Epidemiology and prevention of bladder cancer

Addressing disparities in European cancer outcomes: a qualitative study Protocol of the BEACON project

Introduction

Health disparities represent a crucial factor in cancer survival rates, awareness, quality of life, and mental health of people receiving a cancer diagnosis and their families. Income, education, geographic location, and ethnicity are some of the most important underlying reasons for health disparities in cancer across Europe. Costs of healthcare, access to information, psycho-oncological support options, integration of cancer research and innovative care, and multidisciplinary cancer teams are the main target areas when it comes to addressing disparities in the cancer context. As part of the Beacon Project (BEACON), we developed a protocol for a qualitative study to explore and identify any relevant reasons for cancer inequalities and disparities in Europe.

Methods

Our four stakeholders namely, cancer patients, healthcare providers, researchers, and policymakers will be recruited online, facilitated by collaborative efforts with cancer organizations from various European countries, including but not limited to Italy, Croatia, Estonia, and Slovenia. Qualitative online focus group discussions for each stakeholder will be conducted and transcribed. Subsequently, thematic analysis will be used to identify reasons and aspects that may contribute to the existing disparities in cancer outcomes at various levels of engagement and from different stakeholders' perspectives. Results from focus groups will inform a subsequent Delphi study and a SWOT analysis methodology.

Discussion

Although advances in medical research, cancer screening and treatment options are constantly progressing, disparities in access to and awareness of healthcare in cancer patients are even more noticeable. Thus, mapping the capacity and capability of cancer centres in the European Union, creating decision support tools that will assist the four stakeholders' information needs and improving the quality of European cancer centres will be the main objectives of the BEACON project. The current protocol will outline the methodological and practical procedures to conduct online focus group discussions with different stakeholders.

Silica and asbestos exposure at work and the risk of bladder cancer in Canadian men: a population-based case-control study

Background

Silica and asbestos are recognized lung carcinogens. However, their role in carcinogenesis at other organs is less clear. Clearance of inhaled silica particles and asbestos fibers from the lungs may lead to translocation to sites such as the bladder where they may initiate carcinogenesis. We used data from a Canadian population-based case-control study to evaluate the associations between these workplace exposures and bladder cancer.

Methods

Data from a population-based case-control study were used to characterize associations between workplace exposure to silica and asbestos and bladder cancer among men. Bladder cancer cases (N = 658) and age-frequency matched controls (N = 1360) were recruited within the National Enhanced Cancer Surveillance System from eight Canadian provinces (1994–97). Exposure concentration, frequency and reliability for silica and asbestos were assigned to each job, based on lifetime occupational histories, using a combination of job-exposure profiles and expert review. Exposure was modeled as ever/never, highest attained concentration, duration (years), highest attained frequency (% worktime) and cumulative exposure. Odds ratios (OR) and their 95% confidence intervals (CI) were estimated using adjusted logistic regression.

Results

A modest (approximately 20%) increase in bladder cancer risk was found for ever having been exposed to silica, highest attained concentration and frequency of exposure but this increase was not statistically significant. Relative to unexposed, the odds of bladder cancer were 1.41 (95%CI: 1.01–1.98) times higher among men exposed to silica at work for ≥27 years. For asbestos, relative to unexposed, an increased risk of bladder cancer was observed for those first exposed ≥20 years ago (OR:2.04, 95%CI:1.25–3.34), those with a frequency of exposure of 5–30% of worktime (OR:1.45, 95%CI:1.06–1.98), and for those with < 10 years of exposure at low concentrations (OR:1.75, 95%CI:1.10–2.77) and the lower tertile of cumulative exposure (OR:1.69, 95%CI:1.07–2.65). However, no clear exposure-response relationships emerged.

Conclusions

Our results indicate a slight increase in risk of bladder cancer with exposure to silica and asbestos, suggesting that the effects of these agents are broader than currently recognized. The findings from this study inform evidence-based action to enhance cancer prevention efforts, particularly for workers in industries with regular exposure.

Androgen Receptor: Evaluation and Correlation with Recurrence and Clinicopathological Parameters in Papillary Urothelial Carcinomas of the Urinary Bladder

Papillary urothelial carcinoma (PUC) is the most common malignant tumor of the urinary bladder. Urothelial tumors are notorious for frequent recurrences and follow a chronic relapsing course in most of the patients. In Pakistan, the incidence of PUC is showing a rising trend. Various immunohistochemical (IHC) markers including androgens have been studied as prognostic and predictive markers in PUC with conflicting results. Androgen is a steroid-based sex hormone and plays an important role in different body organs such as urinary bladder, prostate, muscles, and brain. We aimed to investigate the role of the IHC expression of androgen receptor (AR) as a predictor of recurrence in papillary urothelial carcinoma patients. Eighty-four patients were included in the study. Tissues from the biopsy specimens of these cases were stained with antibodies against AR; 17% of the cases demonstrated a positive AR IHC expression. The expression was slightly more common in low-grade carcinoma. The AR expression was not significantly associated with clinicopathological features. Recurrence was observed in 49% of the cases, and it was significantly more common in AR-negative cases (p-value: 0.025). Eighteen out of 19 patients who died of disease were AR- negative, but no statistical significance was observed. We conclude that the IHC expression of AR can be used as a predictive marker for PUC as it correlates with the recurrence rate.

TP53 codon 72 polymorphism is associated with FGFR3 and RAS mutation in non-muscle-invasive bladder cancer

Objective

TP53, a well-known tumor-suppressor gene in bladder carcinogenesis, has a functional single-nucleotide polymorphism on codon 72. The aim of this study was to elucidate the association between TP53 codon 72 polymorphism and somatic mutations in bladder cancer.

Material and methods

Germline TP53 codon 72 polymorphism and somatic mutations of 50 cancer-associated genes were analyzed in 103 bladder cancer patients (59 non-muscle-invasive and 44 muscle-invasive), using Taqman genotyping assay and target sequencing, respectively. The expression of FGF-FGFR signaling pathway genes was analyzed by RNA sequencing of frozen tissue.

Results

The allele frequency of TP53 codon 72 in our cohort was 37, 42, and 21% for Arg/Arg, Arg/Pro, and Pro/Pro, respectively. Interestingly, the prevalence of FGFR3 mutation was higher in patients with the Arg allele, whereas that of the RAS mutation was higher in patients without the Arg allele. The same association was seen in non-muscle-invasive bladder cancer (NMIBC) patients and no differences were observed in muscle-invasive bladder cancer patients. In NMIBC, FGFR1 expression was higher in patients without the Arg allele and FGFR3 expression was higher in patients with the Arg allele.

Conclusion

The germline TP53 codon 72 polymorphism was associated with mutations of FGFR3 or RAS and expression of FGFR1 and FGFR3 in NMIBC. These findings provide new insight into the molecular mechanisms underlying the influence of the genetic background on carcinogenesis in bladder cancer.

Cancer Mortality in Italy, 1998

This short report provides data and statistics of cancer mortality in Italy in 1998, updating previous work on the issue. The material and methods of this report are similar to those previously described1,2. Briefly, cancer death certification numbers by cause and estimates of the resident population in 1998, stratified by sex and quinquennia of age, were abstracted from data provided by the Istituto Nazionale di Statistica (ISTAT)3. All cancers or groups of cancers, classified according to the standard International Classification of Diseases (ICD), Ninth Revision4, were grouped in 31 categories, besides total cancer mortality and other and unspecified sites. We grouped together all intestinal sites, melanomas and non-melanomatous skin neoplasms, all uterine neoplasms (cervix and corpus), all neoplasms of the brain and nerves (benign and malignant), all leukemias, and all non-Hodgkin's lymphomas.

Eight tables were produced, including the following statistics: 1) number of deaths, crude and age-standardized death certification rates, and percentages of all cancer deaths for population at all ages and truncated 35-64 years (Table 1 for males and Table 2 for females). Two different standards were used: i) the 1971 Italian census population, corrected for census undercount and subdivided into 16 quinquennia of age from 0-4 to 75-79, plus 80 and over, and ii) the world standard population, for purposes of comparison with other countries; 2) age-specific death certification rates for each sex and quinquennium of age from 0-4 to 75-79, plus 80 and over (Table 3 for males and Table 4 for females); 3) total number of registered deaths for each cancer or group of cancers, sex and age group (Table 5 for males and Table 6 for females); 4) percentage of all cancer deaths for each sex and age group (Table 7 for males and Table 8 for females).

A few comments are included, mainly in order to assist reading and interpretation of data for major cancer sites, and to recall underlying long-term tendencies. Any inference should in any case be based on age-standardized rates, and, essentially, on detailed inspection of age-specific rates.

Cost of illness of urothelial bladder cancer in Italy

Background

Urothelial bladder cancer (UBC) is the ninth most common cancer worldwide. In Italy, the prevalence of the disease is approximately 10%, making it the fourth most prevalent cancer in the country. The increase in prevalence requires continuous surveillance and care, resulting in a significant burden on Italian National Health Service, making any improvement to the strategy for diagnosing and treating this disease important to the medical and scientific community. The aim of this study was to evaluate the UBC cost of illness in the Italian context, collecting the total costs of the disease.

Methods

An economic analysis was carried out in the context of the National Health Service, using data collected from six centers, in order to evaluate direct costs in terms of outpatient, inpatient, and emergency care; pharmaceuticals and follow-up procedures; and indirect costs in terms of productivity losses. Data were collected through aggregated form reports, focusing on patients with an existing diagnosis of UBC who were treated in the last year. The Italian Association of Medical Oncology (AIOM) guidelines were used to identify diagnostic and therapeutic procedures. Statistical analysis was conducted to explore variations among centers.

Results

The weighted mean total annual cost per patient was € 3,591, where the cost for superficial disease was € 3,252 and that for metastatic disease was € 606. The analysis confirmed a proportional relation between disease severity and disability grade. The UBC cost of illness, considering prevalence and incidence data coming from the 2016 AIOM/Italian Association of Cancer Registries report, was € 1,187,036,344. Indirect costs accounted to 44%, represented by estimated productivity losses.

Conclusion

Our analysis represents the first economic study of UBC in the Italian context, as well as the first real-life evidence of the current therapeutic algorithm. This study opens the possibility for further analysis on the indirect cost components that represent a great burden for the society, especially for those in the severest stages of the disease with high disability grades.

Characterization of Gas-Phase Organics Using Proton Transfer Reaction Time-of-Flight Mass Spectrometry: Aircraft Turbine Engines

Nonmethane organic gas emissions (NMOGs) from in-service aircraft turbine engines were investigated using a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) at an engine test facility at Zurich Airport, Switzerland. Experiments consisted of 60 exhaust samples for seven engine types (used in commercial aviation) from two manufacturers at thrust levels ranging from idle to takeoff. Emission indices (EIs) for more than 200 NMOGs were quantified, and the functional group fractions (including acids, carbonyls, aromatics, and aliphatics) were calculated to characterize the exhaust chemical composition at different engine operation modes. Total NMOG emissions were highest at idling with an average EI of 7.8 g/kg fuel and were a factor of ∼40 lower at takeoff thrust. The relative contribution of pure hydrocarbons (particularly aromatics and aliphatics) of the engine exhaust decreased with increasing thrust while the fraction of oxidized compounds, for example, acids and carbonyls increased. Exhaust chemical composition at idle was also affected by engine technology. Older engines emitted a higher fraction of nonoxidized NMOGs compared to newer ones. Idling conditions dominated ground level organic gas emissions. Based on the EI determined here, we estimate that reducing idle emissions could substantially improve air quality near airports.

Commonest Cancers in Pakistan - Findings and Histopathological Perspective from a Premier Surgical Pathology Center in Pakistan

CONTEXT

There are no recent authoritative data about incidence and prevalence of various types of cancers in Pakistan.

AIM

To determine the frequency of malignant tumors seen in our practice and provide a foundation for building a comprehensive cancer care strategy.

MATERIALS AND METHODS

10,000 successive cases of solid malignant tumors reported in 2014 were included. All cases had formalin fixed, paraffin embedded specimens available and diagnosis was based on histological examination of H and E stained slides plus ancillary studies at the Section of Histopathology, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, Karachi. The latest WHO classifications were used along with the latest CAP protocols for reporting and the most updated TNM staging.

RESULTS

There were 9,492 (94.9%) primary tumors while 508 (5.1%) were metastatic. Some 5,153 (51.5%) were diagnosed in females and 4,847 (48.5%) in males. The commonest malignant tumors in females were breast (32%), esophagus (7%), lymphomas (6.8%), oral cavity (6.7%) and ovary (4.8%), while in males they were oral cavity (13.9%), lymphomas (12.8%), colorectum (7.9%), stomach (6.9%) and esophagus (6.6%). Malignant tumors were most common in the 5th, 6th and 7th decades. About 8% were seen under 20 years of age.

CONCLUSIONS

Oral cavity and gastrointestinal cancers continue to be extremely common in both genders. Breast and esophageal cancers are prevalent in females. Lung and prostate cancer are less common than in the west. Ovarian cancer was very common but cervix cancer was less so.

Bladder cancer and occupational exposure to diesel and gasoline engine emissions among Canadian men

The International Agency for Research on Cancer has classified diesel exhaust as a carcinogen based on lung cancer evidence; however, few studies have investigated the effect of engine emissions on bladder cancer. The purpose of this study was to investigate the association between occupational exposure to diesel and gasoline emissions and bladder cancer in men using data from the Canadian National Enhanced Cancer Surveillance System; a population‐based case–control study. This analysis included 658 bladder cancer cases and 1360 controls with information on lifetime occupational histories and a large number of possible cancer risk factors. A job‐exposure matrix for engine emissions was supplemented by expert review to assign values for each job across three dimensions of exposure: concentration, frequency, and reliability. Odds ratios (OR) and their corresponding 95% confidence intervals were estimated using logistic regression. Relative to unexposed, men ever exposed to high concentrations of diesel emissions were at an increased risk of bladder cancer (OR = 1.64, 0.87–3.08), but this result was not significant, and those with >10 years of exposure to diesel emissions at high concentrations had a greater than twofold increase in risk (OR = 2.45, 1.04–5.74). Increased risk of bladder cancer was also observed with >30% of work time exposed to gasoline engine emissions (OR = 1.59, 1.04–2.43) relative to the unexposed, but only among men that had never been exposed to diesel emissions. Taken together, our findings support the hypothesis that exposure to high concentrations of diesel engine emissions may increase the risk of bladder cancer.

Pesticides, gene polymorphisms, and bladder cancer among Egyptian agricultural workers

This study examined the associations between pesticide exposure, genetic polymorphisms for

NAD(P)H

quinone oxidoreductase I (NQO1) and superoxide dismutase 2 (SOD2), and urinary bladder cancer risk among male agricultural workers in Egypt. Logistic regression was used to analyze data from a multicenter case-control study and estimate adjusted odds ratio (OR) and 95% confidence interval (CI). Exposure to pesticides was associated with increased bladder cancer risk (odds ratio (95% confidence interval): 1.68 (1.23-2.29)) in a dose-dependent manner. The association was slightly stronger for urothelial (1.79 (1.25-2.56)) than for squamous cell (1.55 (1.03-2.31)), and among participants with combined genotypes for low NQO1 and high SOD2 (2.14 (1.19-3.85)) activities as compared with those with high NQO1 and low SOD2 genotypes (1.53 (0.73-3.25)). In conclusion, among male agricultural workers in Egypt, pesticide exposure is associated with bladder cancer risk and possibly modulated by genetic polymorphism.

Urinary bladder cancer risk factors: a Lebanese case- control study

BACKGROUND

Bladder cancer is the second most incident malignancy among Lebanese men. The purpose of this study was to investigate potential risk factors associated with this observed high incidence.

METHODS

A case-control study (54 cases and 105 hospital-based controls) was conducted in two major hospitals in Beirut. Cases were randomly selected from patients diagnosed in the period of 2002-2008. Controls were conveniently selected from the same settings. Data were collected using interview questionnaire and blood analysis. Exposure data were collected using a structured face-to-face interview questionnaire. Blood samples were collected to determine N-acetyltransferase1 (NAT1) genotype by PCR-RFLP. Analyses revolved around univariate, bivariate and multivariate logistic regression, along with checks for effect modification.

RESULTS

The odds of having bladder cancer among smokers was 1.02 times significantly higher in cases vs. controls. The odds of exposure to occupational diesel or fuel combustion fumes were 4.1 times significantly higher in cases vs controls. The odds of prostate-related morbidity were 5.6 times significantly higher in cases vs controls. Cases and controls showed different clustering patterns of NAT1 alleles. No significant differences between cases and controls were found for consumption of alcohol, coffee, tea, or artificial sweeteners.

CONCLUSIONS

This is the first case-control study investigating bladder cancer risk factors in the Lebanese context. Results confirmed established risk factors in the literature, particularly smoking and occupational exposure to diesel. The herein observed associations should be used to develop appropriate prevention policies and intervention strategies, in order to control this alarming disease in Lebanon.

Prognostic value of sex-hormone receptor expression in non-muscle-invasive bladder cancer

PURPOSE

We investigated sex-hormone receptor expression as predicting factor of recurrence and progression in patients with non-muscle invasive bladder cancer.

MATERIALS AND METHODS

We retrospectively evaluated tumor specimens from patients treated for transitional cell carcinoma of the bladder at our institution between January 2006 and January 2011. Performing immunohistochemistry using a monoclonal androgen receptor antibody and monoclonal estrogen receptor-beta antibody on paraffin-embedded tissue sections, we assessed the relationship of immunohistochemistry results and prognostic factors such as recurrence and progression.

RESULTS

A total of 169 patients with bladder cancer were evaluated in this study. Sixty-threepatients had expressed androgen receptors and 52 patients had estrogen receptor beta. On univariable analysis, androgen receptor expression was significant lower in recurrence rates (p=0.001), and estrogen receptor beta expression was significant higher in progression rates (p=0.004). On multivariable analysis, significant association was found between androgen receptor expression and lower recurrence rates (hazard ratio=0.500; 95% confidence interval, 0.294 to 0.852; p=0.011), but estrogen receptor beta expression was not significantly associated with progression rates.

CONCLUSION

We concluded that the possibility of recurrence was low when the androgen receptor was expressed in the bladder cancer specimen and it could be the predicting factor of the stage, number of tumors, carcinoma in situ lesion and recurrence.

Cancer Incidence and Mortality in the Industrial City of Sumgayit, Azerbaijan

This study, the first environmental cancer study in Azerbaijan, addressed concerns that residents of the industrial city of Sumgayit have an increased cancer burden as a consequence of intense occupational and environmental pollution from industry. Vital statistics data were used to calculate annual crude cancer incidence and mortality rates for selected cancers and regions in Azerbaijan for the years 1980-2000. Poisson regression analysis of age- and sex-specific data from 1995-2000 demonstrates an increased risk for selected cancers in Sumgayit relative to the rest of the country, as measured by adjusted rate ratios [aRR (95% CI))]: larynx 1.39 (1.04, 1.85), lung 1.67 (1.44, 1.92), bladder 2.49 (1.93, 3.22), and all sites 1.51 (1.43, 1.58). Sumgayit appears to suffer from an increased cancer burden; poor data quality and suspected underreporting, however, prevent accurate estimates of incidence or mortality rates. Construction of a modern cancer registry would be prerequisite to more detailed examinations of cancer rates in the country.

Epidemiologic and socioeconomic status of bladder cancer in Mazandaran Province, northern Iran

BACKGROUND

Bladder cancer is one the most common malignancies of the genitourinary tract. The present study aimed to assess the epidemiology, of bladder cancer in Mazandaran, a large province in northern Iran as high-incidence cancer area, during a 2-year period.

METHODS

The data for this study were obtained from the population-based cancer registry of the Vice-Chancellory for Health Affairs of Mazandaran University of Medical Sciences and Mazandaran hospitals between March 1, 2010 and March 1, 2011. Demographic data, including sex, age, residency and symptoms were investigated through careful review of medical records. Using a questionnaire protocol, several variables were assessed for these cases such as smoking, history of opium, vegetable consumption habits, and history of other cancers.

RESULTS

A total of 112 cases were analyzed, 98 (87.5%) in men and 14 (12.5%) in women (mean age of 68.0 ± 14.6 years). Urban and rural residence were 60.7% and 39.3%. Tobacco and opium use were found in 45.5% and 21.4% of patients, respectively. Approximately 60% consumed vegetables an average of fewer than one time per day. Hematuria was the first symptom in these cases which were mainly diagnosed as having bladder cancer by ultrasonography.

CONCLUSION

The results showed that bladder cancer tends to be found in the elderly and the male to female ratio is high. Macroscopic hematuria is a very important symptom for indicating probably urothelial tumor that should be followed up patients with transabdominal ultrasonography as a routine modality.

[Epidemiology of disease conditions in Italy. Has anything changed? Environment, professional exposure, and lifestyle. Is time for screening?]

Risk factors analysis in bladder cancer should consider not only the clinical and pathological features of the tumor but also environmental and lifestyle factors. They may play, in fact, a relevant role not only in the pathogenesis but also in the biological behavior of the tumor. The association between cigarette smoking and bladder cancer has been consistently confirmed in several case-control and cohort studies. The risk of bladder cancer seems to increase with duration and intensity of smoking. Another environmental risk factor, although not definitively proved, is water supply. Chlorination or water pollution by pesticides and other chemical factors is considered a relevant risk factor. Familiarity and genetic predisposition, diet and individual risk factors should be taken into account.

Sex differences in the physiology and pharmacology of the lower urinary tract

Sexual dimorphism is not only noticed in the prevalence of many diseases, but also in multiple physiological functions in the body. This review has summarized findings from published literature on the sex differences of the pathophysiology and pharmacology of the lower urinary tract (LUT) of humans and animals. Sex differences have been found in several key areas of the LUT, such as overactive bladder, expression and function of neurotransmitter receptors in the bladder and urethra, and micturition patterns in humans and animals. It is anticipated that this review will not only evoke renewed interest for further research on the mechanism of sex differences in the pathophysiology of the LUT (especially for overactive bladder), but might also open up the possibilities for gender-based drug development by pharmaceutical industries in order to find separate cures for men and women with diseases of the LUT.

Germline prognostic markers for urinary bladder cancer: obstacles and opportunities

Urinary bladder cancer is a heterogeneous disease with diverse genetic and environmental risk factors that can influence disease risk or clinical course for recurrence, progression, and survival. Therefore, identification of these factors is paramount for disease prevention and optimal clinical management of bladder cancer patients. Of particular interest is the need to identify molecular biomarkers that can give accurate assessment of tumor biological potential and to predict treatment response. Recent advances in molecular biology, cytogenetic, and genomic research have spurred discovery efforts for novel genetic, epigenetic, and proteomic biomarkers that are prognostic for cancer. This review focuses on some of the important germ line polymorphisms found to be correlated with clinical outcomes in bladder cancer. So far, most of the identified candidate loci were based on prior knowledge of pathogenesis and had not been validated for clinical applications. The future challenges are to analyze the wealth of information from whole-genome studies, to understand the underlying biological mechanisms of these associations, the network of gene-gene and gene-environment interactions, and to apply these markers for the identification of high-risk population for targeted, personalized therapy.

Mortality and morbidity study of petrochemical employees in a polluted site

BACKGROUND

The area of Gela was included among the 57 Italian polluted sites of national interest for environmental remediation because of its widespread contamination from a petrochemical complex. The present study investigates mortality and morbidity of the cohort of Gela petrochemical workers with the aim of disentangling occupational from residential risk.

METHODS

Mortality was assessed for 5,627 men hired from 1960, year of the plant start-up, to 1993; it was followed up for vital status in the period 1960-2002. Morbidity was analysed for 5,431 workers neither dead nor lost to follow-up from 1960 to 2001 and was based on Hospital Discharge Records in the period 2001-2006. The work experience was classified in terms of job categories such as blue collars, white collars, and both--workers who shifted from blue to white collar (95%) or vice versa. An ad hoc mobility model was applied to define qualitative categories of residence in Gela, as residents and commuters. Standardized Mortality Ratios (SMRs) and Mortality Rate Ratios (MRRs) were computed, the latter by using a Poisson regression model. Morbidity was analyzed in terms of Hospital Discharge Odds Ratios (HDORs) through a logistic regression model. While performing the internal comparisons, white collars was the reference category for the job analysis, and commuters was the reference category for the residential analysis.

RESULTS

In the light of epidemiological evidence about health risk from petrochemical industries in both occupational and environmental settings, and/or on the basis of information about occupational and residential contamination and health risk in the area of Gela, noteworthy results are shown for lung cancer [MRR: 2.11 (CI 90%; 0.96-4.63) in blue collars; 1.71 (1.09-2.69) in residents], respiratory diseases [HDOR: 2.0 (1.0-3.0) in blue collars; 1.4 (0.96-2.06) in residents] and genitourinary diseases [HDOR: 1.34 (1.06-1.68) in blue collars; 1.23 (1.04-1.45) in residents].

CONCLUSIONS

The results support a role of the exposures in the occupational and residential settings, the latter due to the local ascertained contamination, in affecting the workers' health. These results underline the urgent need of water, soil, air and food-chain monitoring programs, to discover active sources of exposure and consequently define public health interventions.

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.

Cancer burden in Africa and opportunities for prevention

Cancer is an emerging public health problem in Africa. About 715,000 new cancer cases and 542,000 cancer deaths occurred in 2008 on the continent, with these numbers expected to double in the next 20 years simply because of the aging and growth of the population. Furthermore, cancers such as lung, female breast, and prostate cancers are diagnosed at much higher frequencies than in the past because of changes in lifestyle factors and detection practices associated with urbanization and economic development. Breast cancer in women and prostate cancer in men have now become the most commonly diagnosed cancers in many Sub-Saharan African countries, replacing cervical and liver cancers. In most African countries, cancer control programs and the provision of early detection and treatment services are limited despite this increasing burden. This paper reviews the current patterns of cancer in Africa and the opportunities for reducing the burden through the application of resource level interventions, including implementation of vaccinations for liver and cervical cancers, tobacco control policies for smoking-related cancers, and low-tech early detection methods for cervical cancer, as well as pain relief at the palliative stage of cancer.

Identification of an unintended consequence of Nrf2-directed cytoprotection against a key tobacco carcinogen plus a counteracting chemopreventive intervention

NF-E2-related factor 2 (Nrf2) is a major cytoprotective gene and is a key chemopreventive target against cancer and other diseases. Here we show that Nrf2 faces a dilemma in defense against 4-aminobiphenyl (ABP), a major human bladder carcinogen from tobacco smoke and other environmental sources. Although Nrf2 protected mouse liver against ABP (which is metabolically activated in liver), the bladder level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), the predominant ABP-DNA adduct formed in bladder cells and tissues, was markedly higher in Nrf2(+/+) mice than in Nrf2(-/-) mice after ABP exposure. Notably, Nrf2 protected bladder cells against ABP in vitro. Mechanistic investigations showed that the dichotomous effects of Nrf2 could be explained at least partly by upregulation of UDP-glucuronosyltransferase (UGT). Nrf2 promoted conjugation of ABP with glucuronic acid in the liver, increasing urinary excretion of the conjugate. Although glucuronidation of ABP and its metabolites is a detoxification process, these conjugates, which are excreted in urine, are known to be unstable in acidic urine, leading to delivery of the parent compounds to bladder. Hence, although higher liver UGT activity may protect the liver against ABP, it increases bladder exposure to ABP. These findings raise concerns of potential bladder toxicity when Nrf2-activating chemopreventive agents are used in humans exposed to ABP, especially in smokers. We further show that 5,6-dihydrocyclopenta[c][1,2]-dithiole-3(4H)-thione (CPDT) significantly inhibits dG-C8-ABP formation in bladder cells and tissues but does not seem to significantly modulate ABP-catalyzing UGT in liver. Thus, CPDT exemplifies a counteracting solution to the dilemma posed by Nrf2.

Spatio-temporal patterns of bladder cancer incidence in Utah (1973-2004) and their association with the presence of toxic release inventory sites

Background

The authors analyse the spatio-temporal variations of the incidence of bladder cancer between 1973 and 2004 in Utah at the census tract level (496 areas) to highlight areas of high and low relative risks that remained so throughout the 32 year period. Using these identified areas, a novel strategy is used to carry out a geographical case-control study of association between the risk of bladder cancer and presence of Toxic Release Inventory sites, where areas with stable high RRs are 'case areas' and all remaining areas with stable non increased risks are 'control areas'.

Results

The time trend of bladder cancer risk fluctuated over the study period: A steady decrease was observed, followed by an abrupt increase from 1992 to 2004. Using a Bayesian space-time model, 93 census tracts were classified as having an excess relative risk and 81 a lower relative risk, sustained over the 32 years. We showed that these high relative risk areas for bladder cancer were associated with the presence of Toxic Release Inventory sites, after adjusting for the proportion of Latter-Day Saint Church members as an area level proxy for smoking habits.

Conclusions

Our study has demonstrated that the modeling of data in time and space has additional benefits over a purely spatial analysis. In addition to highlighting the areas with high and low relative risks, this model also allows the simultaneous study of persistency of spatial patterns over time and detection of 'unusual' time trends that may warrant further investigation.

Protective effects of plasma alpha-tocopherols on the risk of inorganic arsenic-related urothelial carcinoma

Arsenic plays an important role in producing oxidative stress in cultured cells. To investigate the interaction between high oxidative stress and low arsenic methylation capacity on arsenic carcinogenesis, a case-control study was conducted to evaluate the relationship among the indices of oxidative stress, such as urinary 8-hydroxydeoxyquanine (8-OHdG), as well as plasma micronutrients and urinary arsenic profiles on urothelial carcinoma (UC) risk. Urinary 8-OHdG was measured using high-sensitivity enzyme-linked immunosorbent assay kits. The urinary arsenic species were analyzed using high-performance liquid chromatography and hydride generator-atomic absorption spectrometry. Plasma micronutrient levels were analyzed using reversed-phase high-performance liquid chromatography. The present study showed a significant protective effect of plasma alpha-tocopherol on UC risk. Plasma alpha-tocopherol levels were significantly inversely related to urinary total arsenic concentrations and inorganic arsenic percentage (InAs%), and significantly positively related to dimethylarsinic acid percentage (DMA%). There were no correlations between plasma micronutrients and urinary 8-OHdG. Study participants with lower alpha-tocopherol and higher urinary total arsenic, higher InAs%, higher MMA%, and lower DMA% had a higher UC risk than those with higher alpha-tocopherol and lower urinary total arsenic, lower InAs%, lower MMA%, and higher DMA%. These results suggest that plasma alpha-tocopherol might modify the risk of inorganic arsenic-related UC.

Gene polymorphisms of glutathione S-transferase omega 1 and 2, urinary arsenic methylation profile and urothelial carcinoma

Genetic polymorphisms in arsenic-metabolizing enzymes may be involved in the biotransformation of inorganic arsenic and may increase the risk of developing urothelial carcinoma (UC). The present study evaluated the roles of glutathione S-transferase omega 1 (GSTO1) and GSTO2 polymorphisms in UC carcinogenesis. A hospital-based case-control study was conducted. Questionnaire information and biological specimens were collected from 149 UC cases and 251 healthy controls in a non-obvious inorganic arsenic exposure area in Taipei, Taiwan. The urinary arsenic profile was determined using high-performance liquid chromatography and hydride generator-atomic absorption spectrometry. Genotyping for GSTO1 Ala140Asp and GSTO2 Asn142Asp was conducted using polymerase chain reaction-restriction fragment length polymerase. GSTO1 Glu208Lys genotyping was performed using high-throughput matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. A significant positive association was found between total arsenic, inorganic arsenic percentage and monomethylarsonic acid percentage and UC, while dimethylarsinic acid percentage was significantly inversely associated with UC. The minor allele frequency of GSTO1 Ala140Asp, GSTO1 Glu208Lys and GSTO2 Asn142Asp was 18%, 1% and 26%, respectively. A significantly higher MMA% was found in people who carried the wild type of GSTO1 140 Ala/Ala compared to those who carried the GSTO1 140 Ala/Asp and Asp/Asp genotype (p=0.02). The homogenous variant genotype of GSTO2 142 Asp/Asp was inversely associated with UC risk (OR=0.17; 95% CI, 0.03 - 0.88; p=0.03). Large-scale studies will be required to verify the association between the single nucleotide polymorphisms of arsenic-metabolism-related enzymes and UC risk.

Sulforaphane inhibits 4-aminobiphenyl-induced DNA damage in bladder cells and tissues

Sulforaphane (SF) is a well-known chemopreventive phytochemical and occurs in broccoli and to a lesser extent in other cruciferous vegetables, whereas 4-aminobiphenyl (ABP) is a major human bladder carcinogen and is present at significant levels in tobacco smoke. Here, we show that SF inhibits ABP-induced DNA damage in both human bladder cells in vitro and mouse bladder tissue in vivo, using dG-C8-ABP as a biomarker, which is the predominant ABP-DNA adduct formed in human bladder cells and tissues. SF activates NF-E2 related factor-2 (Nrf2), which is a well-recognized chemopreventive target and activates the Nrf2-regulated cytoprotective signaling pathway. Comparison between wild-type mice and mice without Nrf2 shows that Nrf2 activation is required by SF for inhibition of ABP-induced DNA damage. Moreover, Nrf2 activation by SF in the bladder occurs primarily in the epithelium, which is the principal site of bladder cancer development. These data, together with our recent observation that SF-enriched broccoli sprout extracts strongly inhibits N-butyl-N-(4-hydroxybutyl)nitrosamine-induced bladder cancer development, suggest that SF is a highly promising agent for bladder cancer prevention and provides a mechanistic insight into the repeated epidemiological observation that consumption of broccoli is inversely associated with bladder cancer risk and mortality.

Expanding therapeutic targets in bladder cancer: the PI3K/Akt/mTOR pathway

A complex equilibrium of biological signals exists within the human body to regulate normal cellular function and growth. Unfortunately, there are various ways in which disruption of these signaling pathways can result in uncontrollable cell growth--an important element in oncogenesis. In particular, the mammalian target of rapamycin (mTOR) pathway appears to play a central role in the development of multiple cancers, including urothelial cell carcinoma (UCC). Although often called 'a master regulator,' mTOR is but one signal in an intricate signaling cascade that controls cell growth and angiogenesis in both normal and cancerous conditions. Other important factors in this pathway include upstream activators such as phosphatidylinositol 3 kinase (PI3K) and Akt, negative regulators such as the tuberous sclerosis complex (TSC) 1/2, and downstream effectors such as p70 S6 kinase and eukaryotic initiation factor eIF4E. On the basis of its important role in tumor growth, efforts have focused on developing means to effectively target the mTOR pathway in hopes of designing new treatments for various tumor types. To address the role of mTOR pathway activity in UCC, we will first review the basic elements of the PI3K/Akt/mTOR pathway and then apply this pathway to bladder cancer oncogenesis. As will be evident, significant progress has been made in defining the role of this pathway in UCC; however, continued research into the nuances of pathway regulation and the usage of targeted inhibition in bladder cancer patients is necessary to define mTOR as a promising target in this disease.

Early results of urothelial carcinoma screening in a risk population of coke workers: urothelial carcinoma among coke workers

OBJECTIVE

To present the protocol and the early results of a urothelial carcinoma (UC) screening analysis performed in a risk population of coke workers.

METHODS

Between June 2006 and October 2008, 171 male workers (mean age 43 years), employed in a Ligurian coke plant (Italiana Coke S.r.l) and exposed to polycyclic aromatic hydrocarbons (PAHs) for a median period of 16 years, underwent screening for UC. Urological evaluation included medical history, physical examination, routine laboratory tests, urine analysis, urinary cytology and uCyt+ assay. In the event of signs and symptoms suggestive of UC or positive urinary tests, the workers were also subjected to urinary ultrasonography and cystoscopy with biopsy of any suspicious lesions.

RESULTS

Regarding the laboratory tests, 19/171 (11%) uCyt+ samples were considered inadequate and were excluded from the outcomes assessment. Overall, urine analysis, cytology and uCyt+ were positive in 18/152 (12%) subjects who showed no evidence of UC at the scheduled check-ups. No significant association was identified between marker positivity and occupational activity.

CONCLUSIONS

Our results fail to show an increased risk of UC among the coke workers evaluated. However, they will need to be confirmed in the future by a larger enrollment and a longer follow-up in order to assess the definitive risk for UC after exposure to coke.

Synthesis, biological evaluation, and structure-activity relationships of dithiolethiones as inducers of cytoprotective phase 2 enzymes

Dithiolethiones are a family of promising cancer chemopreventive agents, and induction of phase 2 enzymes is key to their chemopreventive activities. Two dithiolethiones have been evaluated in humans for cancer prevention. While some chemopreventive activities were detected in several human studies, potential side effects are a concern. Herein, we report structure-activity relationships of 25 dithiolethiones. Several compounds show exceedingly potent and bladder specific activity in phase 2 enzyme induction. Structural features responsible for such activity, as well as those inhibiting the activity, are discussed. Moreover, the compounds activate and depend on Nrf2 for their inductive activities. Nrf2 is a major transcriptional stimulator of cytoprotective genes and is critical for cancer prevention. Thus, several new dithiolethiones that are highly promising for bladder cancer prevention have been identified. Because the compounds act specifically in the bladder, the likelihood of potential systemic toxicity may be low.

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.

Inhibition of bladder cancer development by allyl isothiocyanate

Bladder cancer is one of the common human cancers and also has a very high recurrence rate. There is a great need for agents capable of inhibiting bladder cancer development and recurrence. Here, we report that allyl isothiocyanate (AITC), an ingredient of many common cruciferous vegetables, potently inhibited the proliferation of bladder carcinoma cell lines in vitro [half maximal inhibitory concentration (IC(50)) of 2.7-3.3 microM], which was associated with profound G(2)/M arrest and apoptosis. In contrast, AITC was markedly less toxic to normal human bladder epithelial cells (IC(50) of 69.4 microM). AITC was then evaluated in two rat bladder cancer models in vivo (an orthotopic model and a subcutaneous model). The orthotopic model closely mimics human bladder cancer development and recurrence. We show that a low oral dose of AITC (1 mg/kg) significantly inhibited the development and muscle invasion of the orthotopic bladder cancers but was ineffective against the subcutaneous xenografts of the same cancer cells in the same animals. This differential effect was explained by our finding that urinary levels of AITC equivalent were two to three orders of magnitude higher than that in the plasma and that its levels in the orthotopic cancer tissues were also three orders of magnitude higher than that in the subcutaneous cancer tissues. Moreover, we show that AITC is a multi-targeted agent against bladder cancer. In conclusion, AITC is selectively delivered to bladder cancer tissue through urinary excretion and potently inhibits bladder cancer development and invasion.

Vitamin D for cancer prevention: global perspective

PURPOSE

Higher serum levels of the main circulating form of vitamin D, 25-hydroxyvitamin D (25(OH)D), are associated with substantially lower incidence rates of colon, breast, ovarian, renal, pancreatic, aggressive prostate and other cancers.

METHODS

Epidemiological findings combined with newly discovered mechanisms suggest a new model of cancer etiology that accounts for these actions of 25(OH)D and calcium. Its seven phases are disjunction, initiation, natural selection, overgrowth, metastasis, involution, and transition (abbreviated DINOMIT). Vitamin D metabolites prevent disjunction of cells and are beneficial in other phases.

RESULTS/CONCLUSIONS

It is projected that raising the minimum year-around serum 25(OH)D level to 40 to 60 ng/mL (100-150 nmol/L) would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year, and three fourths of deaths from these diseases in the United States and Canada, based on observational studies combined with a randomized trial. Such intakes also are expected to reduce case-fatality rates of patients who have breast, colorectal, or prostate cancer by half. There are no unreasonable risks from intake of 2000 IU per day of vitamin D(3), or from a population serum 25(OH)D level of 40 to 60 ng/mL. The time has arrived for nationally coordinated action to substantially increase intake of vitamin D and calcium.

Alterations to the protein profile of bladder carcinoma cell lines induced by plant extract MINA-05 in vitro

Bladder cancer (BLCa) is a severe urological cancer of both men and women that commonly recurs and once invasive, is difficult to treat. MINA-05 (CK Life Sciences Int'l, Hong Kong) is a derivative of complex botanical extracts, shown to reduce cellular proliferation of bladder and prostate carcinomas. We tested the effects of MINA-05 against human BLCa cell sublines, B8, B8-RSP-GCK, B8-RSP-LN and C3, from a transitional cell carcinoma, grade IV, to determine the molecular targets of treatment by observing the cellular protein profile. Cells were acclimatised for 48 h then treated for 72 h with concentrations of MINA-05 reflecting 1/2 IC(50), IC(50) and 2 x IC(50) (n = 3) or with vehicle, (0.5% DMSO). Dose-dependant changes in protein abundance were detected and characterised using 2-dimensional electrophoresis and MS. We identified 10 proteins that underwent changes in abundance, pI and/or molecular mass in response to treatment. MINA-05 was shown to influence proteins across numerous functional classes including cytoskeletal proteins, energy metabolism proteins, protein degradation proteins and tumour suppressors, suggesting a global impact on these cell lines. This study implies that the ability of MINA-05 to retard cellular proliferation is attributed to its ability to alter cell cycling, metabolism, protein degradation and the cancer cell environment.

Occupational risk factors

The association between exposure to selected chemical carcinogens, occupations or industries and bladder cancer is well established, and it is estimated that 20-27% of bladder cancers are attributable to occupational exposures. The risk of bladder cancer stemming from an occupational exposure depends not only on compound carcinogenicity, exposure intensity and workplace characteristics, but also on individual susceptibility to these cancers. Regulatory controls in industrialized nations have resulted in a decreased burden of exposure to bladder carcinogens in the workplace. Unfortunately, the same is unlikely in many developing countries, where risky technologies may have been transferred from more developed countries, and where enforcement of regulations and worker protection are likely to be less stringent.

Endocavitary Prophylaxis of Superficial Urothelial Bladder Tumours: New Compounds

Bladder urothelial carcinoma is the fourth most frequent cancer among European men, accounting for about 7% of the total cancers. Transurethral resection (TUR) is usually indicated as the standard treatment for non-muscle invasive bladder cancer (NMIBC). However, TUR is unable to guarantee a complete eradication of Ta, T1 tumors with a recurrence rate ranging from 50 to 70%, and a progression rate to muscle invasive disease ranging from 10 to 15%.

Methods

The European Association of Urology guidelines recommend adjuvant intravesical chemotherapy after definitive diagnosis of intermediate/high risk NMIBC to reduce both recurrence and progression of the disease. To provide a comprehensive review of intravesical treatment options for NMIBC, we performed a search of the PubMed database for articles between 1980 and 2009 that reported on intravesical agents for treating this disease.

Results

A critical analysis of the findings resulting from large multicenter trials, phase I, II, III studies for pertinent novel agents and from review articles was carried out. We focused on the following issues: 1) the role of the treatment with Bacillus Calmette-Guérin (BCG) and the need of maintaining the drug schedule (with or without interferon-alpha); 2) the correct timing of adjuvant immuno- and chemotherapy; 3) the use of the novel chemotherapeutic agents; 4) the use of the novel technique of chemotherapeutic agents administration, with a particular interest on electromotive administration of mitomycin.

The changing patterns of bladder cancer in Egypt over the past 26 years

OBJECTIVE

To evaluate temporal changes in histopathological types of bladder cancer and to assess associated changes in demographic, epidemiologic, and lifestyle risk factors.

METHODS

We abstracted data from all available medical records from the National Cancer Institute of Cairo University (NCI-Cairo). Six calendar years representing 5-year periods between 1980 and 2005 were evaluated. Information on demographics, schistosomal infection, clinical symptoms of bladder cancer, and tumor pathology was abstracted.

RESULTS

During this 26-year period, important changes in the frequency of histopathological types of bladder cancer occurred. We found a statistically significant association between time period of diagnosis and histopathological type. Patients diagnosed in 2005 had a sixfold higher odds associated with transitional cell carcinoma compared to those patients diagnosed in 1980 (odds ratio (OR) 6.00 (95% CI 4.00-8.97)).

CONCLUSIONS

These data strongly suggest that the histopathological profile of bladder cancer in Egypt has changed significantly over the past 26 years. Historically, squamous cell carcinoma was the predominant form of bladder cancer in Egypt; however transitional cell carcinoma has become the most frequent type. These results corroborate findings from a few small-scale hospital-based studies which conclude that the etiology of bladder cancer in Egypt has changed significantly over the past 26 years.

Inhibition of urinary bladder carcinogenesis by broccoli sprouts

Isothiocyanates are a well-known class of cancer chemopreventive agents, and broccoli sprouts are a rich source of several isothiocyanates. We report herein that dietary administration to rats of a freeze-dried aqueous extract of broccoli sprouts significantly and dose-dependently inhibited bladder cancer development induced by N-butyl-N-(4-hydroxybutyl) nitrosamine. The incidence, multiplicity, size, and progression of bladder cancer were all inhibited by the extract, while the extract itself caused no histologic changes in the bladder. Moreover, inhibition of bladder carcinogenesis by the extract was associated with significant induction of glutathione S-transferase and NAD(P)H:quinone oxidoreductase 1 in the bladder, enzymes that are important protectants against oxidants and carcinogens. Isothiocyanates are metabolized to dithiocarbamates in vivo, but dithiocarbamates readily dissociate to isothiocyanates. We found that >70% of the isothiocyanates present in the extract were excreted in the urine as isothiocyanate equivalents (isothiocyanates + dithiocarbamates) in 12 h after a single p.o. dose, indicating high bioavailability and rapid urinary excretion. In addition, the concentrations of isothiocyanate equivalents in the urine of extract-treated rats were 2 to 3 orders of magnitude higher than those in plasma, indicating that the bladder epithelium, the major site of bladder cancer development, is most exposed to p.o. dosed isothiocyanate. Indeed, tissue levels of isothiocyanate equivalents in the bladder were significantly higher than in the liver. In conclusion, broccoli sprout extract is a highly promising substance for bladder cancer prevention and the isothiocyanates in the extract are selectively delivered to the bladder epithelium through urinary excretion.

The influence of polymorphisms of glutathione S-transferases M1 and M3 on the development of human urothelial cancer

Cigarette smoking is the most important risk factor for development of transitional cell carcinoma of the urinary bladder. The effect of polymorphisms of glutathione S-transferases M1 (GSTM1) and M3 (GSTM3) on the influence of cigarette smoking on urinary bladder carcinogenesis was investigated. In total, 293 bladder cancer patients from hospitals in Dortmund and Wittenberg as well as 176 patients without any malignancy from a Department of Surgery from Dortmund were genotyped for GSTM1 and GSTM3 according to standard PCR/RFLP methods. Smoking habits were quantified by a standardized interview. The proportion of GSTM1 negative cases was 63% in the entire bladder cancer cases group compared to 50% in controls. The GSTM3*A/*A genotype was 76% in cancer cases versus 74% in controls. Smokers and ex-smokers were overrepresented in bladder cancer cases. A significant association between smoking status and GSTM1 or GSTM3 genotype was not detected. The elevated proportion of GSTM1 negative bladder cancer cases shows an effect of this polymorphic enzyme on development of bladder cancer. In contrast to other studies, an influence of GSTM1 on the risk due to cigarette smoking was not observed.

Projecting individualized probabilities of developing bladder cancer in white individuals

PURPOSE

There has been no risk assessment model for bladder cancer (BC). We developed the first model incorporating mutagen sensitivity and epidemiologic factors to predict BC risk.

PATIENTS AND METHODS

We used epidemiologic and genetic data from a large case-control study to build the models and constructed receiver operating characteristic curves. The area under the curve (AUC) was used to evaluate model discriminatory ability. We also projected absolute risk of developing BC by taking into account competing causes of death.

RESULTS

The study included 678 white BC patients and 678 controls. Significant risk factors in the epidemiologic model included pack-years smoked and exposures to diesel, aromatic amines, dry cleaning fluids, radioactive materials, and arsenic. This model yielded good discriminatory ability (AUC = 0.70; 95% CI, 0.67 to 0.73). When mutagen sensitivity data were incorporated, the AUC increased to 0.80 (95% CI, 0.72 to 0.82). The models showed excellent concordance in the internal validation. We also computed an easy to use ordinal risk score and provided examples for projecting absolute risk.

CONCLUSION

We have developed the first risk prediction model for BC. The enhanced model integrating the genetic factor exhibited excellent discriminatory ability. Our model only requires an individual to answer a few simple questions during a clinic visit to project individualized probability. This model may be used as a basis for developing a Web-based tool for BC risk assessment. Validation of our model in an external population is an essential next step towards practical use in the clinical setting.