinary bladder carcinoma and beyond

Detection of muscle invasion is a critical aspect in management of urinary bladder cancer. MR imaging has the potential and promise of delivering this premise noninvasively. This article reviews the current status of MR imaging in evaluation of bladder cancer. Also discussed are other important neoplastic and nonneoplastic conditions affecting the bladder.

Metastatic Bladder Cancer Presenting with Persistent Hematuria in Young Man with Cystic Fibrosis

We report a case of metastatic bladder cancer developing in a young man with cystic fibrosis (CF) that was initially diagnosed as ureterolithiasis and managed as renal colic. With the improved survival of patients with CF, an increasing burden of extrapulmonary disease manifestations is apparent. Renal colic is observed at an increased frequency in patients with CF relative to the general population and is a commonly recognized cause of hematuria. However, CF patients harboring a malignancy are recognized to be at increased risk of delayed identification owing to atypical symptoms and lack of demographic risk factors. This case illustrates how investigations to rule out malignancy are warranted in those CF patients not responding to therapies directed towards presumptive diagnoses.

Emerging roles of cadmium and heme oxygenase in type-2 diabetes and cancer susceptibility

Many decades after an outbreak of severe cadmium poisoning, known as Itai-itai disease, cadmium continues to pose a significant threat to human health worldwide. This review provides an update on the effects of this environmental toxicant cadmium, observed in numerous populations despite modest exposure levels. In addition, it describes the current knowledge on the link between heme catabolism and glycolysis. It examines novel functions of heme oxygenase-2 (HO-2) that protect against type 2-diabetes and obesity, which have emerged from diabetic/obese phenotypes of the HO-2 knockout mouse model. Increased cancer susceptibility in type-2 diabetes has been noted in several large cohorts. This is a cause for concern, given the high prevalence of type-2 diabetes worldwide. A lifetime exposure to cadmium is associated with pre-diabetes, diabetes, and overall cancer mortality with sex-related differences in specific types of cancer. Liver and kidney are target organs for the toxic effects of cadmium. These two organs are central to the maintenance of blood glucose levels. Further, inhibition of gluconeogenesis is a known effect of heme, while cadmium has the propensity to alter heme catabolism. This raises the possibility that cadmium may mimic certain HO-2 deficiency conditions, resulting in diabetic symptoms. Intriguingly, evidence has emerged from a recent study to suggest the potential interaction and co-regulation of HO-2 with the key regulator of glycolysis: 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4 (PFKFB4). HO-2 could thus be critical to a metabolic switch to cancer-prone cells because the enzyme PFKFB and glycolysis are metabolic requirements for cell proliferation and resistance to apoptosis.

Accurate risk assessment of patients with asymptomatic hematuria for the presence of bladder cancer

PURPOSE

Bladder cancer is frequently diagnosed during a workup for hematuria. However, most patients with microscopic hematuria and many with gross hematuria are not appropriately referred to urologists. We hypothesized that in patients presenting with asymptomatic hematuria the risk of having bladder cancer can be predicted with high accuracy. Toward this end, we analyzed risk factors in patients with asymptomatic hematuria and developed a nomogram for the prediction of bladder cancer presence.

METHODS

Data from 1,182 consecutive subjects without a history of bladder cancer undergoing initial evaluation for asymptomatic hematuria were collected at three centers. Clinical risk factors including age, gender, smoking status, and degree of hematuria were recorded. All subjects underwent standard workup including voided cytology, upper tract imaging, and cystourethroscopy. Factors associated with the presence of bladder cancer were evaluated by univariable and multivariable logistic regression analyses. The multivariable analysis was used to construct a nomogram. Internal validation was performed using 200 bootstrap samples.

RESULTS

Of the 1,182 subjects who presented with asymptomatic hematuria, 245 (20.7 %) had bladder cancer. Increasing age (OR = 1.03, p < 0.0001), smoking history (OR = 3.72, p < 0.0001), gross hematuria (OR = 1.71, p = 0.002), and positive cytology (OR = 14.71, p < 0.0001) were independent predictors of bladder cancer presence. The multivariable model achieved 83.1 % accuracy for predicting the presence of bladder cancer.

CONCLUSIONS

Bladder cancer presence can be predicted with high accuracy in patients who present with asymptomatic hematuria. We developed a nomogram to help optimize referral patterns (i.e., timing and prioritization) of patients with asymptomatic hematuria.

Pretreatment parameters obtained from peripheral blood sample predicts invasiveness of bladder carcinoma

PURPOSE

To predict the invasiveness of urothelial bladder carcinoma using a logistic regression model on preoperative peripheral blood samples.

PATIENTS AND METHODS

Hospital data of patients operated for urothelial carcinoma were reviewed retrospectively. Preoperative blood samples were collected before the first cystoscopic examination. Any kind of infection or inflammation was an exclusion criterion. Patients were grouped as having a non-muscle-invasive or muscle-invasive urothelial carcinoma. The mean age was 69 years and was determined as the cut-off value. According to receiver operating characteristic curves, threshold points were determined for lymphocytes, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), thrombocytes and mean platelet volume. Demographic specialties, parameters obtained from blood samples, tumor size and multiplicity were evaluated and significant parameters were put into a logistic regression model.

RESULTS

The study group consisted of 80 non-muscle-invasive and 102 muscle-invasive patients. Age (≤69 vs. >69), female gender, NLR (2.57), mean platelet volume (7.9/fl) and platelet count (400,000/µl) were significant parameters and put in a model. Using odds ratios, the probability of tumor invasiveness was calculated by a formula.

CONCLUSION

Age, female gender, NLR and platelet count were found to be the predictors of invasiveness of urothelial carcinoma.

Association of p53 Arg72Pro polymorphism with bladder cancer: a meta-analysis

BACKGROUND

p53 tumor suppressor gene Arg72Pro polymorphism has been associated with bladder cancer. However, results were inconsistent. We performed this meta-analysis to estimate the association between p53 Arg72Pro polymorphism and bladder cancer.

METHODS

Electronic search of PubMed was conducted to select studies. Studies containing available genotype frequencies of Arg72Pro were chosen, and pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the association.

RESULTS

The final meta-analysis included 14 published studies with 2176 bladder cancer cases and 2798 controls. The results suggested that the variant genotype was associated with the bladder cancer risk (additive model: OR=1.72, 95% CI: 1.036-1.325, P=0.011; dominant model: OR=1.268, 95% CI: 1.003-1.602, P=0.047) in Asian subgroup. However, the association was not significant between this polymorphism and bladder cancer risk in Caucasian (additive model: OR=0.773, 95% CI: 0.564-1.059, P=0.109; dominant model: OR=0.685, 95% CI: 0.418-1.124, P=0.134).

CONCLUSION

This meta-analysis suggests that p53 Arg72Pro polymorphism is associated with increased risk of bladder cancer in Asians. To validate the association between this polymorphism and bladder cancer, further studies with larger participants worldwide are needed.

Meta-analysis demonstrates lack of association of the hOGG1 Ser326Cys polymorphism with bladder cancer risk

The functional polymorphism Ser326Cys (rs1052133) in the human 8-oxoguanine DNA glycosylase (hOGG1) gene has been implicated in bladder cancer risk. However, reports of this association between the Ser326Cys polymorphism and bladder cancer risk are conflicting. In order to help clarify this relationship, we made a meta-analysis of seven case-control studies, summing 2521 cases and 2408 controls. We used odds ratios (ORs) with 95% confidence intervals (95%CIs) to assess the strength of the association. Overall, no significant association between the hOGG1 Ser326Cys polymorphism and bladder cancer risk was found for Cys/Cys vs Ser/Ser (OR = 1.10, 95%CI = 0.74-1.65), Ser/Cys vs Ser/Ser (OR = 1.07, 95%CI = 0.81-1.42), Cys/Cys + Ser/Cys vs Ser/Ser (OR = 1.08, 95%CI = 0.87-1.33), and Cys/Cys vs Ser/Cys + Ser/Ser (OR = 1.04, 95%CI = 0.65-1.69). Even when stratified by ethnicity, no significant association was observed. We concluded that the hOGG1 Ser326Cys polymorphism does not contribute to susceptibility to bladder cancer.

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.

Exposure of primary porcine urothelial cells to benzo(a)pyrene: in vitro uptake, intracellular concentration, and biological response

More than 90 % of all bladder cancers are transitional cell carcinomas arising from the cells lining the inside of the hollow organ (uroepithelium). Cell cultures from primary urinary bladder epithelial cells (PUBEC) of pigs were established to assess the uptake, intracellular concentration, and subcellular distribution of the environmental pollutant benzo(a)pyrene (BaP). During treatment of the cells with 0.5 μM BaP for up to 24 h, intracellular concentration of BaP increased without saturation but with marked differences between various PUBEC pools. Analysis of BaP uptake by laser scanning microscopy indicated that BaP is rapidly partitioned into the cell membrane, while only a slight but significant increase in BaP fluorescence intensity was observed in the cytosol and nucleus. Spectrofluorometric quantification of BaP in PUBEC using ex situ calibration revealed a strong accumulation of BaP, leading to intracellular concentrations ranging from 7.28 to 35.70 μM in cells exposed to 0.5 μM BaP and from 29.9 to 406.64 μM in cells exposed to 10 μM BaP. These results were confirmed by gas chromatographic mass spectrometric analysis. Apoptotic cell nuclei were assessed by TUNEL analysis to see whether BaP exposure at the given concentrations results in a toxic effect. While apoptotic cells were barely detectable in control epithelial cells, there was a marked elevation in apoptosis in the BaP-exposed cells. In conclusion, a comprehensive study on uptake and quantification of BaP in epithelial cells from pig bladder is reported for the first time. The study may be helpful in understanding the pattern of BaP uptake and distribution in bladder and its possible implication in bladder cancer development.

miR-96 regulates FOXO1-mediated cell apoptosis in bladder cancer

Transitional cell carcinoma (TCC) is one of the most common types of malignancies and a leading cause of genitourinary system cancer mortality worldwide. The tumor suppressor gene FOXO1, a member of the forkhead box O (FOXO) subfamily of transcription factors, is downregulated in a number of cancers, including TCC; however, the underlying mechanisms are poorly understood. In the present study, we used microRNA (miRNA) target prediction algorithms to identify a conserved potential miR-96 binding site in the 3'-untranslated region (3'-UTR) of FOXO1. Using quantitative real-time PCR (qRT-PCR) and northern blot analysis, we identified that miR-96 was downregulated in TCC tissues compared to normal bladder tissues (NB), suggesting that the loss of FOXO1 expression in TCC may be mediated by miR-96. To confirm this, we transfected pre-miR-96/anti-miR-96 into the T24 TCC cell line and revealed that miR-96 expression was sufficient to significantly reduce FOXO1 expression. Conversely, FOXO1 expression was not completely restored by the inhibition of miR-96 in T24 cells. Moreover, RNA silencing of FOXO1 significantly reduced miR-96 inhibitor-mediated T24 cell apoptosis. In conclusion, our study demonstrates that the miR-96 targeting of FOXO1 is upregulated in TCC; in addition, TCC tumorigenesis may be partly due to the ability of miR-96 to promote FOXO1 repression, thereby bypassing cell apoptosis controls.

hOGG1 Ser326Cys polymorphism is associated with risk of bladder cancer in a Chinese population: a case-control study

Human oxoguanine glycosylase 1 (hOGG1) is a DNA repair enzyme, which plays important roles in the base excision repair (BER) pathway. Several studies reported a common polymorphism Ser326Cys (rs1052133) in hOGG1, which conferred the susceptibility of bladder cancer. We hypothesized that the polymorphism is associated with risk of bladder cancer in a Chinese population. In a case-control study of 1050 histologically confirmed bladder cancer patients and 1404 age and sex matched healthy controls, we genotyped the hOGG1 Ser326Cys polymorphism using TaqMan technology and assessed its association with bladder cancer risk. We found that the hOGG1 Ser/Cys + Ser/Ser genotypes were associated with a significantly increased risk of bladder cancer (adjusted odds ratio [OR] = 1.19, 95% confidence interval [CI] = 1.01-1.41), compared with the Cys/Cys genotype. Furthermore, the increased risk was more pronounced among subjects over age 65 years (OR = 1.31, 95% CI = 1.04-1.66), male subjects (OR = 1.21, 95% CI = 1.00-1.47), ever smokers (OR = 1.29, 95% CI = 1.00-1.68) and heavy smokers (>20 pack-years) (OR = 1.45, 95% CI = 1.03-2.04). No significant association was observed in the stratification of tumor grade and tumor stage for bladder cancer. In conclusion, our results suggest that hOGG1 Ser326Cys polymorphism may contribute to the susceptibility to bladder cancer in a Chinese population.

The association of cruciferous vegetables intake and risk of bladder cancer: a meta-analysis

OBJECTIVE

This meta-analysis of cohort and case-control studies was undertaken to evaluate the relationship between cruciferous vegetables intake and risk of bladder cancer.

METHODS

Eligible studies were retrieved via both computer searches and review of references. The summary relative risks (RRs) with 95% confidence interval (CI) for the highest versus the lowest intake of cruciferous vegetables were calculated. Heterogeneity and publication bias were also evaluated.

RESULTS

Five cohort and five case-control studies were included. A significantly decreased risk with bladder cancer was observed in overall cruciferous vegetables intake group (RR = 0.80; 95% CI 0.69-0.92) and subgroup of case-control studies (RR = 0.78; 95% CI, 0.67-0.89), but not in cohort studies (RR = 0.86; 95% CI, 0.61-1.11). No heterogeneity and publication bias were detected across studies.

CONCLUSION

Our findings support that cruciferous vegetables intake was related to the decreased risk of bladder cancer. Because of the limited number of studies, further well-designed prospective studies are needed to explore the protective effect of cruciferous vegetables on bladder cancer.

Milk and dairy consumption and risk of bladder cancer: a meta-analysis

OBJECTIVE

To explore potential relations between the intake of milk or dairy products and the risk of bladder cancer.

METHODS

Eligible studies published up to May 2011 were retrieved via both computer searches and manual review of references. Random-effects models were used to calculate summary relative risk estimates (SRRE) based on high-contrast to low-intake values. Sensitivity and influence analyses were conducted, and heterogeneity among study results was explored through stratified analyses by study design, gender, geographic region, year of publication, or whether or not adjustment for several confounders (ie, age, gender, body mass index, smoking, and total energy intake).

RESULTS

We extracted data from 14 studies on milk (involving 4879 cases) and 6 studies on dairy products (3087 cases). The total study population was up to 324,241 individuals. Overall, there was no significant association between milk intake and bladder cancer (SRRE 0.89, 95% CI 0.77-1.02). However, an inverse association was found in the United States (SRRE 0.88, 95% CI .79-.99). In addition, no significant association was observed between consumption of dairy products and risk of bladder cancer (SRRE 0.95, 95% CI .71-1.27), though an inverse association was detected in the Japanese population (SRRE 0.56, 95% CI .40-.80).

CONCLUSION

There appears to be enough evidence to support the null hypothesis. The overall result was not statistically significant. The findings of this meta-analysis are not supportive of an independent relationship between the intake of milk or dairy products and the risk of bladder cancer. However, these findings are based on limited research. Further efforts should be made to confirm these findings.

Comparison of DNA damage in human-derived hepatoma line (HepG2) exposed to the fifteen drinking water disinfection byproducts using the single cell gel electrophoresis assay

Disinfection of drinking water reduces pathogenic infection, but generates disinfection by-products (DBPs) in drinking water. In this study, the effect of fifteen DBPs on DNA damage in human-derived hepatoma line (HepG2) was investigated by the single cell gel electrophoresis (SCGE) assay. These fifteen DBPs are: four trihalomethanes (THMs), six haloacetic acides (HAAs), three haloacetonitriles (HANs), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), and chloral hydrate (CH). Based on the minimal effective concentration (MEC) at which DBPs induced significant increase in olive tail moment (OTM), the rank order of DNA-damaging potency is: bromodichloromethane (BDCM)>dibromochloromethane (DBCM)>tribromomethane (TBM)>trichloromethane (TCM) of the four THMs; iodoacetic acid (IA)>bromoacetic acid (BA)>dibromoacetic acid (DBA)>dichloracetic acid (DCA)>trichloroacetic acid (TCA) of the five HAAs; dibromoacetonitrile (DBN)approximately dichloroacetonitrile (DCN)>trichloroacetonitrile (TCN) of the three HANs. The DNA damaging potency of MX and CH is similar to TCA and DCA, respectively. IA is the most genotoxic DBP in the fifteen DBPs, followed by BA. Chloroacetic acid (CA) is not genotoxic in this assay. Our findings indicated that HepG2/SCGE is a sensitive tool to evaluate the genotoxicity of DBPs and iodinated DBPs are more genotoxic than brominated DBPs, but chlorinated DBPs are less genotoxic than brominated DBPs.

Bladder cancer survival in a former industrial area in Saxony-Anhalt, Germany

Long-term follow-ups on bladder cancer patients from highly industrialized areas are rare. Therefore, we present a follow-up of bladder cancer patients from the greater area Lutherstadt Wittenberg, a center of the chemical industry of the former German Democratic Republic. Relapse-free survival times of 213 confirmed bladder cancer cases from the greater area Lutherstadt Wittenberg were collected between 2008 and 2009. Data on lifestyle and occupational exposure to potential carcinogens was recorded by questionnaire. Genotypes of N-acetyltransferase 2 (NAT2), glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), rs710521, and rs9642880 were determined by standard methods. Cox models were used to evaluate differences in relapse-free survival. Clear differences in relapse-free survival could be observed for the number of relapses, multilocular tumor growth, and relapses with higher staging or grading than the primary tumor, as well as GSTT1. None of the other investigated polymorphisms showed significant impact on prognosis. This is the first study on two recently detected single-nucleotide polymorphisms (SNPs) showing that these polymorphisms may also contribute to shorter relapse-free times.

Lack of association between hOGG1 Ser326Cys polymorphism and the risk of bladder cancer: a meta-analysis

OBJECTIVE

In some but not all studies, hOGG1 Ser326Cys polymorphism has been reported to contribute to the risk of bladder cancer. To determine whether there is a significant association of hOGG1 Ser326Cys polymorphism with the susceptibility for bladder cancer, we performed a comprehensive meta-analysis.

METHODS

The electronic PubMed, Medline and Springer databases were searched for publications on the association between hOGG1 Ser326Cys polymorphism and bladder cancer through to May 20, 2011. Seven case-control studies were identified, including 2,474 cases and 2,408 controls. From these identified publications, crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of association using fixed- or random-effects models. Two investigators each extracted data and conducted the analysis independently.

RESULTS

Overall, no significant associations were found between hOGG1 Ser326Cys polymorphism and bladder cancer in codominant models (GG vs. CC: OR 1.11, 95% CI 0.74-1.66, p = 0.63; GC vs. CC: OR 1.07, 95% CI 0.80-1.41, p = 0.65). Similarly, no significant associations with bladder cancer were observed in the recessive model (GG vs. GC+CC: OR 1.05, 95% CI 0.65-1.70, p = 0.85), dominant model (GG+GC vs. CC: OR 1.07, 95% CI 0.87-1.32, p = 0.53) and allele model (G vs. C: OR 1.06, 95% CI 0.90-1.26, p = 0.49). In the stratified analyses by ethnicity, control sources, pathology, Hardy-Weinberg equilibrium, significant associations were still not observed.

CONCLUSIONS

The overall current literature on hOGG1 Ser326Cys polymorphism and the risk of bladder cancer suggests no statistically significant association between the two. Additional primary studies may be necessary to provide evidence of any significant association between this specific polymorphism and bladder cancer.

Urinary bladder cancer risk factors in Egypt: a multicenter case-control study

BACKGROUND

We investigated associations between tobacco exposure, history of schistosomiasis, and bladder cancer risk in Egypt.

METHODS

We analyzed data from a case-control study (1,886 newly diagnosed and histologically confirmed cases and 2,716 age-, gender-, and residence-matched, population-based controls). Using logistic regression, we estimated the covariate-adjusted ORs and 95% confidence interval (CI) of the associations.

RESULTS

Among men, cigarette smoking was associated with an increased risk of urothelial carcinoma (OR = 1.8; 95% CI, 1.4-2.2) but not squamous cell carcinoma (SCC); smoking both water pipes and cigarettes was associated with an even greater risk for urothelial carcinoma (OR = 2.9; 95% CI, 2.1-3.9) and a statistically significant risk for SCC (OR = 1.8; 95% CI, 1.2-2.6). Among nonsmoking men and women, environmental tobacco smoke exposure was associated with an increased risk of urothelial carcinoma. History of schistosomiasis was associated with increased risk of both urothelial carcinoma (OR = 1.9; 95% CI, 1.2-2.9) and SCC (OR = 1.9; 95% CI, 1.2-3.0) in women and to a lesser extent (OR = 1.4; 95% CI, 1.2-1.7 and OR = 1.4; 95% CI, 1.1-1.7, for urothelial carcinoma and SCC, respectively) in men.

CONCLUSIONS

The results suggest that schistosomiasis and tobacco smoking increase the risk of both SCC and urothelial carcinoma.

IMPACT

This study provides new evidence for associations between bladder cancer subtypes and schistosomiasis and suggests that smoking both cigarettes and water pipes increases the risk for SCC and urothelial carcinoma in Egyptian men.

Milk consumption and bladder cancer risk: a meta-analysis of published epidemiological studies

Studies investigating the association of milk consumption with bladder cancer risk have reported inconsistent findings. We conducted a meta-analysis of published cohort and case-control studies to pool the risk estimates of the association between milk intake and bladder cancer. We quantified associations with bladder cancer using meta-analysis of odds ratio (OR) associated with the highest vs. the lowest category of milk intake using fixed- or random-effect models depending on the heterogeneity of effects among studies. Nineteen cohort and case-control studies were eligible for inclusion. High milk intake was significantly associated with decreased risk of bladder cancer (OR, 0.84; 95% CI, 0.71-0.97) when comparing the highest with the lowest category of milk intake. The inverse association was stronger in Asia (OR, 0.60; 95% CI, 0.40-0.81) than North America (OR, 0.89; 95% CI, 0.76-1.03), and no association was observed in Europe (OR, 1.05; 95% CI, 0.85-1.26). This relationship also varied significantly by specific dairy products. Our results suggest that milk may be related to the reduction of bladder cancer risk. Further studies need to clarify the biological mechanisms.

Repeated white light transurethral resection of the bladder in nonmuscle-invasive urothelial bladder cancers: systematic review and meta-analysis

BACKGROUND AND PURPOSE

Transurethral resection of the bladder (TURB), the first step in treatment of patients with urothelial bladder cancers, is limited by technicalities, surgeon skill, and random chance. When high-risk superficial diseases are discovered, a repeated TURB is indicated. We reviewed current literature and performed a meta-analysis of the role of repeated TURB in the management of nonmuscle-invasive bladder cancers.

METHODS

PubMed, MEDLINE, ISI Web of Knowledge, EBSCO, EMBASE, and Biomed Central databases were searched for reports in English from 1980 to June 2010. The end point was prevalence of persistent urothelial bladder cancer of any stage and grade at repeated TURB, assessed separately for T(a) and T(1) lesions at TURB. Persistence was presence at repeated TURB of same or lower stage cancer as at TURB; upstaging was presence of higher stage.

RESULTS

There were 2327 original articles and 562 reviews retrieved. Data from 15 studies were pooled and analyzed. Prevalence of T(1) was reported in all and of T(a) in 8. Persistence rate prevalence at repeated TURB was 0.39 (95% confidence interval [CI]=0.26 to 0.54) for T(a) and 0.47 (95% CI=0.41 to 0.53) for T(1). Persistence was 19.4% to 56% and 15.2% to 55%, and upstaging occurred in 0% to 14.3% of T(a) and 0% to 24.4% of T(1) at repeated TURB, respectively.

CONCLUSION

High percentages of persistence and upstaging confirm a repeated TURB is needed in patients with high-risk nonmuscle-invasive bladder cancer. Further investigation is encouraged taking risk stratification into consideration to evaluate the role of repeated TURB in low- and mid- risk diseases.

Uropathogenic bacteria leave a mark

Urinary tract infections are common, obnoxious and in some cases even life endangering. They are most often caused by uropathogenic Escherichia coli. Persistent and seemingly recurrent infections may be caused by bacteria establishing intracellular reservoirs in the urothelial epithelium. A better understanding of the mechanisms involved in the complex interplay between host and pathogens is required for preventing and controlling these infections. A paper in this issue of Laboratory Investigation reports changes in gene expression in urothelial carcinoma cells following infection by uropathogenic bacteria which go along with the activation of DNA methyltransferase 1 and increased methylation at the CDKN2A gene. These pioneer findings should stimulate the further development of in vitro models for studying urothelial infections and prompt more extensive analyses of epigenetic alterations elicited by bacterial infections in the urinary tract.

Lower risk in parous women suggests that hormonal factors are important in bladder cancer etiology

BACKGROUND

Urinary bladder cancer is two to four times more common among men than among women, a difference in risk not fully explained by established risk factors. Our objective was to determine whether hormonal and reproductive factors are involved in female bladder cancer.

METHODS

We analyzed data from two population-based studies: the Los Angeles-Shanghai Bladder Cancer Study, with 349 female case-control pairs enrolled in Los Angeles and 131 female cases and 138 frequency-matched controls enrolled in Shanghai, and the California Teachers Study (CTS), a cohort of 120,857 women with 196 incident cases of bladder urothelial carcinoma diagnosed between 1995 and 2005. We also conducted a meta-analysis summarizing associations from our primary analyses together with published results.

RESULTS

In primary data analyses, parous women experienced at least 30% reduced risk of developing bladder cancer compared with nulliparous women (Shanghai: OR = 0.38, 95% CI: 0.13-1.10; CTS: RR = 0.69, 95% CI: 0.50-0.95) consistent with results of a meta-analysis of nine studies (summary RR = 0.73, 95% CI: 0.63-0.85). The CTS, which queried formulation of menopausal hormone therapy (HT), revealed a protective effect for use of combined estrogen and progestin compared with no HT (RR = 0.60, 95% CI: 0.37-0.98). Meta-analysis of three studies provided a similar effect estimate (summary RR = 0.65, 95% CI: 0.48-0.88).

CONCLUSIONS

A consistent pattern of reduced bladder cancer risk was found among parous women and those who used estrogen and progestin for HT.

IMPACT

These results suggest that more research is warranted to investigate hormonal and reproductive factors as possible contributors to bladder cancer risk.

Chromosome 4p16.3 variant modify bladder cancer risk in a Chinese population

A recent genome-wide association study identified a common variant (rs798766) on 4p16.3 that confers susceptibility to bladder cancer. The aim of this study was to assess whether rs798766 is associated with risk of bladder cancer in a Chinese population as well. We genotyped this variant using TaqMan technology in a case-control study of 815 histologically confirmed bladder cancer patients and 1141 controls. Normal bladder tissues adjacent to tumors were used to evaluate the functionality of rs798766 using quantitative real-time reverse transcription-polymerase chain reaction. We found that rs798766 CT/TT genotypes were associated with a significantly increased risk of bladder cancer (odds ratio = 1.36, 95% confidence interval = 1.10-1.67), compared with the CC genotype. Furthermore, rs798766 was significantly associated with FGFR3 messenger RNA expression. However, no significant interaction between rs798766 and tobacco smoking on bladder cancer risk was observed (P(multiplicative) = 0.785). Our results suggest that rs798766 on 4p16.3 may contribute to bladder cancer susceptibility in a Chinese population and explains an additional 3.65% of population attributable risk for bladder cancer.

Methods for the discovery of low-abundance biomarkers for urinary bladder cancer in biological fluids

For the study of bladder cancer and the identification of respective tumor markers, blood and, in particular, urine constitute suitable sources of biological material, while both harboring their specific challenges for analytics concerning low-abundance biomarkers. Dissolved proteins and nucleic acids as well as cells and cell-bound molecules can be the analytes. In urine, exfoliated bladder tumor cells have to be identified and in blood, circulating tumor cells have to be detected among huge amounts of other cells. For the detection of both low-abundance cells and molecules, their specific enrichment prior to analysis is advantageous or even necessary. Adapted methods for the analysis of proteomes and subproteomes by 2D-gel electrophoresis, multidimensional chromatography and antibody arrays are discussed. Analysis of nucleic acid-based markers exploits the high amplification power of PCR and modified PCR combined with previous (subtransciptomes) or subsequent (microarray) enrichment to sensitively and specifically detect markers. DNA mutations, DNA-methylation status and apoptotic DNA fragments, as well as levels of ribonucleic acids including microRNAs, can be analyzed by means of these methods. Finally, the challenge of identifying circulating tumor cells and assigning them to their original tissue is critically discussed.

Associations differ by sex for catechol-O-methyltransferase genotypes and bladder cancer risk in South Egypt

OBJECTIVES

To examine associations between urinary bladder cancer risk and polymorphisms of the gene encoding the catechol estrogen-metabolizing enzyme, catechol-O-methyltransferase (COMT), among Egyptian women and men.

MATERIALS AND METHODS

We used questionnaire and genotype data from a case-control study in Egypt. This analysis focused on South Egypt cases with confirmed urothelial (UC) or squamous cell (SCC) carcinoma of the bladder, and controls frequency-matched on sex, 5-year age-group, and residence governorate. Real-time PCR on blood specimen DNA was used to determine COMT genotypes encoding for Val/Val, Val/Met, and Met/Met, the enzyme forms associated with high, intermediate, or low activity, respectively.

RESULTS

The study sample, which included 255 women and 666 men, consisted of 394 cases with histologically confirmed UC (225) or SCC (n = 169), and 527 controls. The odds of having either type of bladder cancer were lower among men with genotypes encoding Val/Met or Met/Met than among those with the genotype encoding Val/Val, even after adjustment for other factors, such as smoking and schistosomiasis history [adjusted odds ratio (AOR): 0.64; 95% confidence interval (CI): 0.43, 0.96]; however, the association was statistically significant for SCC (AOR 0.57; 95% CI: 0.34, 0.96) but marginal for UC (AOR: 0.64; 95% CI: 0.39, 1.02). No significant associations were detected between bladder cancer risk and COMT genotypes among postmenopausal women.

CONCLUSIONS

These findings suggest that even after controlling for established risk factors, the involvement of COMT genotypes in bladder cancer risk differs among men compared with women in South Egypt.

Intervention of nicotine on MNU-induced bladder cancer in rats

This study examined the effect of nicotine on the expression of mutant p53 (mt-p53) in bladder cancer rats. The rat models of bladder cancer were established by infusing N-methyl-nitroso-urea (MNU, 10 mg/kg every 2 weeks for 8 weeks) into the bladder. Pathological examination on the bladder was conducted to confirm the establishment of the model. All the bladder cancer rats were randomly divided into an MNU group and 3 nicotine groups. In the nicotine groups, the rats were intragastrically administered nicotine at different concentrations (25, 15, 5 mg/kg respectively) 3 times per week for 8 weeks. The mt-p53 expression was detected by the immunohistochemical method. The results showed that rat bladder cancer models developed histopathological changes of bladder transitional cell carcinoma. The positive rate of mt-p53 expression in the 3 nicotine groups (25, 15, 5 mg/kg) was 75.00%, 58.33% and 41.67% by the 14th week, respectively, significantly higher than that in the MNU group (33.33%) (all P<0.05). The mt-p53 expression rate was positively correlated with the medication dose and time (P<0.05). It is concluded that nicotine may play an important role in the development of bladder cancer partially by increasing the expression of mt-p53.

Bladder cancer: a review of non-muscle invasive disease

BACKGROUND

Bladder cancer is one of the most common cancers affecting men and women and thus has a profound impact on health care. The majority of patients (75%) with newly diagnosed urothelial tumors have non-muscle invasive disease confined to the bladder mucosa or the lamina propria.

METHODS

The authors review the literature as well as recently published clinical guidelines regarding the bladder cancer risk and causative factors, diagnostic and pathologic evaluation, prognostic variables, and management strategies for patients with non-muscle invasive bladder cancer.

RESULTS

Recurrence and progression remain problematic for many patients and are dependent on multiple clinical and pathological features, the most important of which are tumor stage, grade, multifocality, size, recurrence patterns, and the association with carcinoma in situ. Accurate assessment of clinical stage and tumor grade is critical in determining management and surveillance strategies. Intravesical therapies positively influence tumor recurrence rates. Disease progression rates may be impacted in high-risk patients who receive both induction bacille Calmette-Guérin (BCG) and a maintenance BCG regimen. Cystectomy still plays a pivotal role in patients with high-risk tumors and in patients who fail more conservative attempts to eradicate non-muscle invasive disease.

CONCLUSIONS

Non-muscle invasive bladder cancers represent a broad group of tumors with varying biologic potential. Successful treatment depends on the careful integration of diagnostic and surveillance tests, macroablation through transurethral resection, accurate assessment of clinical stage, and the timely and appropriate delivery of intravesical chemotherapeutic and immunomodulatory agents.

Amount of tobacco consumption is associated with superficial bladder cancer progression

OBJECTIVE

To evaluate the association between smoking habits and outcome of patients with superficial bladder cancer.

METHODS

A retrospective study was performed evaluating 99 patients (67.0 ± 13.2 years, ranging from 31.4-93.4 years, 72.7% males and 27.3% females) treated at our institution with non muscle-invasive bladder cancer, between 1994 and 2000, with a mean follow-up of 49.3 months (range 4.0-177.9 months). Patients were divided according to smoking status, and the main measured outcome was progression to invasive disease. Additional cohort analysis was performed dividing patients according to previous tobacco exposure: smokers and non-smokers. Smokers were stratified into former smokers, early-quitters, late quitters and continued smokers.

RESULTS

Smoking habit was significantly more common in males (p = 0.03). Cancer also occurred at an earlier age among smokers (70.8 versus 64.8 years, p = 0.030). Tobacco consumption was present in 62.7% of the patients with bladder cancer. There was a significant higher progression rate to muscle-invasive disease in patients that had more than 60 pack-years of exposure (52.9 versus 26.2%, p = 0.037). These patients had a mean progression time of 59.3 months, whereas patients who had smoked less than 60 pack-years progressed after a mean time of 131.8 months.

CONCLUSIONS

A direct association between the amount of tobacco consumed and disease progression is observed in patients with bladder cancer, as suggested by the present study. Tobacco consumption has a direct association with progression of superficial bladder cancer to invasive disease and also shortens the period of time for muscle invasion. Larger and prospective studies are still necessary to bring further definitive conclusions about reproducibility of our data and to better understand how smoking cessation affects progression of superficial bladder cancer.

Combretastatin A-4 inhibits cell growth and metastasis in bladder cancer cells and retards tumour growth in a murine orthotopic bladder tumour model

BACKGROUND AND PURPOSE

Bladder cancer is a highly recurrent cancer after intravesical therapy, so new drugs are needed to treat this cancer. Hence, we investigated the anti-cancer activity of combretastatin A-4 (CA-4), an anti-tubulin agent, in human bladder cancer cells and in a murine orthotopic bladder tumour model.

EXPERIMENTAL APPROACH

Cytotoxicity of CA-4 was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, propidium iodide (PI) staining assay and clonogenic survival assay. In vivo microtubule assembly assay, cell cycle analyses, Western blot and cell migration assay were used to study the mechanism of CA-4. The effect of intravesical CA-4 therapy on the development of tumours was studied in the murine orthotopic bladder tumour model.

KEY RESULTS

CA-4 inhibited microtubule polymerization in vivo. Cytotoxic IC(50) values of CA-4 in human bladder cancer cells were below 4 nM. Analyses of cell-cycle distribution showed CA-4 obviously induced G(2)-M phase arrest with sub-G(1) formation. The analyses of apoptosis showed that CA-4 induced caspase-3 activation and decreased BubR1 and Bub3 in cancer cells. In addition to apoptosis, CA-4 was also found to induce the formation of multinucleated cells. CA-4 had a significantly reduced cell migration in vitro. Importantly, the in vivo study revealed that intravesical CA-4 therapy retarded the development of murine bladder tumours.

CONCLUSIONS AND IMPLICATIONS

These data demonstrate that CA-4 kills bladder cancer cells by inducing apoptosis and mitotic catastrophe. It inhibited cell migration in vitro and tumour growth in vivo. Hence, CA-4 intravesical therapy could provide another strategy for treating superficial bladder cancers.

Clinical characteristics of bladder urothelial tumors in male patients--the influences of benign prostatic hyperplasia/benign prostatic enlargement

OBJECTIVES

To investigate the clinical characteristics of bladder urothelial tumors in male patients.

PATIENTS AND METHODS

The clinical characteristics of 356 patients with newly diagnosed bladder urothelial tumors from July 2005 to January 2010 were analyzed. Characteristics of different age groups were compared. Furthermore, tumor characteristics were analyzed to define the relationship, if any, with benign prostatic hyperplasia/benign prostatic enlargement.

RESULTS

For bladder urothelial tumors, the percentage of carcinoma increased significantly with increasing age (P < 0.001), and differences were found among 3 age groups in the distribution of high grade carcinoma (P = 0.012). Especially in non-muscle-invasive carcinoma, the percentage of high grade carcinoma increased significantly with increasing age (P = 0.006), with significant differences between the ≤50 years group and the 51-69 years group and ≥70 years group (P = 0.031, P = 0.002). Interestingly, compared with non-benign prostatic hyperplasia/benign prostatic enlargement patients, benign prostatic hyperplasia/benign prostatic enlargement patients were more frequently diagnosed with poorly differentiated tumors, and logistic regression confirmed associations between benign prostatic hyperplasia/benign prostatic enlargement and unfavorable carcinoma, controlling for age (P = 0.009).

CONCLUSIONS

Age is an unfavorable influence on the clinical characteristics of bladder urothelial tumors in men, and it was observed that the percentage of unfavorable tumors increased with age. Interestingly, noticeable changes of tumor differentiation appeared at the age of 50 years, and it was indicated that the natural history of carcinoma appeared to differ according to benign prostatic hyperplasia/benign prostatic enlargement statuses. There was a tendency for the men, who were diagnosed with benign prostatic hyperplasia/benign prostatic enlargement, to present with unfavorable carcinoma.

Estrogen exposure and bladder cancer risk in Egyptian women

OBJECTIVE

To examine associations between reproductive history and urinary bladder cancer in Egyptian women.

METHODS

We used questionnaire data from an ongoing, multicenter case-control study in Egypt. Controls were matched on age and residence area. This analysis focused on female cases with confirmed urothelial (UC) and squamous cell (SCC) carcinoma of the bladder.

RESULTS

We recruited 779 women (540 controls, 239 cases; >98.0% nonsmokers). Younger age at menopause (<45 y) and older age at first pregnancy (>18 y) were factors significantly associated with increased risk of bladder cancer, even after adjusting for schistosomiasis history and other covariates in the multivariable logistic model; adjusted odds ratio and 95% confidence intervals were 1.98 (1.41, 2.77) and 6.26 (3.46, 11.34), respectively. On the other hand, multiple pregnancies or use of oral contraceptives were associated with decreased odds of having bladder cancer. Similar associations were observed with UC and SCC when analyzed separately; however, the magnitude of association with SCC was lower than with UC.

CONCLUSION

Our data suggest that early estrogen exposure, or the relative lack of it, plays a role in urinary bladder carcinoma development among Egyptian women.

Selenium and bladder cancer risk: a meta-analysis

BACKGROUND

Selenium is considered to be an antioxidant, and its high levels have been inversely associated with cancer risk of several sites. This meta-analysis examined the relationship between levels of selenium measured in serum and toenails, and the risk of bladder cancer.

METHODS

A meta-analysis using data from seven published epidemiologic studies (three case-control, three nested case-control, one case-cohort) published before March 2010 was done to examine the association between levels of selenium and bladder cancer. Fixed and random effects analyses were done to calculate meta-odds ratio (mOR) and 95% confidence intervals (CI). Heterogeneity among studies was measured by the I(2) statistic.

RESULTS

Overall, the risk of bladder cancer was inversely associated with elevated levels of selenium according to a random-effects model (mOR = 0.61; 95% CI, 0.42-0.87). The mORs were 0.95 (95% CI, 0.69-1.27) and 0.55 (95% CI, 0.32-0.95) among men and women, respectively. Sex, type of sample specimen, smoking status, and study design were found to be potential sources of heterogeneity.

CONCLUSIONS

A significant protective effect of selenium, observed mainly among women, may result from gender-specific differences in its accumulation and excretion. The heterogeneity found among studies was mainly linked to the different biological sample specimens used to measure the selenium concentrations and the small size of the studies. Although these results suggest a protective effect of selenium for bladder cancer risk, additional large studies are warranted to support these preliminary evidence.

IMPACT

The present results suggest a beneficial effect of high selenium intake for bladder cancer risk.

Down-regulation of type I interferon receptor sensitizes bladder cancer cells to vesicular stomatitis virus-induced cell death

The intrinsic oncolytic specificity of vesicular stomatitis virus (VSV) is currently being exploited to develop alternative therapeutic strategies for bladder cancer and other cancers. Previously we reported that oncolytic VSV is a potent agent for intravesical treatment of high risk bladder cancer. We observed that VSV preferentially targeted bladder cancer cells resistant to type I interferon (IFN) treatment. The goal of the current study was to further elucidate the nature of the molecular defect of IFN signaling by which bladder cancer cells become susceptible to VSV infection. Using a tissue microarray composed of human bladder cancer cores, we observed that expression of type I IFN receptor (IFNAR) was decreased relative to normal bladder tissue. Advanced bladder cancers had even lower expression of IFNAR. We found that bladder cancer cells susceptible to VSV-induced lysis had low expression of IFNAR as well. We hypothesized that down-regulation of IFNAR in bladder cancer cells may be a molecular mechanism responsible for resistance to type I IFN treatment and sensitivity to VSV oncolysis. SiRNA knockdown of IFNAR indeed facilitated replication of VSV in cells previously resistant to VSV treatment. Blocking IFNAR with a neutralizing antibody showed a similar effect. Hence down-regulation of IFNAR in bladder cancer may be one of the primary molecular mechanisms for clinical IFN resistance. However, this also facilitates VSV replication and oncolysis in high risk bladder cancers and provides a basis for selecting bladder cancer patients for IFN or oncolytic VSV therapy in future clinical trials.

A meta-analysis of alcohol intake and risk of bladder cancer

OBJECTIVE

Epidemiologic studies have reported conflicting results relating alcohol intake to bladder cancer risk. A meta-analysis of cohort and case-control studies was conducted to pool the risk estimates of the association between alcohol intake and bladder cancer.

METHODS

Eligible studies were retrieved via both computer searches and review of references. We analyzed abstracted data with random effects models to obtain the summary risk estimates. Dose-response meta-analysis was performed for studies reporting categorical risk estimates for a series of exposure levels.

RESULTS

Nineteen studies met the inclusion criteria of the meta-analysis. No association with bladder cancer was observed in either overall alcohol intake group (OR = 1.00, 95% CI 0.89-1.10) or subgroups stratified by sex, study design, geographical region, or smoking status. However, in the analysis by specific beverages, both beer (OR = 0.86, 95% CI 0.76-0.96) and wine (OR = 0.85, 95% CI 0.71-1.00) consumption exhibited a negative dose-response relationship with bladder cancer.

CONCLUSION

The overall current literature on alcohol consumption and the risk of bladder cancer suggested no association, while the consumption of beer and wine was associated with reduced risk of bladder cancer. Further efforts should be made to confirm these findings and clarify the underlying biological mechanisms.

Variation of keratin 7 expression and other phenotypic characteristics of independent isolates of cadmium transformed human urothelial cells (UROtsa)

This laboratory has shown that a human urothelial cell line (UROtsa) transformed by cadmium (Cd(2+)) produced subcutaneous tumor heterotransplants that resemble human transitional cell carcinoma (TCC). In the present study, additional Cd(2+) transformed cell lines were isolated to determine if independent exposures of the cell line to Cd(2+) would result in malignantly transformed cell lines possessing similar phenotypic properties. Seven independent isolates were isolated and assessed for their doubling times, morphology, ability to heterotransplant subcutaneously and in the peritoneal cavity of nude mice, and for the expression of keratin 7. The 7 cell lines all displayed an epithelial morphology with no evidence of squamous differentiation. Doubling times were variable among the isolates, being significantly reduced or similar to those of the parental cells. All 7 isolates were able to form subcutaneous tumor heterotransplants with a TCC morphology, and all heterotransplants displayed areas of squamous differentiation of the transitional cells. The degree of squamous differentiation varied among the isolates. In contrast to subcutaneous tumor formation, only 1 isolate of the Cd(2+) transformed cells (UTCd#1) was able to effectively colonize multiple sites within the peritoneal cavity. An analysis of keratin 7 expression showed no correlation with squamous differentiation for the subcutaneous heterotransplants generated from the 7 cell lines. Keratin 7 was expressed in 6 of the 7 cell lines and their subcutaneous tumor heterotransplants. Keratin 7 was not expressed in the cell line that was able to form tumors within the peritoneal cavity. These results show that individual isolates of Cd(2+) transformed cells have both similarities and differences in their phenotype.

Dairy intake and the risk of bladder cancer in the Netherlands Cohort Study on Diet and Cancer

The authors examined the association between the intake of different dairy products and the risk of bladder cancer in 120,852 men and women aged 55-69 years participating in the Netherlands Cohort Study on Diet and Cancer. Dairy product intake was assessed in 1986 by using a 150-item food frequency questionnaire. The cohort was followed for 16.3 years, and 1,549 incident cases of bladder cancer were analyzed. Cox proportional hazards analysis was applied with a case-cohort approach by using the follow-up data of a random subcohort (n = 5,000). Multivariate hazard ratio estimates comparing the highest with the lowest quintile of total dairy intake were 1.01 (95% confidence interval (CI): 0.81, 1.27; P(trend) = 0.68). A statistically significant association for fermented milk products was found only for the second quintile (median, 12 g/day) (hazard ratio = 0.71, 95% CI: 0.56, 0.91). Compared with nonconsumers, women with 25-75 g/day of butter consumption had a hazard ratio of 1.61 (95% CI: 1.03, 2.50; P(trend) < 0.01). No association was found with cheese, calcium, lactose, or nonfermented dairy intake. These results provide weak evidence that bladder cancer risk is inversely associated with low intake of fermented dairy products and suggest a positive association with butter intake in women.