Fluid consumption and the risk of bladder cancer: results of a multicenter case-control study

Low daily water intake profile-is it a contributor to disease?

Few previous review articles have focused on the associations between inadequate daily water intake (LOW) or urinary biomarkers of dehydration (UD; low urine volume or high urine osmolality) and multiple diseases. Accordingly, we conducted manual online searches (47 key words) of the PubMed, Embase, and Google Scholar databases with these inclusion criteria: English language, full-text, peer reviewed, no restriction on research design, and three publications minimum. Initially, 3,903 articles were identified based on their titles and abstracts. Evaluations of full length .pdf versions identified 96 studies that were acceptable for inclusion. We concluded that the evidence is insufficient or conflicting for seven disorders or diseases (i.e. suggesting the need for additional clarifying research) and it is lacking for all-cause mortality. Differential characterizations among women and men have been reported in the results of nine studies involving five diseases. Finally, the evidence for associations of LOW or UD is strong for both kidney stones and type 2 diabetes with hyperglycemia. This suggests that great public health value (i.e. reduced disease risk) may result from increased daily water intake-a simple and cost-effective dietary modification.

Somatic Versus Germline: A Case Series of Three Children With ATM-Mutated Medulloblastoma

Somatic versus Germline-A Case Series of Three Children with ATM- mutated Medulloblastoma.

Tea Drinking and the Risk of Carcinoma of the Urinary Bladder: A Meta-Analysis

Objective

For evaluation of the correlation between tea drinking and the risk of carcinoma of the urinary bladder.

Methods

By searching PubMed, Embase, and Cochrane Library databases, the original studies on tea drinking and carcinoma of the urinary bladder risk were collected, the data were extracted, and meta-analysis package 5.2-0 of R language was used for meta-analysis.

Results

This study contained 11 researches, composed of 7686 patients and 10320 controls. Tea drinking was not linked to carcinoma of the urinary bladder risk (OR:1.02, 95%CI: 0.95-1.11).

Conclusion

Tea drinking may not be linked to carcinoma of the urinary bladder, but more definitive results are needed from higher-quality trials.

Cigarette smoking and risk of bladder cancer: a dose-response meta-analysis

INTRODUCTION

The disease burden of bladder cancer is increasing worldwide; therefore, to deal with this situation, many studies on bladder cancer have been carried out extensively. Among these studies, the risk factors studies may provide a possible way to reduce the incidence of bladder cancer. Meta-analyses and original researches have confirmed that smoking is a risk factor of bladder cancer. However, the specific dose-response relationship between smoking and bladder cancer risk was still unclear. This meta-analysis addresses this research gap by summarizing the accumulated evidences, quantitatively.

METHODS

Relevant studies were obtained by searching PubMed, Embase and Web of Science database since inception until August 10, 2021, without restrictions. To obtain more comprehensive data, reference lists of identified articles were also browsed. Studies that reported risk estimates (relative risks (RR) or odds ratio (OR)) with 95% confidence intervals (CIs) focusing on the association between cigarette smoking and risk of bladder cancer were included in a dose-response meta-analysis.

RESULTS

A non-linear dose-response relationship was confirmed between cigarette smoking and risk of bladder cancer on the basis of 8 cohorts and 44 case-control studies. The summary relative risk of developing bladder cancer for 1 more cigarettes/day (7 cohorts and 24 case-control studies) was 1.039 (95% CI 1.038-1.040, I² = 0%), for 1 more pack-year (3 cohorts and 21 case-control studies) was 1.017(95% CI 1.016-1.019, I² = 0%) and for 1 more year of exposure (16 case-control studies) was 1.021 (95% CI 1.020-1.023, I² = 0%).

CONCLUSION

A positive non-linear dose-response relationship is confirmed between all smoking intensity, pack-years of smoking, smoking duration(years) and the risk of bladder cancer, but the plateau only occurred when smoking intensity reached 20 cigarettes/day. Further studies should report more detailed results, including those for subtypes of gender, age, region and be stratified by other risk factors to rule out residual confounding.

Associations between inflammasome-related gene NLRP3 Polymorphisms (rs10754558 and rs35829419) and risk of bladder cancer in a Chinese population

Background

NLRP3 inflammasome as a component of immune system has been found related to several cancers, but no study has assessed NLRP3 polymorphisms on risk of bladder cancer (BC). We aim to investigate whether NLRP3 polymorphisms are associated with the risk and clinical features of bladder cancer (BC) in a Chinese population.

Methods

Genotype frequency of two commonly studied NLRP3 SNPs (rs10754558 and rs35829419) was examined in 154 patients with BC and the 308 healthy controls. NLRP3 gene polymorphisms were genotyped by polymerase chain reaction‐restriction fragment length polymorphism method.

Results

The distribution frequencies of GG, AG+GG, GG, and G allele in NLRP3 (rs10754558) genotypes were significantly different between case and control group (OR = 2.296, P = .022; OR = 1.598, P = .020; OR = 1.998, P = .049; OR = 1.557, P = .006), but no statistical difference existed for rs35829419. Among smokers and alcohol drinkers, for rs10754558, individuals with AG, GG, and GG+AG genotypes had a higher BC risk compared with individuals with AA; for rs35829419, individuals with variant genotypes (AG and GG+AG) had a stronger risk of developing BC compared with individuals with AA (all P < .05). In stratified analyses of tumor size and tumor node metastasis, AG or GG genotypes of rs10754558 and rs35829419 SNPs were associated with BC risk (both P < .05).

Conclusion

NLRP3 polymorphisms (rs10754558 and rs35829419) were related to BC risk and tumor size and lymph node metastasis, especially among smokers and alcohol drinkers.

Coffee consumption and risk of bladder cancer: a pooled analysis of 501,604 participants from 12 cohort studies in the BLadder Cancer Epidemiology and Nutritional Determinants (BLEND) international study

Recent epidemiological studies have shown varying associations between coffee consumption and bladder cancer (BC). This research aims to elucidate the association between coffee consumption and BC risk by bringing together worldwide cohort studies on this topic. Coffee consumption in relation to BC risk was examined by pooling individual data from 12 cohort studies, comprising of 2601 cases out of 501,604 participants. Pooled multivariate hazard ratios (HRs), with corresponding 95% confidence intervals (CIs), were obtained using multilevel Weibull regression models. Furthermore, dose-response relationships were examined using generalized least squares regression models. The association between coffee consumption and BC risk showed interaction with sex (P-interaction < 0.001) and smoking (P-interaction = 0.001). Therefore, analyses were stratified by sex and smoking. After adjustment for potential confounders, an increased BC risk was shown for high (> 500 ml/day, equivalent to > 4 cups/day) coffee consumption compared to never consumers among male smokers (current smokers: HR = 1.75, 95% CI 1.27-2.42, P-trend = 0.002; former smokers: HR = 1.44, 95% CI 1.12-1.85, P-trend = 0.001). In addition, dose-response analyses, in male smokers also showed an increased BC risk for coffee consumption of more than 500 ml/day (4 cups/day), with the risk of one cup (125 ml) increment as 1.07 (95% CI 1.06-1.08). This research suggests that positive associations between coffee consumption and BC among male smokers but not never smokers and females. The inconsistent results between sexes and the absence of an association in never smokers indicate that the associations found among male smokers is unlikely to be causal and is possibly caused by residual confounding of smoking.

Impact of alcohol consumption on the risk of developing bladder cancer: a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies that investigated alcohol consumption in relation to the risk of bladder cancer (BCa) have demonstrated inconsistent results. We conducted a systematic review and meta-analysis of the literature to investigate the association of alcohol including different types of alcoholic beverages consumption with the risk of BCa.

MATERIALS AND METHODS

A systematic search of Web of Science, Medline/PubMed and Cochrane library was performed in May 2018. Studies were considered eligible if they assessed the risk of BCa due to alcohol consumption (moderate or heavy dose) and different types of alcoholic beverages (moderate or heavy dose) in multivariable analysis in the general population (all genders, males or females) or compared with a control group of individuals without BCa.

STUDY DESIGN

observational cohorts or case-control.

RESULTS

Sixteen studies were included in this meta-analysis. Moderate and heavy alcohol consumption did not increase the risk of BCa in the entire population. Sub-group and sensitivity analyses revealed that heavy alcohol consumption increased significantly the risk of BCa in the Japanese population, RR 1.31 (95% CI 1.08-1.58, P < 0.01) in the multivariable analysis, and in males RR of 1.50 (95% CI 1.18-1.92, P < 0.01), with no significant statistical heterogeneity. Moreover, heavy consumption of spirits drinks increased the risk of BCa in males, RR 1.42 (95% CI 1.15-1.75, P < 0.01).

CONCLUSION

In this meta-analysis, moderate and heavy alcohol consumption did not increase the risk of bladder cancer significantly. However, heavy consumption of alcohol might increase the risk of BCa in males and in some specific populations.

Fluid intake-to-bed time, nocturia frequency and the risk of urothelial carcinoma of the bladder: a case-control study

Objectives: To clarify the potential role of fluid intake-to-bed time and nocturia frequency on bladder cancer risk in a hospital-based case-control study with Chinese people.

Materials and Methods: Four hundred and seven patients with histologically diagnosed bladder cancer and 400 matched controls were enrolled in this study. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression model.

Results: After adjustment for potential confounders, the fluid intake-to-bed time was associated with a decreased risk of BCa, with an OR of 0.586 (95% CI= 0.375-0.916, ≤1h) and 0.257 (95% CI= 0.162-0.407, >1h). The adjusted OR of BCa for subjects with more nocturia frequency (≥2 times) was 2.268 (95 % CI= 1.481-3474), compared to those with no nocturia.

Conclusion: We suggested strong protective effect of long fluid intake-to-bed time on BCa risk, especially in ones with ≥2 times nocturia frequency. These results provide evidence for identifying high-risk individuals and modifying their behaviors and lifestyle.

Total fluid consumption and risk of bladder cancer: a meta-analysis with updated data

With meta-analysis we tented to reveal the potential relationship between daily fluid consumption and bladder cancer risk, and to find out a recommendation on daily fluid intake. Databases of the Web of Science, PubMed and EMBASE were searched then 21 case-control and 5 cohort studies were included. Stratified analyses on gender, region, time of subjects recruiting and fluid quantity were performed as well as dose-response meta-analysis. Comparing the highest exposure category with the lowest in each study, no association appeared when all data pooled together (p=0.50), but a significant OR of 1.46 (1.02-2.08, p=0.04) was found in male subgroup. For different regions, the summarized OR was 1.44 (1.10-1.89) in American case-control studies, 1.87 (1.20-2.90) in European male subgroup and 0.24 (0.10-0.60) in Asia. There was a significant relationship that each increment 1000ml daily consumption would increase the risk by 28.6% in European male (p=0.007). Similarly every additional 1000ml consumption may increase the OR by 14.9% in American people but the association wasn't that strong (p=0.057). Stratified analyses showed fluid consumption over 3000ml/day in American residents and 2000ml/day in European male resulted in OR>1 with statistical significance. In conclusion, a relationship between higher fluid intake and higher bladder cancer risk was observed in European male and American residents and a limitation to <2000ml and <3000ml per day are recommended respectively.

Acetamides: chemotherapeutic agents for inflammation-associated cancers

Now clear evidences are available to support the hypothesis that inflammation accelerates the conditions including events and molecules that reach to various types of cancers. Inflammation is a normal response to infection containing the innate and adaptive immune systems. However, when allowed to continue, unresolved, perturbation of cellular microenvironment takes place; therefore, it leads to adaptations in genes that are linked to cancer. In addition, a lot of data are accessible confirming the concept that tumour microenvironment is orchestrated by various inflammatory cells and goes to neoplastic process and finally invasion, migration and metastasis. However, infiltrations of leucocytes lead to angiogenesis, propagation and invasion. An inflammatory microenvironment that perhaps fostering impact of angiogenesis include cytokines, chemokines, enzymes and growth factors that play key role for expansion and invasion of cancer cells. This insight highlights the pathogenesis of inflammation-associated cancers and also touches and fosters the role of acetamides for the treatment and chemoprevention of carcinomas that are allied with inflammation.

Tea Consumption and Risk of Bladder Cancer: A Dose-Response Meta-Analysis

Background and Objective: Controversial results of the association between tea (black tea, green tea, mate, and oolong tea) consumption and risk of bladder cancer were reported among epidemiological studies. Thus, we performed a meta-analysis of observational studies to investigate the association. Methods: We searched the PubMed and Embase for studies of tea consumption and bladder cancer that were published in any language up to March, 2016. Cohort or case-control studies were included in the meta-analysis. All statistical analyses were performed in Stata 12.0 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationship between tea consumption and risk of bladder cancer. Results: Totally, 25 case-control studies (15 643 cases and 30 795 controls) and seven prospective cohort studies (1807 cases and 443 076 participants) were included. The meta-analysis showed that tea consumption was not significantly associated with bladder cancer risk (OR = 0.96, 95% CI 0.86-1.06) (in a comparison of highest vs. lowest category). No non-linearity association was observed between tea consumption and bladder cancer risk (P = 0.51 for non-linearity). Specific analysis for black tea, green tea, and mate yielded similar results. The dose-response analysis showed the summary OR for an increment of 1 cup/day of tea consumption was 1.01 (95% CI 0.97-1.05). Conclusion: Results based on current meta-analysis indicated that no significant association was observed between tea consumption and risk of bladder cancer.

Coffee consumption and bladder cancer: a meta-analysis of observational studies

Controversial results of the association between coffee consumption and bladder cancer (BC) risk were reported among epidemiological studies. Therefore, we conducted this meta-analysis to clarify the association. Relevant studies were identified according to the inclusion criteria. Totally, 34 case-control studies and 6 cohort studies were included in our meta-analysis. The overall odds ratio (OR) with 95% confidence interval (CI) between coffee consumption and BC risk was 1.33 (95% CI 1.19 to 1.48). The summary ORs of BC for an increase of 1 cup of coffee per day were 1.05 (95% CI 1.03 to 1.06) for case-control studies and 1.03 (95% CI 0.99 to 1.06) for cohort studies. The overall ORs for male coffee drinkers, female coffee drinkers and coffee drinkers of both gender were 1.31 (95% CI: 1.08 to 1.59), 1.30 (95% CI: 0.87 to 1.96) and 1.35 (95% CI: 1.20 to 1.51). Compared with smokers (OR = 1.24, 95% CI: 0.91 to 1.70), non-smokers had a higher risk (OR = 1.72, 95% CI: 1.25 to 2.35) for BC. Results of this meta-analysis suggested that there was an increased risk between coffee consumption and BC. Male coffee drinkers and non-smoking coffee drinkers were more likely to develop BC.

Relationship between bladder cancer and total fluid intake: a meta-analysis of epidemiological evidence

Objectives

Epidemiological findings regarding the association between total fluid intake and bladder cancer risk have yielded varying results. Our objective is to examine the possible associations between total fluid intake and bladder cancer risk.

Methods

Databases searched include the EMBASE and PUBMED, from inception to February 2014, with no limits on study language. We also reviewed the reference lists of identified studies. Stratified analyses were performed. A random-effect model was used to summarize the estimates of odds ratio (OR) with 95% confidence intervals (CI).

Results

Overall,17 case-control and four cohort studies were included. The overall OR of bladder cancer for the highest versus the lowest fluid intake was 1.06 (95% CI: 0.88-1.27). In the subgroup analyses, the overall ORs for coffee, green, and black tea intake were 1.17 (95% CI: 1.03-1.33), 0.76 (95% CI: 0.66-0.95), and 0.80 (95% CI: 0.65-0.97), respectively. A significantly decreased risk was observed in Asian people (OR 0.27; 95% CI: 0.10-0.72). Among smokers, a suggestive inverse association was observed between total fluid intake and overall bladder cancer risk (OR 0.80; 95% CI: 0.62-1.02).

Conclusions

Although this meta-analysis suggested that greater consumption of fluid may have a protective effect on bladder cancer in Asian people, there was no convincing evidence on this association because of the limitations of the individual trials.

Fluid intake, genetic variants of UDP-glucuronosyltransferases, and bladder cancer risk

Background:

Results of studies of fluid consumption and its association with bladder cancer have been inconsistent. Few studies have considered modification effects from genetic variants that may interact with the type of consumed fluids. UDP-glucuronosyltransferases (UGTs), which are membrane-bound conjugating enzymes, catalyse the transformation of hydrophobic substrates to more water-soluble glucuronides to facilitate renal or biliary excretion. Whether genetic variants in UGTs could modulate the association between fluid intake and bladder cancer has not been studied.

Methods:

We conducted a case–control study with 1007 patients with histopathologically confirmed bladder cancer and 1299 healthy matched controls. Fluid intake and epidemiologic data were collected via in-person interview. Multivariate unconditional logistic regression was used to estimate odds ratios (ORs) and the 95% confidence intervals (95% CI).

Results:

After adjustment for potential confounders, high quantity of total fluid intake (⩾2789 vs <1696 ml per day) conferred a 41% increased risk of bladder cancer (OR=1.41; 95% CI=1.10–1.81). Specific fluids such as regular soft drinks and decaffeinated coffee were also associated with increased risks, whereas tea, wine, and liquor were associated with decreased risks. Among 83 single-nucleotide polymorphisms in the UGT gene family, 18 were significantly associated with bladder cancer risk. The most significant one was rs7571337, with the variant genotype conferring a 29% reduction in risk (OR=0.71; 95% CI=0.56–0.90).

Conclusions:

Total and specific fluid intakes are associated with bladder cancer risk in the study population and that genetic variants of UGT genes could modulate the effects. These results facilitate identification of high-risk individuals and have important implications in bladder cancer prevention.

Evaluation of a bladder cancer cluster in a population of criminal investigators with the Bureau of Alcohol, Tobacco, Firearms and Explosives-part 1: the cancer incidence

This study investigated a bladder cancer cluster in a cohort of employees, predominately criminal investigators, participating in a medical surveillance program with the United States Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) between 1995 and 2007. Standardized incidence ratios (SIRs) were used to compare cancer incidences in the ATF population and the US reference population. Seven cases of bladder cancer (five cases verified by pathology report at time of analysis) were identified among a total employee population of 3,768 individuals. All cases were white males and criminal investigators. Six of seven cases were in the 30 to 49 age range at the time of diagnosis. The SIRs for white male criminal investigators undergoing examinations were 7.63 (95% confidence interval = 3.70-15.75) for reported cases and 5.45 (2.33-12.76) for verified cases. White male criminal investigators in the ATF population are at statistically significant increased risk for bladder cancer.

Tea consumption and risk of bladder cancer: a meta-analysis

Background

Tea consumption has been reported to be associated with an decreased risk of several types of cancers. However, the results based on epidemiological studies on the association of tea consumption with bladder cancer were inconsistent. This meta-analysis was undertaken to evaluate the relationship between tea consumption and bladder cancer risk.

Methods

Eligible studies were retrieved via both computer searches and review of references. The summary relative risk (RR) with 95% confidence interval (CI) was calculated.

Results

Twenty three studies met the inclusion criteria of the meta-analysis. No association with bladder cancer was observed in either overall tea consumption group (OR =0.94, 95% CI 0.85-1.04) or subgroups stratified by sex, study design, geographical region or tea types.

Conclusions

Our findings did not support that tea consumption was related to the decreased risk of bladder cancer.

A dose-response meta-analysis of coffee consumption and bladder cancer

BACKGROUND

A number of studies have examined the association between coffee consumption and risk of bladder cancer, but uncertainty about the dose-response relationship remains.

MATERIALS AND METHODS

A comprehensive search was performed to identify all observational studies providing quantitative estimates between bladder cancer risk and coffee consumption. Dose-response relationship was assessed by restricted cubic spline model and bivariate random-effect meta-regression.

RESULTS

23 case-control studies with 7690 cases and 13,507 controls, and 5 cohort studies with 700 cases and 229,099 participants, met the inclusion criteria. Compared with non-drinkers and for case-control studies, the pooled smoking-adjusted RRs(95% CI) of bladder cancer were 1.07(1.02-1.13) for 1 cup/day, 1.15(1.05-1.26) for 2 cups/day, 1.22(1.08-1.38) for 3 cups/day, and 1.29(1.12-1.48) for 4 cups/day. For cohort studies, the pooled smoking-adjusted RRs of bladder cancer were 1.09(95% CI, 0.89-1.34) for 1 cup/day, 1.13(95% CI, 0.82-1.55) for 2 cups/day, 1.09(95% CI, 0.77-1.56) for 3 cups/day, and 1.01(95% CI, 0.69-1.48) for 4 cups/day.

CONCLUSIONS

Although data from case-control studies suggested that coffee was a risk factor for bladder cancer, there was no conclusive evidence on this association because of inconsistencies between case-control and cohort studies.

Reexamination of total fluid intake and bladder cancer in the Health Professionals Follow-up Study Cohort

It has been hypothesized that high fluid intake may reduce contact time between carcinogens and bladder epithelium and consequently reduce carcinogenesis. Epidemiologic studies examining fluid intake and bladder cancer have been extremely inconsistent, ranging from strong inverse to strong positive associations. The authors reevaluated the association between fluid intake and bladder cancer among 47,909 participants in the prospective Health Professionals Follow-up Study over a period of 22 years. During follow-up (1986-2008), 823 incident bladder cancer cases were diagnosed. Information on fluid intake was collected by using the food frequency questionnaire at baseline and every 4 years thereafter. Cox proportional hazard regression analysis was used to adjust for risk factors for bladder cancer. Total fluid intake was inversely associated with bladder cancer when the analysis was based on the baseline diet (relative risk = 0.76, 95% confidence interval: 0.60, 0.97), comparing the highest total daily fluid intake quintile (>2,531 mL/day) with the lowest quintile (<1,290 mL/day) (P(trend) = 0.01). However, no association was detected when the analysis was based on recent diet or cumulative updated diet. The updated analysis for total fluid intake and bladder cancer was attenuated compared with the original findings from the first 10-year follow-up period.

Chemoprevention in bladder cancer: What's new?

Bladder cancer is the sixth most common tumour in Canada and ranks eighth in terms of cancer mortality. Up to now, management of this condition relied mostly on surgical and intravesical treatments once the disease is established. Chemoprevention is an attractive option to prevent the disease in high-risk populations and may well reduce the costs related to its treatment. This review examines the available data on chemoprevention strategies in bladder cancer, with special emphasis on randomized controlled trials when available.

Fluid intake and the risk of urothelial cell carcinomas in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Results from previous studies investigating the association between fluid intake and urothelial cell carcinomas (UCC) are inconsistent. We evaluated this association among 233,236 subjects in the European Prospective Investigation into Cancer and Nutrition (EPIC), who had adequate baseline information on water and total fluid intake. During a mean follow-up of 9.3 years, 513 first primary UCC occurred. At recruitment, habitual fluid intake was assessed by a food frequency questionnaire. Multivariable hazard ratios were estimated using Cox regression stratified by age, sex and center and adjusted for energy intake, smoking status, duration of smoking and lifetime intensity of smoking. When using the lowest tertile of intake as reference, total fluid intake was not associated with risk of all UCC (HR 1.12; 95%CI 0.86-1.45, p-trend = 0.42) or with risk of prognostically high-risk UCC (HR 1.28; 95%CI 0.85-1.93, p-trend = 0.27) or prognostically low-risk UCC (HR 0.93; 95%CI 0.65-1.33, p-trend = 0.74). No associations were observed between risk of UCC and intake of water, coffee, tea and herbal tea and milk and other dairy beverages. For prognostically low-risk UCC suggestions of an inverse association with alcoholic beverages and of a positive association with soft drinks were seen. Increased risks were found for all UCC and prognostically low-risk UCC with higher intake of fruit and vegetable juices. In conclusion, total usual fluid intake is not associated with UCC risk in EPIC. The relationships observed for some fluids may be due to chance, but further investigation of the role of all types of fluid is warranted.

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.

Alcohol, coffee, and bladder cancer risk: a review of epidemiological studies

The objective was to review epidemiological studies that evaluated the association between consumption of coffee and alcohol and urinary bladder cancer. We searched the Medline database for observational studies of bladder neoplasms that included information on coffee or alcohol drinking, and looked for papers quoted as references in reviews of risk factors for bladder cancer and in studies that had been selected for inclusion. Results from epidemiological studies allow excluding a strong association between coffee and bladder cancer. Several studies reported a moderate increase in risk in coffee drinkers as compared with nondrinkers, but no trend with dose has been established. Epidemiological data on alcohol drinking and bladder cancer are suggestive of no association, although findings were not always consistent. For both habits, an explanation of the moderate increase in risk observed in some investigations might be attributed to residual confounding by smoking, or to an association between alcohol, coffee, and yet unidentified risk factors for bladder cancer.

Nutrition, total fluid and bladder cancer

Bladder cancer is a major health concern for older males in Western populations. About 30 years ago there was a suggestion that nutrition may have a role in the aetiology of the disease. Although the literature has been accumulating since then, owing to heterogeneity between studies results have often been inconsistent and unclear. The aim of this paper was to present an updated summary of the scientific evidence on the association between nutrition, total fluid intake and bladder cancer. A search of computerized databases, PubMed, ISI, Embase and Cochrane Library, was conducted to identify all epidemiological studies published between 1966 and October 2007. The level of scientific evidence for the various nutritional factors and total fluid intake was ranked according to the number of studies reporting a statistically significant association and the existence of mechanistic evidence. The levels of association were based on a ranking of statistically significant relative risks. Fruit and yellow-orange vegetables, particularly carrots and selenium, are probably associated with a moderately reduced risk of bladder cancer. Citrus fruits and cruciferous vegetables were also identified as having a possible protective effect. Possible risk factors are salted and barbecued meat, pork, total fat, pickled vegetables, salt, soy products, spices and artificial sweeteners. No clear association could be determined for beef, eggs, processed meats and total fluid intake. In conclusion, specific fruit and vegetables may act to reduce the risk of bladder cancer. Future studies on bladder cancer should investigate the effect of food categorization, amount and gender.

Coffee and alcohol consumption and bladder cancer

Epidemiological studies on coffee, alcohol and bladder cancer risk published up to 2007 were reviewed. Coffee drinkers have a moderately higher relative risk of bladder cancer compared to non-drinkers. The association may partly be due to residual confounding by smoking or dietary factors, but the interpretation remains open to discussion, although the absence of dose and duration-risk relations weighs against the presence of a causal association. Most studies of alcohol and bladder cancer found no association, with some studies finding a direct and other an inverse one. This again may be due to differential confounding effect of tobacco smoking--the major risk factor for bladder cancer--in various populations. Thus, epidemiological findings on the relation between alcohol drinking and bladder cancer exclude any meaningful association.

Coffee consumption, genetic susceptibility and bladder cancer risk

OBJECTIVE

We evaluated the bladder cancer risk associated with coffee consumption in a case-control study in Spain and examined the gene-environment interactions for genetic variants of caffeine-metabolizing enzymes.

METHODS

The analyses included 1,136 incident cases with urothelial carcinoma of the urinary bladder and 1,138 controls. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for area, age, gender, amount of cigarette smoking, and years since quitting among former smokers.

RESULTS

The OR (95% CI) for ever consumed coffee was 1.25 (0.95-1.64). For consumers of 1, 2, 3, and 4 or more cups/day relative to never drinkers, OR were, respectively, 1.24 (0.92-1.66), 1.11 (95% CI 0.82-1.51), 1.57 (1.13-2.19), and 1.27 (0.88-1.81). Coffee consumption was higher in smokers compared to never smokers. The OR for drinking at least 4 cups/day was 1.13 (0.61-2.09) in current smokers, 1.57 (0.86-2.90) in former smokers, and 1.23 (0.55-2.76) in never smokers. Gene-coffee interactions evaluated in NAT2, CYP1A2, and CYP2E1-02 and CYP1A1 were not identified after adjusting for multiple testing.

CONCLUSION

We observed a modest increased bladder cancer risk among coffee drinkers that may, in part, be explained by residual confounding by smoking. The findings from the gene-coffee interactions need replication in further studies.

Cultured milk, yogurt, and dairy intake in relation to bladder cancer risk in a prospective study of Swedish women and men

BACKGROUND

Findings from epidemiologic studies of the effect of dairy foods (mainly milk) on the risk of bladder cancer have been inconsistent.

OBJECTIVE

We aimed to examine the association between the intake of cultured milk and other dairy foods and the incidence of bladder cancer in a prospective, population-based cohort.

DESIGN

We prospectively followed 82,002 Swedish women and men who were cancer-free and who completed a 96-item food-frequency questionnaire in 1997. Incident cases of bladder cancer were identified in the Swedish cancer registries.

RESULTS

During a mean follow-up of 9.4 y, 485 participants (76 women and 409 men) were diagnosed with bladder cancer. Total dairy intake was not significantly associated with risk of bladder cancer [> or =7.0 servings/d compared with < 3.5 servings/d: multivariate rate ratio (RR) = 0.87; 95% CI: 0.66, 1.15; P for trend = 0.33]. However, a statistically significant inverse association was observed for the intake of cultured milk (sour milk and yogurt). The multivariate RRs for the highest category of cultured milk intake (> or =2 servings/d) compared with the lowest category (0 serving/d) were 0.62 (95% CI: 0.46, 0.85; P for trend = 0.006) in women and men combined, 0.55 (95% CI: 0.25, 1.22; P for trend = 0.06) in women, and 0.64 (95% CI: 0.46, 0.89; P for trend = 0.03) in men. The intake of milk or cheese was not associated with bladder cancer risk.

CONCLUSION

These findings suggest that a high intake of cultured milk may lower the risk of developing bladder cancer.

Water intake and bladder cancer risk in Los Angeles County

The overall evidence of an association between fluid intake and bladder cancer is not entirely consistent. We examined the fluid intake-bladder cancer relationship in the Los Angeles bladder cancer case-control study. A total of 1,586 cases and their age-, sex-, and race-matched neighborhood controls were interviewed in-person from 1987 to 1999. Information on total fluid intake was derived from the consumption of specific fluids including water, coffee, tea, alcohol, milk, juice, hot chocolate and soda. Total fluid intake was not associated with bladder cancer. Daily water intake was associated with a slight decrease in bladder cancer risk, with the protection more pronounced among women (p for trend = 0.039) than among men (p for trend = 0.62). Compared to drinking <1 glass of water per day, drinking > or =6 glasses/day was associated with 0.91 (95% confidence interval, 0.67-1.22) times the risk of bladder cancer among all subjects, 0.94 (0.67-1.32) times the risk among men, and 0.69 (0.36-1.33) times the risk among women. The water intake-bladder cancer association also seemed to be modified by daytime urination frequency with significant inverse association among subjects who urinated > or =6 times/day (p for trend = 0.015), but not among those who urinated less frequently. Similarly, the protection from water intake was confined to women who did not experience nocturia and to men who did. Results from our study suggest that water intake may be associated with a slight reduction in bladder cancer risk.

Total fluid and water consumption and the joint effect of exposure to disinfection by-products on risk of bladder cancer

BACKGROUND

Findings on water and total fluid intake and bladder cancer are inconsistent; this may, in part, be due to different levels of carcinogens in drinking water. High levels of arsenic and chlorinated by-products in drinking water have been associated with elevated bladder cancer risk in most studies. A pooled analysis based on six case-control studies observed a positive association between tap water and bladder cancer but none for nontap fluid intake, suggesting that contaminants in tap water may be responsible for the excess risk.

OBJECTIVES

We examined the association between total fluid and water consumption and bladder cancer risk, as well as the interaction between water intake and trihalomethane (THM) exposure, in a large case-control study in Spain.

METHODS

A total of 397 bladder cancer cases and 664 matched controls were available for this analysis. Odds ratios (OR) were estimated using unconditional logistic regression, controlling for potential confounders.

RESULTS

Total fluid intake was associated with a decrease in bladder cancer risk [OR = 0.62; 95% confidence interval (CI), 0.40-0.95 for highest vs. lowest quintile comparison]. A significant inverse association was observed for water intake (for > 1,399 vs. < 400 mL/day, OR = 0.47; 95% CI, 0.33-0.66; p for trend < 0.0001), but not for other individual beverages. The inverse association between water intake and bladder cancer persisted within each level of THM exposure; we found no statistical interaction (p for interaction = 0.13).

CONCLUSION

Findings from this study suggest that water intake is inversely associated with bladder cancer risk, regardless of THM exposure level.

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

Urinary bladder cancer (UBC) ranks ninth in worldwide cancer incidence. It is more frequent in men than in women. We review the main established/proposed factors, both environmental and genetic, associated with bladder cancer etiology and prognosis. Data were extracted from previous reviews and original articles identified from PubMed searches, reference lists, and book chapters dealing with the reviewed topics. Evaluation and consensus of both the contribution of each factor in bladder cancer burden and the appropriateness of the available evidences was done during an ad hoc meeting held during the 18th Congress of the European Society for Urological Research. Cigarette smoking and specific occupational exposures are the main known causes of UBC. Phenacetin, chlornaphazine and cyclophosphamide also increase the risk of bladder cancer. Chronic infection by Schistosoma haematobium is a cause of squamous cell carcinoma of the bladder. NAT2 slow acetylator and GSTM1 null genotypes are associated with an increased risk of this cancer. Vegetables and fresh fruits protect against this tumor. Regarding prognosis, there is little knowledge on the predictive role of environmental exposures and genetic polymorphisms on tumor recurrence and progression and patient's death. Although active tobacco smoking is the most commonly studied factor, no definitive conclusion can be drawn from the literature. More research is needed regarding the effect of complex etiological factors in bladder carcinogenesis. Subgroup analysis according to stage, grade, and molecular features may help in identifying specific etiological and prognostic factors involved in different bladder cancer progression pathways.

Sources of variability in levels and exposure to trihalomethanes

In the framework of a cohort study of pregnant women conducted in Brittany (France), we assessed the exposure to trihalomethanes (THM) during pregnancy in a subset by evaluating (1) potential sources of variability in household THM levels; (2) the between- and within-subject variability in THM levels; (3) THM levels in swimming pools; and (4) the role of water-related habits on total THM uptake. We visited 109 women from the ongoing cohort study at home for an interview and collection of tap water from October to December 2004. Forty-three of them were re-contacted to obtain a second tap water sample in April-May 2005. We designed a questionnaire to collect individual information on source and amount of drinking water, frequency of showering, bathing, and swimming pool attendance, and household characteristics. We obtained 282 THM measurements, 152 specifically for the study and 130 from a regulatory agency. Personal information and environmental data were combined using two methodologies (method 1 using regulatory data and method 2 using our THM measurements) with a different set of assumptions. We calculated ingestion, showering, bathing, and swimming pool THM uptakes and added up those uptakes to calculate total THM uptake. Average THM levels from our measurements in October, November-December, and April-May were 61.3, 45.1, and 54.5 microg/l, respectively. Geographical variability was low and characteristics of the household did not influence THM levels. Within-subject variability in THM levels was three times higher than between-subject variability. Average THM level in swimming pools was 80.4 microg/l. Average water consumption during pregnancy was 1.9l/day. The source of the household drinking water was 90% bottled, 8% municipal, and 2% from other sources. Forty-seven per cent attended swimming pools during pregnancy. Using method 1, the geometric mean of total THM uptake was 0.93 microg/day. Showering contributed 64%, swimming in pools 23%, bathing 12%, and drinking water 1% to the total THM uptake. In a setting with low geographical variability and limited environmental measurements, individual data is highly relevant to determine personal THM exposure and uptake. In a population that mainly drinks bottled water (e.g., pregnant women), individual THM uptakes are dominated by inhalation and dermal absorption during, showering, swimming in pools, and bathing.

Mechanisms of disease: The epidemiology of bladder cancer

Mortality from bladder cancer has shown downward trends over the last 2 decades in several western European countries (albeit 10-15 years later than similar trends in the US), but is still increasing in some eastern European countries. Tobacco smoking and occupational exposure to aromatic amines are the two major established environmental risk factors for bladder cancer. Controlling exposure to these factors has been an important contributor to the reduction in bladder cancer mortality, particularly among men. Diet could influence bladder carcinogenesis, as many compounds contained in foods--and their metabolites--are excreted through the urinary tract. Fruit and vegetable consumption was inversely related with bladder cancer in many studies, but no consistent association has emerged between intake of related micronutrients and reduced risk of bladder cancer. Other widely investigated lifestyle habits are probably not associated with risk of developing bladder cancer (e.g. coffee consumption, artificial sweetener use, hair dyes) or are difficult to assess (e.g. fluid intake). Infections and stones in the urinary tract might cause chronic irritation of the bladder epithelium, and thus increase bladder cancer risk. First-degree relatives of bladder cancer patients have a 50-100% increased relative risk of developing the disease, a risk that could be even higher when the proband is diagnosed at an early age.

Prevention of Bladder Cancer: A Review

INTRODUCTION

Bladder cancer represents an ideal tumor model to test and apply cancer prevention strategies. In addition to reviewing the epidemiology of transitional cell carcinoma (TCC), we review the current status and the future directions of bladder cancer prevention.

MATERIALS AND METHODS

A literature review of peer-reviewed articles which address bladder cancer prevention was performed.

RESULTS

Pre-clinical and limited clinical data suggest that bladder cancer is responsive to efforts to delay or prevent its development in at-risk patients, and in reducing the risk of recurrence in patients with established disease. Many epidemiologic studies, however, investigating natural products, such as vitamins and herbal compounds, lack conclusive evidence of their chemopreventive effects.

CONCLUSIONS

While many agents hold promise in the prevention of bladder cancer, none currently can be recommended as proven chemoprevention strategies. Improving the accuracy of patient risk assessment and identification of surrogate endpoint biomarkers are crucial to the testing of these strategies. Efficient study design will ensure rapid and substantial advances in the chemoprevention of bladder cancer.

Total and specific fluid consumption as determinants of bladder cancer risk

We pooled the data from 6 case-control studies of bladder cancer with detailed information on fluid intake and water pollutants, particularly trihalomethanes (THM), and evaluated the bladder cancer risk associated with total and specific fluid consumption. The analysis included 2,729 cases and 5,150 controls. Odds ratios (OR) and 95% confidence intervals (CI) for fluid consumption were adjusted for age, gender, study, smoking status, occupation and education. Total fluid intake was associated with an increased risk of bladder cancer in men. The adjusted OR for 1 l/day increase in intake was 1.08, (95% CI 1.03-1.14, p-value for linear trend <0.001), while no trend was observed in women (OR=1.04, 0.94-1.15; p-value=0.7). OR was 1.33 (1.12-1.58) for men in the highest category of intake (>3.5 l/day) as compared to those in the lowest (<or=2 l/day). An increased risk was associated with intake of tap water. OR for >2 l/day vs. <or=0.5 l/day was 1.46 (1.20-1.78), with a higher risk among men (OR=1.50, 1.21-1.88). No increased risk was observed for the same intake groups of nontap water in men (OR=0.97, 0.77-1.22) or in women (OR=0.85, 0.50-1.42). Increased bladder cancer risks were observed for an intake of >5 cups of coffee daily vs. <5 and for THM exposure, but neither exposure confounded or modified the OR for tap water intake. The association of bladder cancer with tap water consumption, but not with nontap water fluids, suggests that carcinogenic chemicals in tap water may explain the increased risk.

Does Ozonation of Drinking Water Reduce the Risk of Bladder Cancer?

BACKGROUND

Epidemiologic studies of drinking water disinfection byproducts have focused primarily on the carcinogenic potential of chlorination byproducts. Because drinking water has been ozonated in France for decades, we were able to assess the carcinogenic risk of the disinfection byproducts generated by both ozonation and chlorination.

METHODS

We used data from a case-control study of bladder cancer conducted between 1985 and 1987 in 7 French hospitals. We compared 281 cases and 272 controls for whom we could reconstruct at least 70% of the residential exposure to drinking water contaminants over a 30-year period.

RESULTS

When we took potential confounders and exposure to chlorination byproducts into account, the risk of bladder cancer decreased as duration of exposure to ozonated water increased (OR = 0.60 [95% CI = 0.3-1.3] for 1-9 years; OR = 0.31 [0.1-0.7] for 10 years or more). Simultaneously, the risk of bladder cancer increased with duration of exposure to chlorinated surface water and with the estimated trihalomethane content of the water. Our data suggest that ozonation reduces the risk associated with the chlorination of surface water and that ozonation alone could have an independent beneficial effect on bladder cancer risk.

CONCLUSIONS

Our results are consistent with experimental evidence that ozonation in combination with chlorination decreases the concentration of trihalomethane in treated water and eliminates some of the mutagenicity of raw water.

Disinfection byproducts and bladder cancer: a pooled analysis

BACKGROUND

Exposure to disinfection byproducts in drinking water has been associated with an increased risk of bladder cancer. We pooled the primary data from 6 case-control studies of bladder cancer that used trihalomethanes as a marker of disinfection byproducts.

METHODS

Two studies were included from the United States and one each from Canada, France, Italy, and Finland. Inclusion criteria were availability of detailed data on trihalomethane exposure and individual water consumption. The analysis included 2806 cases and 5254 controls, all of whom had measures of known exposure for at least 70% of the exposure window of 40 years before the interview. Cumulative exposure to trihalomethanes was estimated by combining individual year-by-year average trihalomethane level and daily tap water consumption.

RESULTS

There was an adjusted odds ratio (OR) of 1.24 in men exposed to an average of more than 1 microg/L (ppb) trihalomethanes compared with those who had lower or no exposure (95% confidence interval [CI] = 1.09-1.41). Estimated relative risks increased with increasing exposure, with an OR of 1.44 (1.20-1.73) for exposure higher than 50 microg/L (ppb). Similar results were found with other indices of trihalomethane exposure. Among women, trihalomethane exposure was not associated with bladder cancer risk (0.95; 0.76-1.20).

CONCLUSIONS

These findings strengthen the hypothesis that the risk of bladder cancer is increased with long-term exposure to disinfection byproducts at levels currently observed in many industrialized countries.

Foods and beverages in relation to urothelial cancer: case-control study in Japan

BACKGROUND

The roles of several foods and beverages in the development of bladder cancer remain unclear.

METHODS

We undertook a hospital-based case-control study at Aichi Cancer Center Hospital, Japan. Subjects included 124 men and women (bladder cancer cases) with newly diagnosed cancers of the renal pelvis (n = 5), ureter (n = 6) or bladder (n = 113) and 620 age- and sex-matched, cancer-free outpatients (controls) presenting at the hospital in the period from 1994 to 2000. Smoking-adjusted odds ratios (OR) were estimated to assess the strength of associations between self-reported intake of foods or drinks and bladder cancer risk, using conditional logistic models.

RESULTS

We found a decreased risk in relation to frequent intake of green-yellow vegetables; the OR for the highest intake score compared with the lowest was 0.54 (95% confidence interval [CI] 0.29-0.99). The OR for carrot intake of >/=5 times/week compared with </=1-3 times/month was 0.41 (95% CI 0.16-1.01) and a decreasing risk with increasing consumption of green vegetables was also detected (P for trend = 0.063). Inverse associations between black tea, eggs and meat and risk were also suggested, whereas moderate drinkers of green tea (5-9 cups/day) showed an elevated risk. Coffee and milk consumption did not appear to exert any influence.

CONCLUSIONS

Those with an increased risk of bladder cancer, such as smokers, may benefit from increasing their consumption of green-yellow vegetables.

Fluid intake and risk of bladder and other cancers

There are appreciable differences in total fluid intake at the individual and population level, and substantial difficulties in obtaining valid measures of fluid intake. Epidemiological studies have examined the association between fluid intake and different types of cancer. For bladder cancer, fluid consumption has been associated with a moderate increase of risk in some studies, including a multicentric case-control study from the United States, based on about 3000 cases, with a decrease in others, including the Health Professional Follow-up study, or with no material association. The evidence, therefore, is far from consistent. Sources and components of fluids were also different across different types studies. From a biological point of view, a decreased fluid intake could result in a greater concentration of carcinogens in the urine or in a prolonged time of contact with the bladder mucosa because of less frequent micturition. Carcinogenic or anticarcinogenic components of various beverages excreted in the urine may also play a role in the process. It has been suggested that fluid consumption has a favorable effect on colorectal cancer risk. Fluid intake may reduce colon cancer risk by decreasing bowel transit time and reducing mucosal contact with carcinogens. Low fluid intake may also compromise cellular concentration, affect enzyme activity in metabolic regulation, and inhibit carcinogen removal. However, epidemiological data are inadequate for evaluation. Data are sparse and inconsistent for other neoplasms, including breast cancer. The fluid constituent of foods, confounding, interactions and possible influences of specific types of beverages should be investigated further. In conclusion therefore the association between total fluid intake and cancer risk remains still open to debate.

Lifestyle issues and genitourinary tumours

A variety of lifestyle factors, including physical activity, artificial sweeteners, alcohol consumption and smoking, have been reported to contribute to the risk of developing urological malignancies. A great number of epidemiological studies suggest that sports and physical activity may have a preventive influence on genitourinary tumours, especially on the incidence of prostate cancer. Smoking appears to be the most relevant lifestyle factor significantly increasing both incidence and mortality from bladder cancer. Furthermore, there is evidence implicating an association between tobacco use and kidney cancer. In contrast, prostate and testicular cancers are unlikely to be linked to tobacco use. As far as alcohol is concerned, most studies indicate that neither amount nor type of alcohol seems to be clearly associated with a risk of developing urological malignancies. However, some more recent cohort studies suggest a moderately increased risk for prostate and bladder cancer for specific types of alcohol. On the other hand, there is evidence that moderate alcohol consumption may even protect women from developing renal cancer. Since the introduction of artificial sweeteners, reports of potential cancer risks have circulated periodically through the mass media. The wide distribution of these agents and the fact that mostly combinations of the different compounds are added to a broad variety of food, drinks, drugs, and hygiene products complicates a systematic analysis of their potential impact on the development of urological malignancies. Nevertheless, so far not a single study has convincingly demonstrated a statistically significant risk of bladder cancer due to the consumption of artificial sweeteners. This survey demonstrates that the individual assessment of lifestyle factors not only may identify groups with an increased risk for urological malignancies but also clearly displays a potential for tumour prevention.

"Drink at least eight glasses of water a day." Really? Is there scientific evidence for "8 x 8"?

Despite the seemingly ubiquitous admonition to "drink at least eight 8-oz glasses of water a day" (with an accompanying reminder that beverages containing caffeine and alcohol do not count), rigorous proof for this counsel appears to be lacking. This review sought to find the origin of this advice (called "8 x 8" for short) and to examine the scientific evidence, if any, that might support it. The search included not only electronic modes but also a cursory examination of the older literature that is not covered in electronic databases and, most importantly and fruitfully, extensive consultation with several nutritionists who specialize in the field of thirst and drinking fluids. No scientific studies were found in support of 8 x 8. Rather, surveys of food and fluid intake on thousands of adults of both genders, analyses of which have been published in peer-reviewed journals, strongly suggest that such large amounts are not needed because the surveyed persons were presumably healthy and certainly not overtly ill. This conclusion is supported by published studies showing that caffeinated drinks (and, to a lesser extent, mild alcoholic beverages like beer in moderation) may indeed be counted toward the daily total, as well as by the large body of published experiments that attest to the precision and effectiveness of the osmoregulatory system for maintaining water balance. It is to be emphasized that the conclusion is limited to healthy adults in a temperate climate leading a largely sedentary existence, precisely the population and conditions that the "at least" in 8 x 8 refers to. Equally to be emphasized, lest the message of this review be misconstrued, is the fact (based on published evidence) that large intakes of fluid, equal to and greater than 8 x 8, are advisable for the treatment or prevention of some diseases and certainly are called for under special circumstances, such as vigorous work and exercise, especially in hot climates. Since it is difficult or impossible to prove a negative-in this instance, the absence of scientific literature supporting the 8 x 8 recommendation-the author invites communications from readers who are aware of pertinent publications.