Risk factors for urinary bladder carcinoma in postmenopausal women. The Iowa Women's Health Study

Non-occupational physical activity and risk of cardiovascular disease, cancer and mortality outcomes: a dose-response meta-analysis of large prospective studies

OBJECTIVE

To estimate the dose-response associations between non-occupational physical activity and several chronic disease and mortality outcomes in the general adult population.

DESIGN

Systematic review and cohort-level dose-response meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science and reference lists of published studies.

ELIGIBILITY CRITERIA

Prospective cohort studies with (1) general population samples >10 000 adults, (2) ≥3 physical activity categories, and (3) risk measures and CIs for all-cause mortality or incident total cardiovascular disease, coronary heart disease, stroke, heart failure, total cancer and site-specific cancers (head and neck, myeloid leukaemia, myeloma, gastric cardia, lung, liver, endometrium, colon, breast, bladder, rectum, oesophagus, prostate, kidney).

RESULTS

196 articles were included, covering 94 cohorts with >30 million participants. The evidence base was largest for all-cause mortality (50 separate results; 163 415 543 person-years, 811 616 events), and incidence of cardiovascular disease (37 results; 28 884 209 person-years, 74 757 events) and cancer (31 results; 35 500 867 person-years, 185 870 events). In general, higher activity levels were associated with lower risk of all outcomes. Differences in risk were greater between 0 and 8.75 marginal metabolic equivalent of task-hours per week (mMET-hours/week) (equivalent to the recommended 150 min/week of moderate-to-vigorous aerobic physical activity), with smaller marginal differences in risk above this level to 17.5 mMET-hours/week, beyond which additional differences were small and uncertain. Associations were stronger for all-cause (relative risk (RR) at 8.75 mMET-hours/week: 0.69, 95% CI 0.65 to 0.73) and cardiovascular disease (RR at 8.75 mMET-hours/week: 0.71, 95% CI 0.66 to 0.77) mortality than for cancer mortality (RR at 8.75 mMET-hours/week: 0.85, 95% CI 0.81 to 0.89). If all insufficiently active individuals had achieved 8.75 mMET-hours/week, 15.7% (95% CI 13.1 to 18.2) of all premature deaths would have been averted.

CONCLUSIONS

Inverse non-linear dose-response associations suggest substantial protection against a range of chronic disease outcomes from small increases in non-occupational physical activity in inactive adults. PROSPERO registration number CRD42018095481.

Association of metabolic syndrome and the risk of bladder cancer: A prospective cohort study

Background

Metabolic syndrome (MetS) and its components have been shown as risk factors for several solid cancers. However, current epidemiological evidence about the relevance of MetS and bladder cancer risk was limited.

Methods

We conducted a prospective cohort study of 476,986 participants with undiagnosed bladder cancer based on the UK Biobank. MetS was defined as the presence of at least three of the five selected indicators: hypertension, central obesity, raised triglyceride, reduced HDL-cholesterol, and raised fasting plasma glucose. Bladder cancer has been identified through contact with the British Cancer Registry (median follow-up time: 6.6 years). We assessed hazard ratio (HR) and 95% confidence interval (CI) through Cox proportional hazard regression after adjusting for demographic and lifestyle factors. Non-linear associations for individual MetS components were assessed by the restricted cubic spline method.

Results

During a follow-up of 3,112,566 person-years, 487 cases of bladder cancer were ascertained. MetS (HR = 1.32, 95% CI = 1.08-1.61), central obesity (HR = 1.39, 95% CI = 1.15-1.68), dyslipidemia for HDL cholesterol (HR = 1.31, 95% CI = 1.04-1.66), and hyperglycemia (HR = 1.44, 95% CI = 1.16-1.79) were associated with elevated risk of bladder cancer. Bladder cancer risk increased with the number of MetS components. In stratified analyses, MetS showed similar effects in bladder cancer independently with sex, age, cigarette and alcohol use, physical activity, and dietary factors. Higher waist circumference, BMI, fasting blood glucose, and glycosylated hemoglobin were independently associated with increased risk of bladder cancer, with no evidence against non-linearity.

Conclusion

MetS might be an independent risk factor for bladder cancer. Our findings highlighted the importance of individualized management of MetS components for preventing bladder cancer.

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.

Physical activity and risk of bladder cancer among postmenopausal women

Physical activity is associated with decreased risk for many cancers. Studies on the association between physical activity and risk of bladder cancer are limited, and findings are inconsistent. Postmenopausal women (mean age = 63.3) were recruited into the Women's Health Initiative from 1993 to 1998. Self-reported baseline information on physical activity and other covariates were available in 141 288 participants. Incident bladder cancer cases were collected through 2018 and centrally adjudicated. Hazard ratios (HRs) and 95% confidence intervals (CIs) were determined by Cox proportional hazard regression models. Effect modification due to smoking was assessed. During an average of 18.5 years of follow-up, 817 bladder cancer cases were identified. Compared to physically inactive women, those who engaged in ≥15 MET-hours/week of total physical activity, ≥8.75 MET-hours/week of walking or ≥11.25 MET-hours/week of moderate to vigorous physical activity had lower risk of bladder cancer (HR = 0.74, 95% CI: 0.59-0.94, P for linear trend = .02; HR = 0.79, 95% CI: 0.63-0.98, P for linear trend = .03; and HR = 0.76, 95% CI: 0.61-0.94, P for linear trend = .02, respectively). No effect modification was found by smoking status (P for interaction = .06, 0.91 and 0.27, respectively). We found that total physical activity, walking and moderate to vigorous physical activity were inversely associated with bladder cancer incidence among postmenopausal women in a dose-response manner. Physical activity may play a potential role in the primary prevention of bladder cancer. Further studies with objective measurements of physical activity are needed to confirm these findings.

Lifestyle associated factors and risk of urinary bladder cancer: A prospective cohort study from Norway

A number of lifestyle associated factors, such as high body mass index (BMI), low physical activity, and related metabolic disorders, are associated with increased risk of cancer at several sites. For urinary bladder cancer (BC), such studies show inconsistent results, which could result from inadequate adjustment for smoking and occupational exposure. In the population‐based Janus Cohort (n = 292 851), we investigated the independent and combined impact of BMI, physical activity, blood pressure, and blood lipids on the risk of BC, by thorough adjustment for smoking and potential occupational exposure. We used cox proportional hazard regression to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the associations between the lifestyle associated factors and BC risk. The associations observed were dependent on smoking status and gender. Among men, diastolic blood pressure (DBP) (HR 1.07, 95% CI 1.02‐1.12) and systolic blood pressure (SBP) (HR 1.04, 95% CI 1.01‐1.07) were positively associated with BC risk. Stratification by smoking status revealed a positive association between DBP and BC risk in never smokers (HR 1.14, 95% CI 1.00‐1.30), while no association was seen for current and former smokers. A risk score, integrating information across the lifestyle factors was positively associated with BC risk in men (p_trend = 0.043). In women, physical activity was associated with a decreased BC risk, but only among never smokers (HR 0.65, 95% CI 0.45‐0.94). In conclusion, relations between lifestyle associated factors and BC risk were most evident in never smokers, suggesting that smoking dominates the relation in current smokers.

The association between type 2 diabetes mellitus and bladder cancer risk among postmenopausal women

INTRODUCTION

Evidence on the association between diabetes and risk of bladder cancer has been controversial. In addition, findings on the associations between duration of diabetes, diabetes treatment, and risk of bladder cancer have been inconsistent.

METHODS

A total of 148,208 participants in Women's Health Initiative study were included. Information on diabetes status, diabetes duration, and treatment was collected both at baseline and during follow-up. Information on potential confounders including age, race/ethnicity, education, occupation, family history of cancer, smoking status, alcohol consumption, total physical activity, body mass index, and daily dietary intake were collected at baseline. Bladder cancer cases were collected and confirmed by a centralized review of pathology reports. Cox proportional hazard models with time-varying covariates were used to examine associations of diabetes status, duration of diabetes, and diabetes treatment with bladder cancer risk.

RESULTS

During a median follow-up of 18.5 years, 865 bladder cancer cases were identified. There were no significant associations of diabetes, duration of diabetes, or diabetes treatment with risk of bladder cancer. Participants with prevalent diabetes did not have significantly higher risk of bladder cancer compared with those without diabetes.

CONCLUSION

Diabetes was not significantly associated with risk of bladder cancer among postmenopausal women.

The diagnostic and prognostic roles of serum irisin in bladder cancer

BACKGROUND

Egypt is among the countries with the highest incidence of bladder cancer (BC). Adipokines involved in BC development. This study aimed to examine the diagnostic and prognostic roles of irisin in BC through its function as an adipokine.

PATIENTS AND METHODS

This study included 150 subjects; 75 patients newly diagnosed as BC and 75 apparently healthy subjects. Serum irisin levels were quantified by enzyme-linked immunosorbent assay.

RESULTS

Serum irisin levels exhibited significantly lower levels in BC patients compared to controls (1.07 [0.51-1.96] and 1.8 [0.5-2.44] µg/mL), respectively (P < 0.001). Serum irisin was positively correlated with BMI (r = 0.386, P = 0.001) and negatively correlated with serum cholesterol (r = -0.58, P < 0.0001). Irisin had 74.7% sensitivity and 90.7% specificity at a cutoff point of ≤1.2 µg/mL. Serum irisin levels reduction can predict the BC stages, when adjusted for BMI and serum cholesterol level, serum irisin had an adjusted odds ratio of 14 (P = 0.001). Low serum irisin patients had a higher mortality rate when compared to those with high levels (38.2% vs 5%).

CONCLUSION

BC patients had significantly lower levels of serum irisin. Serum irisin showed acceptable performance criteria in BC diagnosis. It had a limited role in BC grading but showed a decreasing trend in different BC stages. Serum irisin seems to be an excellent diagnostic and prognostic marker for BC.

Association between coffee consumption and risk of bladder cancer in a meta-analysis of 16 prospective studies

Background

Current evidence remains equivocal as to whether and how consumption of coffee may be associated with risk of bladder cancer, and potential influence of confounding by smoking on this association is yet to be elucidated. We conducted an updated meta-analysis of prospective studies to address these issues.

Methods

Relevant studies were identified by searching PubMed and EMBASE databases from inception to April 2019. A random-effects model was used to estimate summary relative risk (RR) with corresponding 95% confidence interval (CI) of bladder cancer associated with coffee consumption.

Results

The final analysis included 16 prospective studies comprising 2,122,816 participants and 11,848 bladder cancer cases. Overall, coffee consumption was not associated with risk of bladder cancer (RR _high-vs-low = 1.07, 95% CI: 0.96–1.20). The lack of association persisted in the strata defined by sex or participants’ smoking status. Meta-regression analyses identified the number cases (P_difference = 0.06) and the degree of adjustment for smoking (P_difference = 0.04) as potential sources of heterogeneity. There was an increased risk of bladder cancer related to higher coffee consumption among studies with fewer cases (RR _high-vs-low = 1.38, 95% CI: 1.05–1.81) and among those with poorer adjustment for smoking (RR _high-vs-low = 1.48, 95% CI: 1.14–1.93). Results were similar in the dose-response analyses (RR _{1 cup/d} = 1.01, 95% CI: 0.98–1.03).

Conclusion

Best evidence available to date does not support an independent association between coffee consumption and bladder cancer risk. Some direct associations observed in individual studies may be a result of residual confounding by smoking.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12986-019-0390-3.

The Correlation Between Bladder Cancer and Obesity, Overweight, Physical Inactivity, and Tobacco Use: An Ecological Study in Asian Countries

BACKGROUND

Bladder cancer is the ninth most common cancer in the world.

OBJECTIVES

This study aimed to determine the correlation between age-standardized incidence rates of bladder cancer and some risk factors in Asian countries through an extensive ecological analysis.

METHODS

This ecological study evaluated the correlation between age-standardized incidence rates of bladder cancer and obesity, overweight, physical inactivity, and tobacco use in 30 Asian countries. To determine the factors that were significantly related to age-standardized incidence rate of bladder cancer, a univariate analysis was performed using simple linear regression. In the next step, variables with p-values less than 0.25 were entered into a multivariate linear regression model.

RESULTS

The incidence of bladder cancer was higher in countries with higher prevalence of overweight (r2 = 0.36, p < 0.001), obesity (r2 = 0.34, p = 0.001), current daily tobacco use (r2 = 0.17, p = 0.03), and physical inactivity (r2 = 0.13, p = 0.04). The results of multiple regression analysis indicated a direct correlation between the incidence of bladder cancer and overweight (β = 0.15, p < 0.001) and current daily tobacco use (β = 0.21, p = 0.001).

CONCLUSIONS

There was a significant relationship between the incidence of bladder cancer and overweight and current daily tobacco use. Further epidemiological studies are needed to confirm this relationship.

The association between metabolic syndrome and bladder cancer susceptibility and prognosis: an updated comprehensive evidence synthesis of 95 observational studies involving 97,795,299 subjects

Background

The association between metabolic syndrome (MS) and bladder cancer (BC) was not fully investigated, and most primary studies and pooled analyses were only focused on certain specific components.

Objective

To further investigate this issue and obtain more precise findings, we conducted this updated evidence synthesis of published studies, which involved not only MS components but also the MS in its entirety.

Materials and methods

We searched the PubMed, EMBASE, and Web of Science databases for observational studies on the association between BC susceptibility and/or mortality, and MS and its components. We extracted data from included studies, evaluated heterogeneity, and performed meta-analytic quantitative syntheses.

Results

A total of 95 studies with 97,795,299 subjects were included in the present study. According to the results, MS significantly increased the risk of BC (risk ratio [RR]=1.11, 95% CI=1.00–1.23); diabetes significantly increased the risk of BC (RR=1.29, 95% CI=1.19–1.39) and associated with poor survival (RR=1.24, 95% CI=1.08–1.43). Excessive body weight was associated with increased susceptibility (RR=1.07, 95% CI=1.02–1.12), recurrence (RR=1.46, 95% CI=1.18–1.81), and mortality (RR=1.17, 95% CI=1.00–1.37). As indicated by cumulative meta-analysis, sample size was inadequate for the association between BC susceptibility and MS, the association between BC recurrence and excessive body weight, and the association between BC survival and diabetes. The sample size of the meta-analysis was enough to reach a stable pooled effect for other associations.

Conclusion

Diabetes and excessive body weight as components of MS are associated with increased susceptibility and poor prognosis of BC. Uncertainty remains concerning the impact of overall MS, hypertension, and dyslipidemia on BC susceptibility and prognosis, for which further investigations are needed.

A Prospective Investigation of Coffee Drinking and Bladder Cancer Incidence in the United States

BACKGROUND

In 1991, coffee was classified as a group 2B carcinogen, possibly carcinogenic to humans, based on limited epidemiologic evidence of a positive association with bladder cancer. In 2016, the International Agency for Research on Cancer downgraded this classification due to lack of evidence from prospective studies particularly for never smokers.

METHODS

Baseline coffee drinking was assessed with a food frequency questionnaire in the NIH-AARP prospective cohort study. Among 469,047 US adults, who were cancer free at baseline, 6,012 bladder cancer cases (5,088 men and 924 women) were identified during >6.3 million person-years of follow-up. Multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI), with non-coffee drinkers as the reference group.

RESULTS

Coffee drinking was positively associated with bladder cancer in models adjusted for age and sex (HR for ≥4 cups/d relative to coffee nondrinkers = 1.91, 95% CI = 1.70, 2.14; P trend < 0.0001). However, the association was substantially attenuated after adjustment for cigarette smoking and other potential confounders (HR for ≥4 cups/d relative to coffee nondrinkers = 1.18, 95% CI = 1.05, 1.33; P trend = 0.0007). Associations were further attenuated after additional adjustment for lifetime smoking patterns among the majority of the cohort with this available data (P trend = 0.16). There was no evidence of an association among never smokers (P trend = 0.84).

CONCLUSIONS

Positive associations between coffee drinking and bladder cancer among ever smokers but not never smokers suggest that residual confounding from imperfect measurement of smoking or unmeasured risk factors may be an explanation for our positive findings.

Association of body mass index with bladder cancer risk: a dose-response meta-analysis of prospective cohort studies

Prospective epidemiologic studies on the association between body mass index (BMI) and bladder cancer yielded inconsistent findings. This study sought to quantitatively summarize the evidence by performing a dose-response meta-analysis on prospective cohort studies. Eligible studies were retrieved via PubMed and Embase databases, and by manual review of the references. Linear and nonlinear trend analyses were conducted to explore the relationships between BMI and bladder cancer risk. Meta-analyses on the categories of overweight and obesity were also conducted. The summary relative risk (SRR) was estimated. Heterogeneity across the studies was explored through subgroup analyses based on gender, age, year of publication, sample size, assessment of BMI, geographic location, physical activity and family history of cancer. A total of 14 prospective cohort studies involving 12,642 cases were included. Result of the dose-response analysis showed a nonlinear positive relationship between BMI and bladder cancer (SRR = 1.03, 95% CI: 1.01-1.06, P-nonlinearity =0.031), suggesting that per 5 kg/m2 increment on BMI corresponded to a 3.1 % increase of bladder cancer risk, especially BMI exceed 30kg/m2.Furthermore, significant positive association was also observed between obesity category and bladder cancer risk (SRR: 1.10, 95%CI: 1.03-1.17). In summary, this dose-response meta-analysis suggests a nonlinear positive association between BMI and bladder cancer risk. Further studies are required to confirm these findings and elucidate the pathogenic mechanisms.

The association between coffee consumption and bladder cancer incidence in a pooled analysis of the Miyagi Cohort Study and Ohsaki Cohort Study

Recent epidemiological studies of the association between coffee consumption and the risk of bladder cancer have yielded conflicting results. The aim of the present study was to examine the association between coffee consumption and the incidence of bladder cancer on the basis of pooled data from two cohort studies carried out in Miyagi Prefecture, northeastern Japan. We delivered self-administered questionnaires inquiring about the frequency of coffee consumption and other lifestyle factors in 1990 for the Miyagi Cohort Study and in 1994 for the Ohsaki Cohort Study. We followed 73 346 individuals from both cohorts and identified 274 cases of bladder cancer during 17.6 years for the Miyagi Cohort Study and 13.3 years for the Ohsaki Cohort Study. The multivariate-adjusted hazard ratios (95% confidence intervals) of bladder cancer incidence for the individuals who drank coffee occasionally, 1-2 cups/day, and 3 or more cups/day compared with never drinkers were 1.22 (0.90-1.66), 0.88 (0.61-1.26), and 0.56 (0.32-0.99), respectively (Ptrend=0.04). The inverse association remained even after stratification for smoking status. These data indicate that there is a significant inverse association between coffee consumption and the risk of bladder cancer.

Diabetes mellitus and the risk of bladder cancer: A PRISMA-compliant meta-analysis of cohort studies

BACKGROUND

Epidemiologic studies have reported inconsistent results regarding the relationship between diabetes mellitus (DM) and the incidence of bladder cancer. This comprehensive systematic review and meta-analysis explored and evaluated this relationship in participants with different characteristics.

METHODS

Studies indexed in the PubMed, Embase, and the Cochrane Library databases that compared bladder cancer incidence mortality between DM and non-DM participants were included in the present study. The relative risks (RRs) of a random-effects model were used to assess these associations.

RESULTS

The final analysis included 21 cohort studies, involving a total of 13,505,643 participants. Overall, DM was associated with an increased risk of bladder cancer or cancer mortality when compared with non-DM participants (RR: 1.23; 95% confidence interval [CI]: 1.12-1.35; P < .001). Furthermore, DM had a harmful impact on subsequent bladder cancer risk in men compared with those without DM (RR: 1.23; 95% CI: 1.06-1.42; P = .005), whereas no significant relationship was observed between DM and bladder cancer in women (RR: 1.24; 95% CI: 0.95-1.61; P = .119). There was no significant gender difference for this relationship (ratio of RR: 0.99; 95% CI: 0.73-1.34; P = .958). In addition, cancer incidence (RR: 1.21; 95% CI: 1.09-1.35; P < .001) and cancer mortality (RR: 1.25; 1.17-1.35; P < .001) both increased in DM patients. Finally, smoking status and follow-up duration might also affect this relationship in men and women.

CONCLUSIONS

The findings of this study indicated that DM was associated with elevated bladder cancer or cancer mortality risk, especially in men. This relationship in women requires further exploration.

Parity and bladder cancer risk: a dose-response meta-analysis

Background

Multiple studies have reported evidence of an inverse association between parity and bladder cancer risk. However, a comprehensive and quantitative assessment of this association has never been conducted. We conducted this study to clarify this issue.

Methods

Systematic search of PubMed and Embase was performed to identify all the studies. Studies were selected based on strict screening with inclusion and exclusion criteria. Summary relative risks (RR) with 95% confidence intervals (CI) were calculated by using a fixed-effect model, and the generalized least squares trend estimation was employed to compute study-specific RR and 95% CI per live birth increase. Heterogeneity and publication bias were also evaluated.

Results

Twelve studies (6,214 cases and 2,693,350 non-cases) were eligible in this meta-analysis. The pooled RR of bladder cancer for parous versus nulliparous women was 0.76 (95% CI: 0.70–0.82). Results were similar in the studies that adjusted for BMI(RR = 0.66; 95% CI: 0.53–0.81), cigarette smoking (RR = 0.67; 95% CI: 0.57–0.79), and age (RR = 0.77; 95% CI: 0.71–0.84). The dose-response meta-analysis showed a lower bladder cancer risk (RR = 0.95; 95% CI: 0.92–0.98) for each live birth increase in parous women. No evidence of publication bias or significant heterogeneity was detected in the above-mentioned analyses.

Conclusions

The finding from current meta-analysis suggest that parity may be related to decreased risk of bladder cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-3023-5) contains supplementary material, which is available to authorized users.

Diabetes is an Important Risk Factor for Metastasis in Non- Muscle-Invasive Bladder Cancer

BACKGROUND

Epidemiological evidence indicates that individuals with diabetes mellitus (DM) may have a modestly increased risk of bladder cancer. In the present study, we aimed to show any association between DM and risk of metastasis in patients with non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

We retrospectively analyzed 698 patients between January 2007 and December 2014 who were diagnosed with and underwent transurethral resection of bladder tumors (TUR-BT). Comparisons of means was conducted by independent samples t test, and relations between categorical variables were investigated by non-parametric chi- square test. A p value of 0.05 was accepted as statistically significant in comparisons.

RESULTS

We analyzed 418 patients with non muscle invasive bladder cancer. 123 of whom were diabetic and 295 non-diabetic. In diabetic patients, 13 were N1 stage and 11 M1 stage. When compared with non diabetic patients that was statistically significant (p<0.001). TNM stages were more advanced in diabetic patients (p<0.001), but concurrent CIS (p=0.1) and squamous metaplasia did not significantly differ between diabetic and non-diabetic cases (p=1).

CONCLUSIONS

Diabetic patients with non-muscle-invasive bladder cancer may suffer metastases earlier than expected although they are non invasive. Therefore such patients must be followed-up carefully and early cystectomy decision may be necessary. Further prospective studies with more patients are needed to confirm these findings.

Parity, Age at First Birth, and Risk of Death from Bladder Cancer: A Population-Based Cohort Study in Taiwan

The evidence is limited on the relationship between reproductive factors and bladder cancer (BC). We studied 1,292,462 women who had a first and singleton delivery between 1 January 1978 and 31 December 1987. Each woman in the study cohort was tracked from their first childbirth to 31 December 2009. Vital status of the women was determined by crosswalking records with a computerized mortality database. We used Cox proportional hazard regression models to estimate the hazard ratios (HRs) of death from BC associated with maternal age at first birth and parity. The data showed 63 BC deaths during 34,980,246 person-years of follow-up. BC mortality rate was 0.90 cases for every 100,000 person-years. Compared with women who gave birth under the age of 23, the adjusted HR was 1.24 (95% confidence interval (CI) = 0.66–2.35) for women who gave birth between age 23 and 26 and 2.30 (95% CI = 1.21–4.39) for women who gave birth over the age of 26. Increasing age at first birth (p for trend = 0.01) is associated with a trend in increasing risk of BC mortality. Relative to women who had a single childbirth, the adjusted HRs were 1.17 (95% CI = 0.51–2.69) for women who gave birth to two children, and 1.31 (95% CI = 0.56–3.10) for women with three or more childbirths, respectively. These results were not statistically significant. Study results suggests that giving birth at an early age may confer a protective effect on the risk of death from BC.

Exercise Decreases and Smoking Increases Bladder Cancer Mortality

BACKGROUND

The aim of this study was to investigate modifiable lifestyle factors of smoking, exercise, and obesity with bladder cancer mortality.

PATIENTS AND METHODS

We used mortality-linked data from the National Health Information Survey from 1998 through 2006. The primary outcome was bladder cancer-specific mortality. The primary exposures were self-reported smoking status (never- vs. former vs. current smoker), self-reported exercise (dichotomized as "did no exercise" vs. "light, moderate, or vigorous exercise in ≥ 10-minute bouts"), and body mass index. We utilized multivariable adjusted Cox proportional hazards regression models, with delayed entry to account for age at survey interview.

RESULTS

Complete data were available on 222,163 participants, of whom 96,715 (44%) were men and 146,014 (66%) were non-Hispanic whites, and among whom we identified 83 bladder cancer-specific deaths. In multivariate analyses, individuals who reported any exercise were 47% less likely (adjusted hazard ratio [HR_adj], 0.53; 95% confidence interval [CI], 0.29-0.96; P = .038) to die of bladder cancer than "no exercise". Compared with never-smokers, current (HR_adj, 4.24; 95% CI, 1.89-9.65; P = .001) and former (HR_adj, 2.95; 95% CI, 1.50-5.79; P = .002) smokers were 4 and 3 times more likely, respectively, to die of bladder cancer. There were no significant associations of body mass index with bladder cancer mortality.

CONCLUSION

Exercise decreases and current smoking increases the risk of bladder cancer-specific mortality. These data suggest that exercise and smoking cessation interventions may reduce bladder cancer death.

Nitrate from Drinking Water and Diet and Bladder Cancer Among Postmenopausal Women in Iowa

BACKGROUND

Nitrate is a drinking water contaminant arising from agricultural sources, and it is a precursor in the endogenous formation of N-nitroso compounds (NOC), which are possible bladder carcinogens.

OBJECTIVES

We investigated the ingestion of nitrate and nitrite from drinking water and diet and bladder cancer risk in women.

METHODS

We identified incident bladder cancers among a cohort of 34,708 postmenopausal women in Iowa (1986-2010). Dietary nitrate and nitrite intakes were estimated from a baseline food frequency questionnaire. Drinking water source and duration were assessed in a 1989 follow-up. For women using public water supplies (PWS) > 10 years (n = 15,577), we estimated average nitrate (NO3-N) and total trihalomethane (TTHM) levels and the number of years exceeding one-half the maximum contaminant level (NO3-N: 5 mg/L, TTHM: 40 μg/mL) from historical monitoring data. We computed hazard ratios (HRs) and 95% confidence intervals (CIs), and assessed nitrate interactions with TTHM and with modifiers of NOC formation (smoking, vitamin C).

RESULTS

We identified 258 bladder cancer cases, including 130 among women > 10 years at their PWS. In multivariable-adjusted models, we observed nonsignificant associations among women in the highest versus lowest quartile of average drinking water nitrate concentration (HR = 1.48; 95% CI: 0.92, 2.40; ptrend = 0.11), and we found significant associations among those exposed ≥ 4 years to drinking water with > 5 mg/L NO3-N (HR = 1.62; 95% CI: 1.06, 2.47; ptrend = 0.03) compared with women having 0 years of comparable exposure. TTHM adjustment had little influence on associations, and we observed no modification by vitamin C intake. Relative to a common reference group of never smokers with the lowest nitrate exposures, associations were strongest for current smokers with the highest nitrate exposures (HR = 3.67; 95% CI: 1.43, 9.38 for average water NO3-N and HR = 3.48; 95% CI: 1.20, 10.06 and ≥ 4 years > 5 mg/L, respectively). Dietary nitrate and nitrite intakes were not associated with bladder cancer.

CONCLUSIONS

Long-term ingestion of elevated nitrate in drinking water was associated with an increased risk of bladder cancer among postmenopausal women. Citation: Jones RR, Weyer PJ, DellaValle CT, Inoue-Choi M, Anderson KE, Cantor KP, Krasner S, Robien K, Beane Freeman LE, Silverman DT, Ward MH. 2016. Nitrate from drinking water and diet and bladder cancer among postmenopausal women in Iowa. Environ Health Perspect 124:1751-1758; http://dx.doi.org/10.1289/EHP191.

Coffee and cancer risk: A meta-analysis of prospective observational studies

Meta-analyses on coffee and cancer incidence mainly restricted to limited cancers. We carried out a more comprehensive meta-analysis of cohort studies to explore association between coffee and most cancer types. We conducted comprehensive search and summarized relative risk (RR) and 95% confidence intervals for the highest versus lowest coffee intake and cancer using STATA12. We conducted dose-analysis if result suggested significant association. The publication bias was evaluated with begg's and egger's test. Finally, 105 individual prospective studies were included. Inverse associations were observed on oral, pharyngeal, colon, liver, prostate, endometrial cancer and melanoma, with RR 0.69 (95% CI = 0.48-0.99, I² = 73.4%, P = 0.044), 0.87 (95% CI = 0.78-0.96, I² = 28.4%, P = 0.007), 0.46 (95% CI = 0.37-0.57, I² = 0%, P = 0), 0.89 (95% CI = 0.84-0.93, I² = 30.3%, P = 0.003), 0.73 (95% CI = 0.67-0.80, I²  = 0%, P = 0) and 0.89 (95% CI = 0.80-0.99, I²  = 0%, P = 0.031) respectively. However, the relative risk for lung cancer is 2.18 (95% CI = 1.26-3.75, I²  = 63.3%, P = 0.005). The summary relative risk for increment of 2 cups of coffee were RR = 0.73, 95% CI = 0.67-0.79 for liver cancer, RR = 0.97, 95% CI = 0.96-0.98 for prostate cancer and RR = 0.88, 95% CI = 0.85-0.92 for endometrial cancer. Accordingly, coffee intake was associated with reduced risk of oral, pharynx, liver, colon, prostate, endometrial cancer and melanoma and increased lung cancer risk.

Impact of Glycemic Control and Metformin Use on the Recurrence and Progression of Non-Muscle Invasive Bladder Cancer in Patients with Diabetes Mellitus

The purpose of the present study was to determine the potential relationships of glycemic control and use of metformin with non-muscle invasive bladder cancer characteristics. We reviewed data from 645 patients with non-muscle invasive bladder cancer between January 2004 and May 2015. We analyzed the association of pre and post-operative glycemic control and use of metformin with clinical characteristics of bladder tumors. We also analyzed the association of glycemic control and use of metformin with recurrence-free and progression-free survivals. Diabetes mellitus patients showed decreased recurrence-free survival (hazard ratio 1.42; 95% confidence interval 1.1-1.9; P = 0.021) and progression-free survival (hazard ratio 1.79; 95% confidence interval 1.1-2.8; P = 0.013). Diabetes mellitus patients with a HbA1c ≥ 7.0% demonstrated a higher rate of progression (P = 0.026). Kaplan-Meier analysis showed that progression-free survival rate was associated with poor baseline glycemic control (P = 0.026) and post-operative glycemic control (P = 0.025). However, use of metformin had no impact on the recurrence (P = 1.00) and progression (P = 0.282). In conclusion, poor baseline and post-operative glycemic control was related with shorter progression-free survival of patients with non-muscle invasive bladder cancer. Use of metformin had no impact on the recurrence and progression. Therefore, tight glycemic control and close follow-up for bladder tumor may be beneficial in patients with poor glycemic control.

A clinicoepidemiological study of young age bladder tumors: An eastern Indian scenario

INTRODUCTION

Though, bladder cancer is one of the most common urological malignancies, studies addressing the young age group bladder tumors are rare. Present study was done to determine the clinicoepidemiological aspects of bladder tumor diagnosed in young age patients and to compare these aspects with elderly patients.

PATIENTS AND METHODS

Patients with urinary bladder tumor were selectively divided into two groups; young (<40 years) and elderly (>60 years). Groups were compared on various parameters and statistically analyzed using Fisher's exact two-tailed test.

RESULTS

Smoking, tea and coffee intake and exposure of dye were found significantly associated with development of bladder tumor. Most of the tumors in young age were small, solitary, and papillomatous. Transitional cell carcinoma (TCC) was the most common histological subtype, though most were of low grade and were non-muscle invasive in comparison to the tumors in elderly group.

CONCLUSION

The incidence of bladder cancer is common in younger age group. Active and passive cigarette smoking, tea, coffee intake, and exposure to organic dyes are major risk factor for younger age group bladder tumor in this part of world. TCC is most common histological subtype and most of them are in low grade without muscle invasion.

Quantified relations between exposure to tobacco smoking and bladder cancer risk: a meta-analysis of 89 observational studies

BACKGROUND

Smoking is a major risk factor for bladder cancer (BC). This meta-analysis updates previous reviews on smoking characteristics and BC risk, and provides a more quantitative estimation of the dose-response relationship between smoking characteristics and BC risk.

METHODS

In total, 89 studies comprising data from 57 145 BC cases were included and summary odds ratios (SORs) were calculated. Dose-response meta-analyses modelled relationships between smoking intensity, duration, pack-years and cessation and BC risk. Sources of heterogeneity were explored and sensitivity analyses were conducted to test the robustness of findings.

RESULTS

Current smokers (SOR = 3.14, 95% CI = 2.53-3.75) and former smokers(SOR = 1.83, 95% CI = 1.52-2.14) had an increased risk of BC compared with never smokers. Age at first exposure was negatively associated with BC risk. BC risk increased gradually by smoking duration and a risk plateau at smoking 15 cigarettes a day and 50 pack-years was observed. Smoking cessation is most beneficial from 20 years before diagnosis. The population-attributable risk of BC for smokers has decreased from 50% to 43% in men and from 35% to 26% in women from Europe since estimated in 2000. Results were homogeneous between sources of heterogeneity, except for lower risk estimates found in studies of Asian populations.

CONCLUSIONS

Active smokers are at an increased risk of BC. Dose-response meta-analyses showed a BC risk plateau for smoking intensity and indicate that even after long-term smoking cessation, an elevated risk of bladder cancer remains.

Obesity, Physical Activity and Bladder Cancer

While smoking and exposure to certain chemicals are well-defined risk factors for bladder cancer, there is no consensus as to the roles of modifiable lifestyle factors, notably physical activity, and obesity. We evaluated associations of obesity and physical activity with bladder cancer risk by performing a system-wide search of PubMed for cohort and case-control studies focused on obesity, exercise, and bladder cancer. A total of 31 studies were identified that evaluated the associations of obesity and physical activity with bladder cancer risk: 20 focused on obesity, eight on physical activity, and three on both. There was marked heterogeneity in population composition and outcomes assessment. Fifteen (65%) of the obesity studies used prevalence or incidence as the primary outcome and seven (30%) used bladder cancer mortality. Ten (44%) observed positive and 13 (56%) null associations of obesity with bladder cancer. Three (100%) of three studies also noted strong positive associations of obesity with bladder cancer progression or recurrence. Ten (91%) of the physical activity studies analyzed prevalence or incidence and one (9%) mortality. One (9%) study observed positive, seven (64%) null, and three (27%) negative associations of physical activity with bladder cancer. Study heterogeneity precluded quantitative assessment of outcomes. Obesity is potentially associated with an increased risk of bladder cancer, particularly for progression, recurrence, or death. Further studies of physical activity and bladder cancer are needed to validate these observations and elucidate the associations of exercise with bladder cancer progression and mortality.

Poor Preoperative Glycemic Control Is Associated with Dismal Prognosis after Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma: A Korean Multicenter Study

Purpose

The purpose of this study is to evaluate the effect of diabetes mellitus (DM) and preoperative glycemic control on prognosis in Korean patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNU).

Materials and Methods

A total of 566 patients who underwent RNU at six institutions between 2004 and 2014 were reviewed retrospectively. Kaplan-Meier and Cox regression analyses were performed to assess the association between DM, preoperative glycemic control, and recurrence-free, cancer-specific, and overall survival.

Results

The median follow-up period was 33.8 months (interquartile range, 41.4 months). A total of 135 patients (23.8%) had DM and 67 patients (11.8%) had poor preoperative glycemic control. Patients with poor preoperative glycemic control had significantly shorter median recurrence-free, cancer-specific, and overall survival than patients with good preoperative glycemic control and non-diabetics (all, p=0.001). In multivariable Cox regression analysis, DM with poor preoperative glycemic control showed association with worse recurrence-free survival (hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.31 to 3.90; p=0.003), cancer-specific survival (HR, 2.96; 95% CI, 1.80 to 4.87; p=0.001), and overall survival (HR, 2.13; 95% CI, 1.40 to 3.22; p=0.001).

Conclusion

Diabetic UTUC patients with poor preoperative glycemic control had significantly worse oncologic outcomes than diabetic UTUC patients with good preoperative glycemic control and non-diabetics. Further investigation is needed to elucidate the exact mechanism underlying the impact of glycemic control on UTUC treatment outcome.

Risk of Malignant Neoplasms of Kidney and Bladder in a Cohort Study of the Diabetic Population in Taiwan With Age, Sex, and Geographic Area Stratifications

Diabetes has been reported to increase the risk of malignant neoplasms of kidney and bladder, but the studies' results are still inconclusive. Age, sex, and geographical area-specific incidence and relative risks of above neoplasms are also scarce in the literature. We prospectively investigated the age, sex, geographical area-specific incidence and relative risks of kidney and bladder neoplasms in diabetic population of Taiwan. Diabetic patients (n = 615,532) and age- and sex-matched controls (n = 614,871) were linked to inpatient claims (2000-2008) to identify the admissions for malignant neoplasm of kidney (International Classification of Diagnosis, 9th version, Clinical Modification: 189) and bladder (International Classification of Diagnosis, 9th version, Clinical Modification: 188). The person-year approach with Poisson assumption was used to evaluate the incidence density. We also estimated the age, sex, and geographical area-specific relative risks of above malignancy in relation to diabetes with Cox proportional hazard regression model. The overall incidence density of malignant neoplasm of kidney for diabetic men and women were 3.87 and 4.28 per 10,000 patient-years, respectively; the corresponding figures for malignant neoplasm of bladder were 5.73 and 3.25 per 10,000 patient-years. Compared with the controls, diabetic men were at significantly increased hazards of kidney (covariate adjusted hazard ratio [aHR]: 1.31, 95% confidence interval [CI] 1.18-1.46) and bladder aHR: 1.13, 95% CI 1.04-1.23). Diabetic women, on the contrary, only experienced significantly elevated hazard of kidney neoplasm (aHR: 1.14, 95% CI 1.04-1.26). Diabetic men aged >65 years showed the most significantly increased hazard of developing neoplasm of kidney (aHR: 1.40) and bladder (aHR: 1.13). The most significantly increased hazard of kidney neoplasm was noted for women diabetic patients aged >65 years. There was also a significant interactive effect of geographic area with diabetes on the incidence of kidney and bladder neoplasms in both sexes. Diabetic men >45 years and diabetic women >65 years were found to have significantly increased hazard of malignant neoplasm of kidney, but only diabetic men >65 years were at significantly increased hazard of bladder neoplasm. The significant geographic variations in incidence and relative hazard of kidney and bladder neoplasms warrant further investigations of the underlying reasons.

Obesity and risk of bladder cancer: a dose-response meta-analysis of 15 cohort studies

Background

Epidemiological studies have reported inconsistent association between obesity and risk of bladder cancer, and the dose-response relationship between them has not been clearly defined.

Methods

We carried out a meta-analysis to summarize available evidence from epidemiological studies on this point. Relevant articles were identified by searching the PubMed and Web of Science databases through September 30, 2014. We pooled the relative risks from individual studies using random-effect model, and the dose—response relationship was estimated by using restricted cubic spline model.

Results

Fifteen cohort studies with 38,072 bladder cancer cases among 14,201,500 participants were included. Compared to normal weight, the pooled relative risks and corresponding 95% confidence intervals of bladder cancer were 1.07(1.01-1.14) and 1.10(1.06-1.14) for preobese and obesity, with moderate (I² = 37.6%, P = 0.029) and low (I² = 15.5%, P = 0.241) heterogeneities between studies, respectively. In a dose-response meta-analysis, body mass index (BMI) was associated with bladder cancer risk in a linear fashion (P_{non-linearity} = 0.467) and the risk increased by 4.2% for each 5 kg/m² increase. No significant publication bias was found (P = 0.912 for Begg’s test, P = 0.712 for Egger’s test).

Conclusions

Findings from this dose-response meta-analysis suggest obesity is associated with linear-increased 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.

Anthropometric measures and bladder cancer risk: a prospective study in the EPIC cohort

Anthropometric measures have been related to risk of several cancers. For bladder cancer, however, evidence is sparse. Comparability of existing studies is hampered by use of different obesity-measures, inadequate control for smoking, and few female cases. This study examined associations between height, weight, waist and hip circumference, waist-hip ratio, waist-height ratio, body mass index (BMI), recalled weight at age 20 and bladder cancer, and investigated effect modification by age, tumor aggressiveness and smoking. The study was conducted in the European Prospective Investigation into Cancer and Nutrition cohort, in 390,878 participants. Associations were calculated using Cox Proportional Hazards Models. During follow-up, 1,391 bladder cancers (1,018 male; 373 female) occurred. Height was unrelated to bladder cancer in both genders. We found a small but significant positive association with weight [1.04 (1.01-1.07) per 5 kilo], BMI [1.05 (1.02-1.08) per 2 units], waist circumference [1.04 (1.01-1.08) per 5 cm], waist-hip ratio (1.07 (1.02-1.13) per 0.05 unit] and waist-height ratio [1.07 (1.01-1.13) per 0.05 unit] in men. Stratification by smoking status confined associations in men to former smokers. In never smokers, we found no significant associations, suggesting residual confounding by smoking. Results did not differ with tumor aggressiveness and age. Residual analyses on BMI/waist circumference showed a significantly higher disease risk with BMI in men (p = 0.01), but no association with waist circumference. In conclusion, in this large study, height was unrelated to bladder cancer, whereas overweight was associated with a slightly higher bladder cancer risk in men. This association may, however, be distorted by residual confounding by smoking.

CARING (CAncer Risk and INsulin analoGues): the association of diabetes mellitus and cancer risk with focus on possible determinants - a systematic review and a meta-analysis

Background:

Patients suffering from diabetes mellitus (DM) may experience an increased risk of cancer; however, it is not certain whether this effect is due to diabetes per se.

Objective:

To examine the association between DM and cancers by a systematic review and meta-analysis according to the PRISMA guidelines.

Data Sources:

The systematic literature search includes Medline at PubMed, Embase, Cinahl, Bibliotek.dk, Cochrane library, Web of Science and SveMed+ with the search terms: “Diabetes mellitus”, “Neoplasms”, and “Risk of cancer”.

Study Eligibility Criteria:

The included studies compared the risk of cancer in diabetic patients versus non-diabetic patients. All types of observational study designs were included.

Results:

Diabetes patients were at a substantially increased risk of liver (RR=2.1), and pancreas (RR=2.2) cancer. Modestly elevated significant risks were also found for ovary (RR=1.2), breast (RR=1.1), cervix (RR=1.3), endometrial (RR=1.4), several digestive tract (RR=1.1-1.5), kidney (RR=1.4), and bladder cancer (RR=1.1). The findings were similar for men and women, and unrelated to study design. Meta-regression analyses showed limited effect modification of body mass index, and possible effect modification of age, gender, with some influence of study characteristics (population source, cancer- and diabetes ascertainment).

Limitations:

Publication bias seemed to be present. Only published data were used in the analyses.

Conclusions:

The systematic review and meta-analysis confirm the previous results of increased cancer risk in diabetes and extend this to additional cancer sites. Physicians in contact with patients with diabetes should be aware that diabetes patients are at an increased risk of cancer.

The association between physical activity and bladder cancer: systematic review and meta-analysis

Background:

Physical activity may protect against bladder cancer through several biologic pathways, such as enhanced immune function and decreased chronic inflammation. Physical activity may also indirectly prevent bladder cancer by reducing obesity. A sizeable number of epidemiologic studies have examined the association between physical activity and bladder cancer, but the available evidence has not yet been formally summarised using meta-analysis.

Methods:

We performed a systematic literature review and meta-analysis of English-language studies published from January 1975 through November 2013. We followed the PRISMA guidelines and used a random effects model to estimate the summary risk estimates for the association between physical activity and bladder cancer.

Results:

A total of 15 studies with 5 402 369 subjects and 27 784 bladder cancer cases were included. High vs low levels of physical activity were related to decreased bladder cancer risk (summary relative risk (RR)=0.85, 95% confidence interval (CI)=0.74–0.98; I²=83% P-value for heterogeneity across all studies<0.001). Results were similar for cohort studies (RR=0.89, 95% CI=0.80–1.00; I²=64%) and case–control studies (RR=0.71, 95% CI=0.43–1.16; I²=87% P-value for difference=0.108) and they were comparable for women (RR=0.83, 95% CI=0.73–0.94; I²=0%) and men (RR=0.92, 95% CI=0.82–1.05; I²=67; P-value for difference=0.657). Findings were also comparable for recreational (RR=0.81, 95% CI=0.66–0.99; I²=77%) and occupational physical activity (RR=0.90, 95% CI=0.76–1.0; I²=76% P-value for difference=0.374), and they were largely consistent for moderate (RR=0.85, 95% CI=0.75–0.98; I²=76%) and vigorous activity (RR=0.80, 95% CI=0.64–1.00;I²=87% P-value for difference=0.535).

Conclusions:

Physical activity is associated with decreased risk of bladder cancer. Further studies are required to assess the relations of intensity, frequency, duration, and timing in life of physical activity to bladder cancer risk.

Diabetes mellitus increases the risk of bladder cancer: an updated meta-analysis of observational studies

BACKGROUND

Increasing evidence suggests that diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. We performed an updated meta-analysis to examine the association between DM and risk of bladder cancer.

MATERIALS AND METHODS

We systematically searched the EMBASE and Medline (PubMed) databases (from inception through February 1, 2013) and reviewed the reference lists of relevant publications to search for additional studies. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with random-effects models.

RESULTS

In total, 10 case-control and 14 cohort studies met the inclusion criteria. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer (RR 1.30, 95% CI 1.18-1.43). There was heterogeneity among studies (Pheterogeneity <0.001, I(2)=81.5%). Cohort studies showed a lower risk (RR 1.23, 95% CI 1.09-1.37) than case-control studies (odds ratio 1.46, 95% CI 1.20-1.78). The positive association was significant only in women (RR 1.23, 95% CI 1.02-1.49), but not in men (RR 1.07, 95% CI 0.97-1.18). The combined RRs remained unchanged before and after the studies on type 1 diabetes were excluded from analysis. The association between DM and bladder cancer risk did not differ significantly by methods of DM ascertainment. The combined RRs were 1.17 (95% CI 1.03-1.34), 1.34 (95% CI 1.19-1.51), and 1.57 (95% CI 0.96-2.55), respectively, when restricting the analysis to the studies accounting for body mass index, cigarette smoking, or glucose-lowering drug use.

CONCLUSIONS

This meta-analysis indicates a positive association between DM and risk of bladder cancer. Further studies are warranted to determine whether DM prevention and control can reduce risk of bladder cancer.

Diabetes mellitus increases the risk of bladder cancer: an updated meta-analysis

PURPOSE

Studies have indicated that diabetes mellitus (DM) is a risk factor for bladder cancer; however, not all evidence supports this conclusion. The aim of this meta-analysis was to collate and evaluate all primary observational studies investigating the risk of bladder cancer associated with DM.

METHODS

The PubMed and Google Scholar databases were searched to identify studies that estimated the association of DM and bladder cancer. Summary effect estimates were derived using a random-effects meta-analysis model.

RESULTS

A total of 23 studies (8 case-control studies, 15 cohort studies) including 643,683 DM and 4,819,656 non-DM cases were identified. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer compared with non-DM overall (OR=1.68, 95% CI 1.32-2.13). Analysis of subgroups demonstrated this to be the case in both case-control studies (OR=1.59, 95% CI 1.28-1.97, I2=58%) and cohort studies (RR=1.70, 95% CI 1.23-2.33, I2=96%). There was no gender difference in DM-associated bladder cancer risk. Bladder cancer risk was increased in Asia and the North America region, but not in Europe. Furthermore, DM-associated bladder cancer risk was obviously higher in Asia than North America and Europe or in those with Caucasian ethnicity. With extension of follow-up time, the bladder cancer risk was not increased for the patients with DM.

CONCLUSIONS

This meta-analysis provided further evidence supporting the DM association with a significantly higher risk of bladder cancer obtained from observational studies.

Diabetes mellitus and risk of cancer in Takayama: a population-based prospective cohort study in Japan

Diabetes mellitus (DM) has been reported to be associated with an increased risk of site-specific cancers; however, few studies have assessed associations of DM with both total and site-specific cancers in Japan. We examined the association of a history of DM with cancer incidence in a population-based prospective cohort study in Japan. A total of 14 173 men and 16 547 women over 35 years old, who completed a self-administered baseline questionnaire in 1992, were followed up for cancer incidence from September 1992 to March 2008. At baseline, 6.3% men and 2.9% women had a history of diabetes. A total of 1974 men and 1514 women were identified as newly diagnosed with cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were determined using Cox proportional hazards models. After controlling for potential confounders, men with DM had a modest risk increase of total cancer occurrence compared with those without DM (HR, 1.09; 95% CI, 0.93-1.29). Increased risk of cancer of the liver (HR, 2.18; 95% CI, 1.27-3.74), bile duct (HR, 2.17; 95% CI, 1.01-4.66), and larynx (HR, 3.61; 95% CI, 1.16-11.2) in diabetic men were observed. In women, significant increased risk of total cancer (HR, 1.35; 95% CI, 1.06-1.73) and stomach cancer (HR, 2.15; 95% CI, 1.30-3.54) were observed among diabetic subjects. These data suggest that people with DM may be at increased risk of both total and some site-specific cancers.

Reproductive factors and menopausal hormone therapy and bladder cancer risk in the NIH-AARP Diet and Health Study

The incidence of bladder cancer among women is at least one-third to one-fourth that observed among men in many countries. Even after accounting for known risk factors, the reason for this gender disparity remains unexplained. We conducted a comprehensive evaluation of reproductive factors and exogenous hormone use with a primary focus on menopausal hormone therapy use and risk of bladder cancer in women in the NIH-AARP Diet and Health Study. Reproductive and hormonal factors were ascertained on the baseline questionnaire in 1995-1996 among 201,492 females who were followed until December 31, 2006. During follow-up, 651 cases of bladder cancer were diagnosed. A subset of women provided detailed information on use of MHT in a second questionnaire in 1996-1997. In this analysis, 127,361 females were followed through June 30, 2002 and 198 incident bladder cancer cases were identified. Cox proportional hazard models, adjusted for smoking status, cigarettes per day and body mass index using age as the time metric, were used to obtain hazard ratios (HRs). A reduced risk was observed among parous women (HR=0.76; 95% CI 0.62-0.93) and women who reported late age at menarche (≥15 years) (HR=0.57; 95% CI 0.39-0.84). Women who reported ever using estrogen and progestin therapy had a decreased risk (HR=0.53; 95% CI: 0.34-0.83) compared with women who did not report MHT use. No association was observed for estrogen only users (HR=0.82; 95% CI: 0.58-1.15). Our results suggest a putative role for sex hormones in the etiology of bladder cancer among women.

Risk of bladder cancer in patients with diabetes mellitus: an updated meta-analysis of 36 observational studies

BACKGROUND

Increasing evidence suggests that a history of diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. We performed a systematic review with meta-analysis to explore this relationship.

METHODS

We identified studies by a literature search of Medline (from 1 January 1966) and EMBASE (from 1 January 1974), through 29 February 2012, and by searching the reference lists of pertinent articles. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated with a random-effects model.

RESULTS

A total of 36 studies (9 case-control studies, 19 cohort studies and 8 cohort studies of patients with diabetes) fulfilled the inclusion criteria. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer (the summary RR = 1.35, 95% CI 1.17-1.56, p < 0.001, I2 = 94.7%). In analysis stratified by study design, diabetes was positively associated with risk of bladder cancer in case-control studies (RR = 1.45, 95% CI 1.13-1.86, p = 0.005, I2 = 63.8%) and cohort studies (RR = 1.35, 95% CI 1.12-1.62, p < 0.001, I2 = 94.3%), but not in cohort studies of diabetic patients (RR = 1.25, 95% CI 0.86-1.81, p < 0.001, I2 = 97.4%). The RRs of bladder cancer were 1.38 (1.08-1.78) for men and 1.38 (0.90-2.10) for women with diabetes, respectively. Noteworthy, the relative risk of bladder cancer was negatively correlated with the duration of DM, with the higher risk of bladder cancer found among patients diagnosed within less than 5 years.

CONCLUSIONS

These findings support the hypothesis that men with diabetes have a modestly increased risk of bladder cancer, while women with diabetes were not the case.

Insulin use and smoking jointly increase the risk of bladder cancer mortality in patients with type 2 diabetes

BACKGROUND

Whether insulin use predicts bladder cancer mortality has not been investigated. Furthermore, it is not known whether insulin use and smoking jointly influence the risk.

MATERIALS AND METHODS

A total of 86,939 patients (40,014 men, 46,925 women) with type 2 diabetes mellitus (T2DM) and aged ≥ 25 years in a nationally representative cohort were followed prospectively from 1995 to 2006 for bladder cancer mortality. Cox regression was used considering the following independent variables: age, sex, diabetes duration, body mass index, smoking, insulin use, and area of residence. The models were created for patients aged ≥ 25 and ≥ 65 years, separately; and sensitivity analyses were conducted after excluding (1) patients with duration between onset of diabetes and bladder cancer mortality < 5 years, and (2) patients with diabetes duration at recruitment < 3 years. The joint effect of insulin use and smoking was evaluated.

RESULTS

Patients who died of bladder cancer were characterized by older age, male predominance, longer diabetes duration, smoking, and insulin use. In multivariable Cox models, age, male sex, and insulin use were consistently predictive for bladder cancer mortality in all analyses, whereas the other variables were not. The adjusted hazard ratios for bladder cancer mortality for insulin users vs. nonusers ranged from 1.877 to 2.502 in different models (all P values < .05). Insulin use and smoking jointly increased the adjusted hazard ratio to 3.120 (95% confidence interval, 1.329-7.322).

CONCLUSIONS

Insulin use is significantly predictive for bladder cancer mortality in patients with T2DM. Insulin use and smoking jointly increase the risk.

Diabetes mellitus and risk of bladder cancer: a meta-analysis of cohort studies

OBJECTIVE

Diabetes is associated with increased risk of cancer at several sites, but its association with risk of bladder cancer is still controversial. We examined this association by conducting a systematic review and meta-analysis of cohort studies.

METHODS

Studies were identified by searching PubMed, EMBASE, Scopus, Web of Science, Cochrane register, and Chinese National Knowledge Infrastructure (CNKI) databases through April 29, 2012. Summary relative risks (SRRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

A total of fifteen cohort studies were included in this meta-analysis. Analysis of all studies showed that diabetes was associated with a borderline statistically significant increased risk of bladder cancer (RR 1.11, 95% CI 1.00-1.23; p<0.001 for heterogeneity; I(2) = 84%). When restricting the analysis to studies that had adjusted for cigarette smoking (n = 6) or more than three confounders (n = 7), the RRs were 1.32 (95% CI 1.18-1.49) and 1.20 (95% CI 1.02-1.42), respectively. There was no significant publication bias (p = 0.62 for Egger's regression asymmetry test).

CONCLUSIONS

Our findings support that diabetes was associated with an increased risk of bladder cancer. More future studies are warranted to get a better understanding of the association and to provide convincing evidence for clinical practice in bladder cancer prevention.

Diabetes mellitus and risk of bladder cancer: a meta-analysis of cohort studies

Background

Increasing evidence suggests that diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. To provide a quantitative assessment of this association, we evaluated the relation between DM and incidence and mortality of bladder cancer in an updated meta-analysis of cohort studies.

Methods We identified cohort studies by searching the EMBASE and MEDLINE databases, through 31 March 2012. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with random-effects models.

Results

A total of 29 cohort studies (27 articles) were included in this meta-analysis. DM was associated with an increased incidence of bladder cancer (RR 1.29, 95% CI: 1.08–1.54), with significant evidence of heterogeneity among these studies (p<0.001, I² = 94.9%). In stratified analysis, the RRs of bladder cancer were 1.36 (1.05–1.77) for diabetic men and 1.28 (0.75–2.19) for diabetic women, respectively. DM was also positively associated with bladder cancer mortality (RR 1.33, 95% CI: 1.14–1.55), with evident heterogeneity between studies (p = 0.002, I² = 63.3%). The positive association was observed for both men (RR 1.54, 95% CI: 1.30–1.82) and women (RR 1.50, 95% CI: 1.05–2.14).

Conclusion

These findings suggest that compared to non-diabetic individuals, diabetic individuals have an increased incidence and mortality of bladder cancer.

Diabetes and risk of bladder cancer among postmenopausal women in the Iowa Women's Health Study

PURPOSE

Studies have indicated that diabetes is a risk factor for bladder cancer; however, many failed to adjust for confounding variables. An earlier publication from the Iowa Women's Health Study reported a positive association of baseline diabetes with bladder cancer risk between 1986 and 1998, although the number of cases was small (n = 112). We re-examined the diabetes-bladder cancer risk association by accounting for 12 more years of follow-up and assessed whether the association varied by diabetes duration, body mass index, or waist-to-hip ratio (WHR).

METHODS

Proportional hazards regression was used to estimate the hazard ratio (HR) of bladder cancer (n = 277) in relation to diabetes (before enrollment and during follow-up) and diabetes duration using a time-dependent approach.

RESULTS

In a multivariate time-dependent analysis, the HR for bladder cancer was 1.69 (95 % CI 1.40-2.41) in relation to diabetes among 37,327 postmenopausal women initially free of cancer. There was an interaction between diabetes and WHR (p = 0.01). Bladder cancer HR in diabetic women with WHR > 0.9 was 2.5 times higher than expected. There was no dose-response relation of bladder cancer risk with diabetes duration. Compared to no diabetes, HRs were 1.77, 2.03, and 1.55 for diabetes durations of ≤5, 6-10, and >10 years, respectively.

CONCLUSIONS

We confirmed a positive association between diabetes and bladder cancer risk among white postmenopausal women. We also observed a synergistic interaction between diabetes and high WHR in bladder cancer development that might be explained by increased insulin resistance and inflammation related to abdominal obesity.

Arsenic in water, food and cigarettes: a cancer risk to Pakistani population

Inorganic arsenic (iAs) in drinking water and food items has been associated with lung and bladder cancers in several countries including Pakistan. In present study water, food items were collected from Arsenic (As) endemic areas (southern part of Pakistan) during 2008-2012, to evaluate its impact on the health of local population. Exposure of As was checked by analyzing biological samples (blood and scalp hairs) of male lung and bladder cancer patients (smokers and non-smokers). For comparative purpose the healthy subjects of same age group and residential area as exposed referents (EXR) and from non-contaminated area (Hyderabad, Pakistan) as non-exposed referents (NER) were also selected. As concentration in drinking water, food and biological samples were analyzed using electrothermal atomic absorption spectrometry. The validation of technique was done by the analysis of certified reference material (CRM) of blood and hair samples. The As contents in drinking water and food were found 3-15-folds elevated than permissible limits, where as in biological samples; EXR have 2-3-folds higher than NER and cancer patients have 5-9-folds higher than NER. The significant difference was observed in smokers (P < 0.01). The outcomes of the study revealed that As levels were elevated in blood and scalp hair samples of both types of cancer subjects as compared to referents (P < 0.001). It was observed that the lung cancer patients (LCP) have 20-35% higher levels of As in both biological samples as compared to bladder cancer patients (BCP) due to smoking habit. This study has proved the correlation among As contaminated water, food and cigarette smoking between different types of cancer risks.

Type 2 diabetes mellitus, insulin-use and risk of bladder cancer in a large cohort study

Type 2 diabetes mellitus (T2DM) is associated with increased bladder cancer incidence in some, but not all, studies. Many studies had limited statistical power and few examined risk by insulin-use, duration of diabetes or cancer stage. We examined the association between T2DM and bladder cancer incidence in the Cancer Prevention Study II Nutrition Cohort, a large prospective study with information on insulin-use and duration of diabetes. Diabetes and insulin-use were ascertained from a questionnaire at study enrollment in 1992 or 1993 and updated in 1997 and every 2 years thereafter. During follow-up through 2007, 1,852 cases of incident bladder cancer were identified among 172,791 participants. Multivariable adjusted relative risks (RRs) and 95% confidence intervals (CIs) were estimated using extended Cox regression modeling. There were no associations of T2DM with the risk of bladder cancer overall (RR = 1.01, 95% CI: 0.87-1.17), noninvasive disease (RR = 0.93, 95% CI: 0.76-1.14) or invasive disease (RR = 1.13, 95% CI: 0.91-1.40). Compared to participants without T2DM, risk of invasive bladder cancer was higher among participants who had had T2DM for >15 years (RR = 1.63, 95% CI: 1.09-2.43) and among those using insulin (RR = 1.64, 95% CI: 1.18-2.27). These results do not support an association of T2DM with overall bladder cancer incidence, but do suggest positive associations of long-term T2DM and insulin-use or other factors correlated with severe diabetes, with invasive bladder cancer incidence.

Identifying patients with suspected renal tract cancer in primary care: derivation and validation of an algorithm

BACKGROUND

Earlier diagnosis of renal tract cancer could help improve survival so better tools are needed to help this.

AIM

To derive and validate an algorithm to estimate the absolute risk of renal tract cancer in patients with and without symptoms in primary care.

DESIGN

Cohort study using data from 375 UK QResearch® general practices for development and 189 for validation.

METHOD

Included patients were aged 30-84 years free at baseline of a diagnosis of renal tract cancer (bladder, kidney, ureter, or urethra) and without haematuria, abdominal pain, appetite loss, or weight loss in previous 12 months. The primary outcome was incident diagnosis of renal tract cancer recorded in the next 2 years. Risk factors examined were age, body mass index, smoking, alcohol, deprivation, treated hypertension, renal stones, structural kidney problems, diabetes, previous diagnosis of cancer apart from renal tract cancer, haematuria, abdominal pain, appetite loss, weight loss, diarrhoea, constipation, tiredness, and anaemia. Cox proportional hazards models were used to develop separate risk equations in males and females. Measures of calibration and discrimination assessed performance in the validation cohort.

RESULTS

There were 2878 incident cases of renal tract cancer from 4.1 million person-years in the derivation cohort. Independent predictors in both males and females were age, smoking status, haematuria, abdominal pain, weight loss, and anaemia. A history of prior cancer other than renal tract cancer, and appetite loss were predictors for females only. On validation, the algorithms explained 75% of the variation in females and 76% in males. The receiver operating curve statistics were 0.91 (females) and 0.95 (males). The D statistic was 3.53 (females) and 3.60 (males). The 10% of patients with the highest predicted risks contained 87% of all renal tract cancers diagnosed over the next 2 years.

CONCLUSION

The algorithm has good discrimination and calibration and could potentially be used to identify those at highest risk of renal tract cancer, to facilitate more timely referral and investigation.

Case-control study of male cancer patients exposed to arsenic-contaminated drinking water and tobacco smoke with relation to non-exposed cancer patients

The investigated data indicated that inorganic arsenic in drinking water is associated with increased mortality from different types of cancers. In the present study, biological samples (blood and scalp hair) of male subjects having lung and bladder cancers and non-cancerous subjects belonging to arsenic (As)-exposed area of southern parts of Pakistan were analysed for As contents. The As levels in drinking water of understudy area showed that sections of understudy population are exposed to arsenic concentrations, which was 3-15-fold higher than the permissible level (<10 μg/L). For comparative purposes the biological samples of matched male cancer patient, as referent patients belonging to big city (Hyderabad) who had used municipal treated water with low arsenic levels <10 μg/L, were also collected. The exposed cancer patients have 2-3-fold higher level of As in both biological samples compared to non-exposed case-matched cancerous male subjects. This study is compelling evidence in support of positive associations between arsenic-contaminated water, food and cigarette with different types of risks of cancer.

Impact of diabetes mellitus on recurrence and progression in patients with non-muscle invasive bladder carcinoma: a retrospective cohort study

OBJECTIVE

The aim of the present study was to investigate the relationship between diabetes mellitus (DM) and tumor features in patients with non-muscle invasive bladder cancer (NMIBC).

METHODS

Data from 251 patients who underwent transurethral resection (TUR) for NMIBC from January 2000 to June 2010 were analyzed retrospectively. Patients were divided into two groups: Group I, 159 patients (63%) who did not have DM at the time of surgery; and (ii) Group II, 92 patients (37%) who had DM at the time of surgery. Recurrence- and progression-free survival was assessed in both groups. Preoperative HbA1c levels, as parameter of glycemic control, were determined in Group II patients, with patients divided into two subgroups: (i) HbA1c ≥ 7.0%; and (ii) HbA1c <7.0%. The clinical features of the bladder tumor were compared in these two subgroups.

RESULTS

Compared with Group I, Group II patients were older and had a higher rate of hypertension, recurrence, and progression (P < 0.05). Univariate survival analysis showed that gender, DM, smoking, and serum creatinine were associated with recurrence-free survival (P < 0.05), whereas DM, stage, grade, intravesical instillation, and serum creatinine were associated with progression-free survival. In multivariate survival analysis, DM was found to be an independent factor for recurrence- (hazard ratio [HR] 2.11; 95% confidence interval [CI] 1.4-3.2; P = 0.001) and progression-free survival (HR 9.35; 95% CI 3.1-28.6; P = 0.001). Furthermore, patients with HbA1c ≥ 7.0% exhibited a significantly higher rate of multiplicity (P = 0.001), tumor grade (P = 0.03), and intravesical treatment (P = 0.04).

CONCLUSIONS

In conclusion, DM seems to be an independent predictor of recurrence- and progression-free survival in NMIBC patients. Further prospective studies are needed to establish the prognostic significance of postoperative glycemic control in this patient population.

Association between smoking and risk of bladder cancer among men and women

CONTEXT

Previous studies indicate that the population attributable risk (PAR) of bladder cancer for tobacco smoking is 50% to 65% in men and 20% to 30% in women and that current cigarette smoking triples bladder cancer risk relative to never smoking. During the last 30 years, incidence rates have remained stable in the United States in men (123.8 per 100,000 person-years to 142.2 per 100,000 person-years) and women (32.5 per 100,000 person-years to 33.2 per 100,000 person-years); however, changing smoking prevalence and cigarette composition warrant revisiting risk estimates for smoking and bladder cancer.

OBJECTIVE

To evaluate the association between tobacco smoking and bladder cancer.

DESIGN, SETTING, AND PARTICIPANTS

Men (n = 281,394) and women (n = 186,134) of the National Institutes of Health-AARP (NIH-AARP) Diet and Health Study cohort completed a lifestyle questionnaire and were followed up between October 25, 1995, and December 31, 2006. Previous prospective cohort studies of smoking and incident bladder cancer were identified by systematic review and relative risks were estimated from fixed-effects models with heterogeneity assessed by the I(2) statistic.

MAIN OUTCOME MEASURES

Hazard ratios (HRs), PARs, and number needed to harm (NNH).

RESULTS

During 4,518,941 person-years of follow-up, incident bladder cancer occurred in 3896 men (144.0 per 100,000 person-years) and 627 women (34.5 per 100,000 person-years). Former smokers (119.8 per 100,000 person-years; HR, 2.22; 95% confidence interval [CI], 2.03-2.44; NNH, 1250) and current smokers (177.3 per 100,000 person-years; HR, 4.06; 95% CI, 3.66-4.50; NNH, 727) had higher risks of bladder cancer than never smokers (39.8 per 100,000 person-years). In contrast, the summary risk estimate for current smoking in 7 previous studies (initiated between 1963 and 1987) was 2.94 (95% CI, 2.45-3.54; I(2) = 0.0%). The PAR for ever smoking in our study was 0.50 (95% CI, 0.45-0.54) in men and 0.52 (95% CI, 0.45-0.59) in women.

CONCLUSION

Compared with a pooled estimate of US data from cohorts initiated between 1963 and 1987, relative risks for smoking in the more recent NIH-AARP Diet and Health Study cohort were higher, with PARs for women comparable with those for men.

Diabetes and risk of bladder cancer: a study using the National Health Insurance database in Taiwan

AIMS/HYPOTHESIS

Studies on the link between diabetes and bladder cancer in Asians are rare. We investigated the association between diabetes and incidence of bladder cancer by using a large national insurance database.

METHODS

A random sample of 1,000,000 individuals covered by the National Health Insurance was recruited. A total of 495,199 men and 503,748 women for all ages and 187,609 men and 189,762 women ≥40 years old and without bladder cancer at recruitment were followed from 2003 to 2005. Cox regression evaluated the adjusted relative risk for all ages and for age ≥40 years old.

RESULTS

The results were similar for all ages and for age ≥40 years. In Cox models, patients with diabetes consistently showed a significantly higher relative risk ranging from 1.36 to 1.51 after adjustment for age, sex and other potential confounders. Age, male sex, nephropathy, urinary tract diseases (infection and stone) and statin use were associated with bladder cancer, but occupation, hypertension, stroke, ischaemic heart disease, peripheral arterial disease, eye disease, dyslipidaemia and medications (oral glucose-lowering agents including sulfonylurea, metformin, acarbose and thiazolidinediones, insulin, fibrates, ACE inhibitors/angiotensin receptor blockers and calcium channel blockers) were not. Chronic obstructive pulmonary disease and living in regions other than Metropolitan Taipei were associated with lower risk.

CONCLUSIONS

Patients with diabetes have a higher risk of bladder cancer. The association with urinary tract diseases suggests a complex scenario in the link between bladder cancer and diabetes at different disease stages.