Water intake and bladder cancer risk in Los Angeles County

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.

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.

A systematic review of measurement methods used to estimate fluid and beverage intake in free-living, working-age adults

BACKGROUND

Beverage intake in employees is important to quantify due to the potential of dehydration to increase the risk of errors and reduced work performance. This systematic review aimed to (1) characterise existing fluid intake measurement tools used in the workplace setting or among free-living, healthy adults of working age and (2) report the current validation status of available assessment tools for use in a UK setting.

METHODS

Three electronic databases were searched for publications measuring beverage intake using a defined tool or method. Additional studies were identified by hand from trial registers, grey literature and reference lists. Eligibility was determined using predefined inclusion/exclusion criteria. Study quality was assessed using a modified Strengthening the Reporting of Observational Studies in Epidemiology framework. Narrative synthesis was performed.

RESULTS

The review identified 105 studies. The most frequently reported beverage assessment methods were total diet diaries/records (n = 22), fluid specific diaries/records (n = 18), food and fluid frequency questionnaires (n = 17), beverage-specific frequency questionnaires (n = 23) and diet recalls (n = 11). General dietary measurement tools (measuring beverages as part of total diet) were used in 60 studies, and 45 studies used a beverage-specific tool. This review identified 18 distinct dietary assessment tools, of which 6 were fluid/beverage specific. Twelve tools published relative validity for a beverage-related variable and seven tools for total daily fluid intake (from whole diet or from beverages only).

CONCLUSIONS

Several fluid intake assessment tools were identified; however, few have been fully evaluated for total beverage intake, and none in a UK working population.

Consumption of sugar-sweetened beverages and fruit juice and human cancer: a systematic review and dose-response meta-analysis of observational studies

Background: Several epidemiological studies have assessed the association of sugary drinks consumption with cancer, but the results remain controversial. Objective: We performed this analysis to evaluate possible causal relationship between sugary drinks consumption and cancer risk and mortality. Methods: We searched PubMed, Embase, and Web of Science databases in English. Observational studies evaluating the association of sugary drinks intake with cancer were included. Random-effects meta-analysis was used to calculate the risk estimates. Results: A total of 71 observational articles with 32 case-control and 39 cohort studies were included in the meta-analysis. 60 addressed cancer risk, and 11 reported cancer mortality. Compared with the lowest level, the highest level of sugar-sweetened beverages (SSB) consumption showed an increased overall cancer risk (RR=1.12 95% CI: 1.06-1.19, P=0.000) and mortality (RR=1.07 95% CI: 1.01-1.14, P=0.029), and fruit juice intake showed a positive association with cancer risk in cohort studies (RR=1.06 95% CI: 1.01-1.11, P=0.013). Subgroup analyses based on cancer type indicated that risk of breast cancer, hepatocellular carcinoma, colorectal cancer, and prostatic cancer mortality had a positive association with SSB consumption. For dose-response analysis, evidence of a linear association was found between overall cancer risk and SSB or fruit juice consumption, and the risk increase by 4% for one servings/d increment in SSB intake and 14% in fruit juice. Conclusions: Our findings suggest the consumption of sugary beverages may increase the risk and mortality of cancer, especially risk of breast cancer, hepatocellular carcinoma, colorectal cancer, and prostatic cancer, and mortality of breast cancer, though the evidence was limited.

Unexplained Variance in Hydration Study

With the collection of water-intake data, the National Health and Nutrition Examination Survey (NHANES) is becoming an increasingly popular resource for large-scale inquiry into human hydration. However, are we leveraging this resource properly? We sought to identify the opportunities and limitations inherent in hydration-related inquiry within a commonly studied database of hydration and nutrition. We also sought to critically review models published from this dataset. We reproduced two models published from the NHANES dataset, assessing the goodness of fit through conventional means (proportion of variance, R²). We also assessed model sensitivity to parameter configuration. Models published from the NHANES dataset typically yielded a very low goodness of fit R² < 0.15. A reconfiguration of variables did not substantially improve model fit, and the goodness of fit of models published from the NHANES dataset may be low. Database-driven inquiry into human hydration requires the complete reporting of model diagnostics in order to fully contextualize findings. There are several emergent opportunities to potentially increase the proportion of explained variance in the NHANES dataset, including novel biomarkers, capturing situational variables (meteorology, for example), and consensus practices for adjustment of co-variates.

Dairy Product Consumption and Bladder Cancer Risk: A Meta-Analysis

To explore the potential relationship between dairy product consumption and bladder cancer risk, we retrieved eligible studies published up to March 15, 2018, via online database search and manual review of the selected articles. Summary relative risk (RR) estimates were calculated using random-effects models based on high to low intake values. Inter-study heterogeneity was explored using stratified analyses of study design, geographic region, or whether studies adjusted for the confounders age, sex, body mass index, smoking, and education level. We extracted data from 16 studies on milk (5,193 subjects) and 10 studies on dairy products (20,434 subjects). The total study population included 220,952 individuals. Dairy product intake and bladder cancer risk were significantly associated, and milk intake and bladder cancer risk more so. Stratified analysis revealed that the trend was more pronounced in case-control studies, and in studies with impact factor <3 and in Asia. The relationship was confirmed after adjusting for sex and Newcastle-Ottawa Scale score of 7 and 8. Our study shows an inverse association between milk consumption and bladder cancer risk.

Milk and Dairy Product Consumption and Bladder Cancer Risk: A Systematic Review and Meta-Analysis of Observational Studies

Some studies have reported that milk and dairy product consumption reduces bladder cancer incidence, whereas others have reported null or opposite findings. This meta-analysis of 26 cohort and case-control studies has been conducted to pool the risk of the association between milk and dairy products and bladder cancer. A systematic search in MEDLINE, EMBASE, and the Web of Science (from inception to 30 April 2018) was conducted. Random-effects models were used to compute pooled estimates of RR for high or medium compared with low consumption of milk and dairy. Sensitivity analyses were conducted. Subgroup analyses were performed based on type of dairy, gender, geographic location, and type of study design. Random-effects meta-regression was used to evaluate other confounding factors. Overall, medium compared with low consumption was associated with lower pooled risk of bladder cancer for total dairy products (RR = 0.90; 95% CI: 0.81, 0.98), milk (RR = 0.90; 95% CI: 0.82, 0.98), and fermented dairy products (RR = 0.87; 95% CI: 0.79, 0.96). The inverse association for milk consumption was stronger in Asians (RR = 0.79; 95% CI: 0.59, 0.98) and in cohort design studies (RR = 0.85; 95% CI: 0.71, 0.99). Moreover, high compared with low consumption was significantly associated with a lower pooled risk for milk (RR = 0.89; 95% CI: 0.81, 0.98) and fermented dairy products (RR = 0.78; 95% CI: 0.61, 0.94). However, high compared with low consumption of whole milk was significantly associated with a higher risk (RR = 1.21; 95% CI: 1.04, 1.38). The statistical heterogeneity was considerable. In conclusion, the present meta-analysis suggests a decreased risk of bladder cancer associated with medium consumption of total dairy products and with medium and high consumption of milk and fermented dairy products. An increased risk of bladder cancer was observed with high consumption of whole milk. Interpretations of the results should be made with caution. This review was registered at www.crd.york.ac.uk/prospero as CRD42018097020.

Association of benign prostatic hyperplasia and subsequent risk of bladder cancer: an Asian population cohort study

OBJECTIVES

Few studies discussed the link between benign prostatic hyperplasia (BPH) and bladder cancer. We performed this cohort study to investigate whether there is an association between BPH and subsequent risk of bladder cancer.

METHODS

We identified 35,092 study subjects including 17546 BPH patients and 17546 comparisons from the National Health Insurance database. The comparison cohort was frequency matched with age and index-year. We measured subsequent bladder cancer rates (per 1000 person-years) in two cohorts. Attributable risks (ARs) was calculated based on the bladder cancer rates in two cohorts. The hazard ratios (HRs) and 95% confidence intervals (CIs) for bladder cancer were estimated via Cox proportional hazard regression.

RESULTS

BPH patients had a higher bladder cancer rate than comparisons (AR = 0.81 per 1000 person-years) and exhibited 4.69- and 4.11-fold increases in bladder cancer risk in the crude and adjusted Cox models, respectively (95% CIs = 4.15-6.99 and 2.70-6.26). The AR was highest in patients aged 65-74 years old (AR = 1.33). BPH patients with chronic kidney disease were at an elevated bladder cancer risk. Regarding the association between bladder cancer and transurethral prostatectomy (TURP), BPH patients who underwent TURP were at a higher risk of bladder cancer (AR = 1.69; HR = 6.17, 95% CI = 3.68-10.3) than those who did not (AR = 0.69; HR = 3.73, 95% CI = 2.43-5.74).

CONCLUSIONS

In this study, BPH patients were found to have an increased risk of subsequent bladder cancer. Based on the limitations of retrospective nature, further studies are needed.

SLC14A1: a novel target for human urothelial cancer

Urinary bladder cancer is the second commonly diagnosed genitourinary malignancy. Previously, bio-molecular alterations have been observed within certain locations such as chromosome 9, retinoblastoma gene and fibroblast growth factor receptor-3. Solute carrier family 14 member 1 (SLC14A1) gene encodes the type-B urea transporter (UT-B) which facilitates the passive movement of urea across cell membrane, and has recently been related with human malignancies, especially for bladder cancer. Herein, we discussed the SLC14A1 gene and UT-B protein properties, aiming to elucidate the expression behavior of SLC14A1 in human bladder cancer. Furthermore, by reviewing some well-established theories regarding the carcinogenesis of bladder cancer, including several genome wide association researches, we have bridged the mechanisms of cancer development with the aberrant expression of SLC14A1. In conclusion, the altered expression of SLC14A1 gene in human urothelial cancer may implicate its significance as a novel target for research.

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.

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.

Effect of Increased Water Intake on Urinary DNA Adduct Levels and Mutagenicity in Smokers: A Randomized Study

The association between fluid intake and bladder cancer risk remains controversial. Very little is known about to which extent the amount of water intake influences the action of excreting toxics upon the urinary system. This proof of concept trial investigates the effect of water intake on mutagenesis in smokers, a high risk population for bladder cancer. Methods. Monocentric randomized controlled trial. Inclusion Criteria. Male subjects aged 2045–45 y/o, smokers, and small drinkers (24-hour urinary volume <1 L and osmolality >700 mOsmol/kg). Outcomes. 4-ABP DNA adducts formation in exfoliated bladder cells in 24-hour urine collection and urinary mutagenicity in 24-hour urine. Test Group. Subjects consumed 1.5 L daily of the study product (EVIAN) on top of their usual water intake for 50 days. Control Group. Subjects continued their usual lifestyle habits. Results. 65 subjects were randomized. Mean age was 30 y/o and mean cigarettes per day were 20. A slight decrease in adducts formation was observed between baseline and last visit but no statistically significant difference was demonstrated between the groups. Urinary mutagenicity significantly decreased. The study shows that increasing water intake decreases urinary mutagenicity. It is not confirmed by urinary adducts formation. Further research would be necessary.

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.

Cancer risks in aluminum reduction plant workers: a review

OBJECTIVE AND METHODS

This review examines epidemiological evidence relating to cancers in the primary aluminum industry where most of what is known relates to Söderberg operations or to mixed Söderberg/prebake operations.

RESULTS AND CONCLUSIONS

Increased lung and bladder cancer risks have been reported in Söderberg workers from several countries, but not in all. After adjustment for smoking, these cancer risks still increase with cumulative exposure to benzo(a)pyrene, used as an index of coal tar pitch volatiles exposure. Limited evidence has been gathered in several cohorts for an increased risk of tumors at other sites, including stomach, pancreas, rectum/rectosigmoid junction, larynx, buccal cavity/pharynx, kidney, brain/nervous system, prostate, and lymphatic/hematopoietic tissues (in particular non-Hodgkin lymphoma, Hodgkin disease, and leukemia). Nevertheless, for most of these tumor sites, the relationship with specific exposures has not been demonstrated clearly and further follow-up of workers is warranted.

Impact of fluid intake in the prevention of urinary system diseases: a brief review

We are often told that we should be drinking more water, but the rationale for this remains unclear and no recommendations currently exist for a healthy fluid intake supported by rigorous scientific evidence. Crucially, the same lack of evidence precludes the claim that a high fluid intake has no clinical benefit. The aim of this study is to describe the mechanisms by which chronic low fluid intake may play a crucial role in the pathologies of four key diseases of the urinary system: urolithiasis, urinary tract infection, chronic kidney disease and bladder cancer. Although primary and secondary intervention studies evaluating the impact of fluid intake are lacking, published data from observational studies appears to suggest that chronic low fluid intake may be an important factor in the pathogenesis of these diseases.

Differential urinary specific gravity as a molecular phenotype of the bladder cancer genetic association in the urea transporter gene, SLC14A1

Genome-wide association studies (GWAS) identified associations between markers within the solute carrier family 14 (urea transporter), member 1 (SLC14A1) gene and risk of bladder cancer. SLC14A1 defines the Kidd blood groups in erythrocytes and is also involved in concentration of the urine in the kidney. We evaluated the association between a representative genetic variant (rs10775480) of SLC14A1 and urine concentration, as measured by urinary specific gravity (USG), in a subset of 275 population-based controls enrolled in the New England Bladder Cancer Study. Overnight urine samples were collected, and USG was measured using refractometry. Analysis of covariance was used to estimate adjusted least square means for USG in relation to rs10775480. We also examined the mRNA expression of both urea transporters, SLC14A1 and SLC14A2, in a panel of human tissues. USG was decreased with each copy of the rs10775480 risk T allele (p-trend = 0.011) with a significant difference observed for CC vs. TT genotypes (p-value(tukey) = 0.024). RNA-sequencing in the bladder tissue showed high expression of SLC14A1 and the absence of SLC14A2, while both transporters were expressed in the kidney. We suggest that the molecular phenotype of this GWAS finding is the genotype-specific biological activity of SLC14A1 in the bladder tissue. Our data suggest that SLC14A1 could be a unique urea transporter in the bladder that has the ability to influence urine concentration and that this mechanism might explain the increased bladder cancer susceptibility associated with rs10775480.

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.

Benign prostatic hyperplasia is a significant risk factor for bladder cancer in diabetic patients: a population-based cohort study using the National Health Insurance in Taiwan

BACKGROUND

Diabetic patients have a higher risk of bladder cancer and benign prostatic hyperplasia (BPH). Theoretically, BPH patients may have an increased risk of bladder cancer because residual urine in the bladder surely increases the contact time between urinary excreted carcinogens and the urothelium. However, whether BPH increases bladder cancer risk in patients with type 2 diabetes has not been studied.

METHODS

The reimbursement databases of all Taiwanese diabetic patients under oral anti-diabetic agents or insulin from 1996 to 2009 were retrieved from the National Health Insurance. An entry date was set at 1 January 2006 and a total of 547584 men with type 2 diabetes were followed up for bladder cancer incidence until the end of 2009. Incidences of bladder cancer for BPH by status and by duration were calculated and adjusted hazard ratios (95% confidence intervals) were estimated by Cox regression. The effects of diabetes duration and medications used for diabetic control in relation with bladder cancer risk were also evaluated by Cox regression in BPH men.

RESULTS

The incidences were 258.77 and 69.34 per 100,000 person-years for patients with and without BPH, respectively, adjusted hazard ratio 1.794 (1.572, 2.047). For BPH patients, those who underwent surgical procedures for BPH had a higher incidence than those who did not (355.45 vs. 250.09 per 100,000 person-years), respective adjusted hazard ratios: 2.459 (1.946, 3.109) and 1.709 (1.492, 1.958). The significantly higher risk could be demonstrated for BPH of any duration: respective adjusted hazard ratios 1.750 (1.430, 1.605), 1.844 (1.543, 2.203), 2.011 (1.680, 2.406) and 1.605 (1.341, 1.921) for BPH <1, 1-3, 3-5 and ≥ 5 years versus patients without BPH. Sensitivity analyses for patients aged ≥ 60 years and after excluding BPH patients with surgical procedures or without surgical procedures, respectively, yielded similar results. In BPH men, diabetes duration was not significantly related with bladder cancer; but metformin was consistently associated with a significantly lower risk, with adjusted hazard ratio of 0.719 (0.590, 0.875) for all ages and 0.742 (0.604, 0.912) for age ≥ 60 years.

CONCLUSIONS

BPH is a significant risk factor for bladder cancer in men with type 2 diabetes. Metformin may protect against bladder cancer in BPH men.

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.

A meta-analysis of tea consumption and the risk of bladder cancer

OBJECTIVE

Previous studies on the association between tea consumption and bladder cancer risk have only illustrated contradictory results. The role of tea in bladder carcinogenesis still remains conflicting. In order to illustrate the potential relationship between tea consumption and bladder cancer, a meta-analysis of case-control and cohort studies was conducted.

METHODS

Eligible studies were retrieved via both computerized searches and review of references. Stratified analyses on types of tea, gender, study design, ethnicity and smoking status were performed. Fixed- or random-effect models were used to summarize the estimates of OR with 95% CIs.

RESULTS

Seventeen studies were eligible for our analysis. No statistical significance was detected between tea consumption and bladder cancer risk when comparing the highest with the lowest intake of tea (OR = 0.825, 95% CI 0.652-1.043). In the subgroup of green tea, we observed it illustrated a protective effect on bladder cancer (OR = 0.814, 95% CI 0.678-0.976).

CONCLUSION

Our analysis indicated that green tea may have a protective effect on bladder cancer in Asian people. Further studies need to be conducted to better clarify the biological mechanisms.

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.

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.

Diabetes and urothelial cancer risk: the Multiethnic Cohort study

BACKGROUND

It is important to understand the adverse health sequelae that may result from the rising incidence of diabetes. Diabetics may have an increased risk for urothelial cancer but the evidence from prospective studies and ethnically diverse populations is sparse.

METHOD

We examined this association in the Multiethnic Cohort (MEC) that was conducted in Hawaii and Los Angeles with nearly 186,000 participants in five ethnic groups. Over a median 10.7 years of follow-up, 918 incident cases of urothelial cancer (89% bladder and 11% other urinary tract sites) were identified through tumor registry linkages.

RESULTS

A self-reported diagnosis of diabetes was associated with an increased risk of urothelial cancer (relative risk=1.25; 95% confidence interval: 1.04-1.50). The association was not explained by body mass index, physical activity, or smoking. There was some suggestion that the risk was higher in women, Whites and African Americans, and past smokers. The risk associated with diabetes for in situ and localized cancer was similar to that for regional and distant cancer.

CONCLUSION

This study demonstrates that the increased urothelial cancer risk with diabetes in this multiethnic population is very similar to that observed in mostly White or Asian populations. Whether or not the elevated risk is moderated by the degree of control of the hyperglycemia associated with diabetes will need to be determined in future studies.

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

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

Factors associated with low drinking water intake among adolescents: the Florida Youth Physical Activity and Nutrition Survey, 2007

There is limited information on which characteristics are associated with water intake among adolescents. This cross-sectional study examined the association between demographic, dietary, and behavioral factors and low water intake as the outcome measure. Analyses were based on the 2007 Florida Youth Physical Activity and Nutrition Survey using a representative sample of 4,292 students in grades six through eight in 86 Florida public middle schools. Multivariable logistic regression was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals for factors associated with low water intake (<3 glasses water per day). About 64% of students had low water intake. Factors significantly associated with low water intake were Hispanic ethnicity and non-Hispanic other (vs non-Hispanic white; ORs 0.79 and 0.76, respectively), drinking no 100% juice, drinking it <1 time/day, and drinking it 1 to 2 times/day (vs drinking it ≥3 times/day; ORs 1.83, 1.91, and 1.32, respectively), drinking no milk and drinking <2 glasses of milk/day (vs drinking ≥2 glasses/day; ORs 1.42 and 1.41, respectively), drinking <1 soda/day (vs drinking none; OR 1.40), drinking fruit-flavored drinks/sports drinks <1 time/day and drinking it ≥1 time/day (vs drinking none; ORs 1.49 and 1.41, respectively), eating at a fast-food restaurant ≥3 days/week (vs none; OR 1.38, respectively), not participating on team sports or participating on 1 to 2 team sports in previous 12 months (vs participating on ≥3 teams; ORs 1.77 and 1.24, respectively), and consuming snack/soda while watching television/movies "sometimes" and "most/every time" (vs never; ORs 1.65 and 2.20, respectively). The strongest factor associated with low water intake was frequent consumption of snacks/sodas while watching television/movies. Although study findings should be corroborated in other states and in a nationally representative sample, they may be useful in targeting adolescents for increased water consumption.

Tea and cancer prevention: epidemiological studies

Experimental studies have consistently shown the inhibitory activities of tea extracts on tumorigenesis in multiple model systems. Epidemiological studies, however, have produced inconclusive results in humans. A comprehensive review was conducted to assess the current knowledge on tea consumption and risk of cancers in humans. In general, consumption of black tea was not associated with lower risk of cancer. High intake of green tea was consistently associated with reduced risk of upper gastrointestinal tract cancers after sufficient control for confounders. Limited data support a protective effect of green tea on lung and hepatocellular carcinogenesis. Although observational studies do not support a beneficial role of tea intake on prostate cancer risk, phase II clinical trials have demonstrated an inhibitory effect of green tea extract against the progression of prostate pre-malignant lesions. Green tea may exert beneficial effects against mammary carcinogenesis in premenopausal women and recurrence of breast cancer. There is no sufficient evidence that supports a protective role of tea intake on the development of cancers of the colorectum, pancreas, urinary tract, glioma, lymphoma, and leukemia. Future prospective observational studies with biomarkers of exposure and phase III clinical trials are required to provide definitive evidence for the hypothesized beneficial effect of tea consumption on cancer formation in humans.

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.

Urinary tract infections and reduced risk of bladder cancer in Los Angeles

We investigated the association between urinary tract infections (UTIs) and transitional cell carcinoma of the bladder in a population-based case–control study in Los Angeles covering 1586 cases and age-, gender-, and race-matched neighbourhood controls. A history of bladder infection was associated with a reduced risk of bladder cancer among women (odds ratio (OR), 0.66; 95% confidence interval (CI), 0.46–0.96). No effect was found in men, perhaps due to power limitations. A greater reduction in bladder cancer risk was observed among women with multiple infections (OR, 0.37; 95% CI, 0.18–0.78). Exclusion of subjects with a history of diabetes, kidney or bladder stones did not change the inverse association. A history of kidney infections was not associated with bladder cancer risk, but there was a weak association between a history of other UTIs and slightly increased risk among men. Our results suggest that a history of bladder infection is associated with a reduced risk of bladder cancer among women. Cytotoxicity from antibiotics commonly used to treat bladder infections is proposed as one possible explanation.