Relative importance of risk factors in bladder carcinogenesis: some new results about Mediterranean habits

Is there a promoting role for artificial sweeteners in the evolution of bladder cancer? A meta-analysis of current literature

INTRODUCTION

Urinary bladder cancer is a frequent neoplasia in the urogenital system. Ageing and smoking are the two main risk factors, however, some chemical agents such as artificial sweeteners could act as initiators or promoters.

EVIDENCE ACQUISITION

After identifying trends in scientific literature, we conducted a wide search in PubMed database and a meta-analysis was performed on extracted data to determine the role of artificial sweeteners in the development of urinary bladder cancer.

EVIDENCE SYNTHESIS

Twenty-one full reports were enrolled from screening of PubMed database into final analysis involving 116,568 subjects in comparisons. Overall, 13,682 and 102,886 cases were identified for bladder cancer patients and healthy controls, respectively. Among artificial sweetener users, 12.5% was the incidence of bladder cancer. In the control group, 11.2% of cases suffered from urothelial carcinoma of the bladder. About 40.7% of the patients suffering from urinary neoplasms and 37.8% of the healthy cases were artificial sweetener users, respectively. There were only minor differences in overall descriptive data. The incidence of urinary bladder cancer among artificial sweetener users and control cases showed no risk difference (RD: 0.00, CI: -0.06 to 0.06). The frequency of artificial sweetener use among patients suffering from urinary bladder neoplasms and healthy subjects was compared which showed equal occurrences (OR: 0.96, CI: 0.79 to 1.17).

CONCLUSIONS

According to our results, the carcinogenic risk of artificial sweeteners is not proven. Saccharin should not be kept as a promoter in urothelial malignant transformation.

Non-sugar sweeteners and cancer: Toxicological and epidemiological evidence

Several toxicological and epidemiological studies were published during the last five decades on non-sugar sweeteners (NSS) and cancer. Despite the large amount of research, the issue still continues to be of interest. In this review, we provided a comprehensive quantitative review of the toxicological and epidemiological evidence on the possible relation between NSS and cancer. The toxicological section includes the evaluation of genotoxicity and carcinogenicity data for acesulfame K, advantame, aspartame, cyclamates, saccharin, steviol glycosides and sucralose. The epidemiological section includes the results of a systematic search of cohort and case-control studies. The majority of the 22 cohort studies and 46 case-control studies showed no associations. Some risks for bladder, pancreas and hematopoietic cancers found in a few studies were not confirmed in other studies. Based on the review of both the experimental data on genotoxicity or carcinogenicity of the specific NSS evaluated, and the epidemiological studies it can be concluded that there is no evidence of cancer risk associated to NSS consumption.

The relationship between the use of artificial sweeteners and cancer: A meta-analysis of case-control studies

Although there are reports that artificial sweeteners (AS) are safe, the relationship between artificial sweeteners and cancer remains controversial. The purpose of the study is to evaluate whether the consumption of artificial sweeteners is associated with the risk of cancers. We conducted a comprehensive search of multiple databases, including MEDLINE, EMBASE, Web of Science, and Cochrane Library. We found all the literature that studied the relationship between artificial sweeteners and cancer. Ten case-control studies were included in the meta-analysis. Our findings indicated that the consumption of artificial sweeteners was not associated with an increase in cancer when all types of cancers are analyzed comprehensively (OR 0.91, 95% CI 0.75-1.11). Interestingly, the use of artificial sweeteners is inversely related to urinary system cancer risk when analyzing women individually (OR 0.76, 95% CI 0.60-0.97). Our meta-analysis found that these is no correlation between artificial sweeteners and occurrence of cancer except urinary system cancer in women. Considering some limitations found in this study, additional data from large clinical trials are needed.

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

BACKGROUND

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

MATERIALS AND METHODS

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

STUDY DESIGN

observational cohorts or case-control.

RESULTS

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

CONCLUSION

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

Association between intake of non-sugar sweeteners and health outcomes: systematic review and meta-analyses of randomised and non-randomised controlled trials and observational studies

OBJECTIVE

To assess the association between intake of non-sugar sweeteners (NSS) and important health outcomes in generally healthy or overweight/obese adults and children.

DESIGN

Systematic review following standard Cochrane review methodology.

DATA SOURCES

Medline (Ovid), Embase, Cochrane CENTRAL, WHO International Clinical Trials Registry Platform, Clinicaltrials.gov, and reference lists of relevant publications.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies including generally healthy adults or children with or without overweight or obesity were eligible. Included study designs allowed for a direct comparison of no intake or lower intake of NSS with higher NSS intake. NSSs had to be clearly named, the dose had to be within the acceptable daily intake, and the intervention duration had to be at least seven days.

MAIN OUTCOME MEASURES

Body weight or body mass index, glycaemic control, oral health, eating behaviour, preference for sweet taste, cancer, cardiovascular disease, kidney disease, mood, behaviour, neurocognition, and adverse effects.

RESULTS

The search resulted in 13 941 unique records. Of 56 individual studies that provided data for this review, 35 were observational studies. In adults, evidence of very low and low certainty from a limited number of small studies indicated a small beneficial effect of NSSs on body mass index (mean difference -0.6, 95% confidence interval -1.19 to -0.01; two studies, n=174) and fasting blood glucose (-0.16 mmol/L, -0.26 to -0.06; two, n=52). Lower doses of NSSs were associated with lower weight gain (-0.09 kg, -0.13 to -0.05; one, n=17 934) compared with higher doses of NSSs (very low certainty of evidence). For all other outcomes, no differences were detected between the use and non-use of NSSs, or between different doses of NSSs. No evidence of any effect of NSSs was seen on overweight or obese adults or children actively trying to lose weight (very low to moderate certainty). In children, a smaller increase in body mass index z score was observed with NSS intake compared with sugar intake (-0.15, -0.17 to -0.12; two, n=528, moderate certainty of evidence), but no significant differences were observed in body weight (-0.60 kg, -1.33 to 0.14; two, n=467, low certainty of evidence), or between different doses of NSSs (very low to moderate certainty).

CONCLUSIONS

Most health outcomes did not seem to have differences between the NSS exposed and unexposed groups. Of the few studies identified for each outcome, most had few participants, were of short duration, and their methodological and reporting quality was limited; therefore, confidence in the reported results is limited. Future studies should assess the effects of NSSs with an appropriate intervention duration. Detailed descriptions of interventions, comparators, and outcomes should be included in all reports.

SYSTEMATIC REVIEW REGISTRATION

Prospero CRD42017047668.

Health outcomes of non-nutritive sweeteners: analysis of the research landscape

BACKGROUND

Food products containing non-nutritive sweeteners (NNSs) instead of sugar have become increasingly popular in the last decades. Their appeal is obviously related to their calorie-free sweet taste. However, with the dramatic increase in their consumption, it is reasonable and timely to evaluate their potential health benefits and, more importantly, potential adverse effects. The main aim of this scoping review was to map the evidence about health outcomes possibly associated with regular NNS consumption by examining the extent, range, and nature of research activity in this area.

METHODS

We systematically searched Ovid MEDLINE, EMBASE and the Cochrane CENTRAL databases for studies on NNSs (artificial sweeteners or natural, non-caloric sweeteners, either used individually or in combination) using text terms with appropriate truncation and relevant indexing terms. All human studies investigating any health outcomes of a NNS intervention or exposure were eligible for inclusion. No studies were excluded based on language, study design or methodological quality. Data for each health outcome were summarized in tabular form and were discussed narratively.

RESULTS

Finally, we included 372 studies in our scoping review, comprising 15 systematic reviews, 155 randomized controlled trials (RCTs), 23 non-randomized controlled trials, 57 cohort studies, 52 case-control studies, 28 cross sectional studies and 42 case series/case reports. In healthy subjects, appetite and short term food intake, risk of cancer, risk of diabetes, risk of dental caries, weight gain and risk of obesity are the most investigated health outcomes. Overall there is no conclusive evidence for beneficial and harmful effects on those outcomes. Numerous health outcomes including headaches, depression, behavioral and cognitive effects, neurological effects, risk of preterm delivery, cardiovascular effects or risk of chronic kidney disease were investigated in fewer studies and further research is needed. In subjects with diabetes and hypertension, the evidence regarding health outcomes of NNS use is also inconsistent.

CONCLUSIONS

This scoping review identifies the needs for future research to address the numerous evidence gaps related to health effects of NNSs use.It also specifies the research questions and areas where a systematic review with meta-analyses is required for the proper evaluation of health outcomes associated to regular NNSs consumption.

Environmental procarcinogen hypothesis of bladder cancer in humans: Dapsone hydroxylation as a susceptibility risk factor for aggressive bladder cancer

The dapsone recovery ratio (DPRR), which is determined after single oral dose administration of dapsone by measuring the parent drug and hydroxylated metabolite, provides an in vivo measure of the efficiency of the drug metabolizing enzymes responsible for this metabolic route, putatively CYP3A4. This affords the potential to evaluate the hypothesis that this drug metabolizing enzyme system is involved in the pathogenesis of human bladder cancer. The present study is a matched case-control comparison of DPRR in patients with nonaggressive bladder cancer (grades I and II or Ta, T1 and T2, n = 43), patients with aggressive bladder cancer without invasion (grade III or Ta, T1 and T2, n = 32), patients with aggressive bladder cancer and invasion (grade III or T3 and T4, n = 32), and age- and gender-matched subjects with no urologic tumor on cystoscopy from an urban U.K. community (n = 85). Demographic variables associated with aggressive bladder cancer (Gill or T3, T4, Tis) included pack-years of smoking, alcohol intake, and occupational exposure; for nonaggressive bladder cancer variables included smoking and occupational exposure. DPRR exhibited an unimodal distribution in all subjects: activity was significantly reduced in both noninvasive and invasive aggressive bladder cancer, and was a significant risk factor for cancer after adjustment for other significant risk factors. Combining the two aggressive groups, the lowest tertile of DPRR activity was associated with a sixfold increase in risk (p < 0.02) compared with the upper tertile. We conclude that a low dapsone recovery ratio is an independent risk factor for aggressive bladder cancer irrespective of its stage of invasion and suggest that the enzymes involved in its metabolism are detoxifying enzymes for unknown environmental factors to which an urban community is exposed.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Dietary intake of vegetables and fruits and the modification effects of GSTM1 and NAT2 genotypes on bladder cancer risk

We analyzed the association between intakes of vegetables and fruits as defined by the U.S. Department of Agriculture pyramid food groups and bladder cancer risk using data collected in a large case-control study. The study included 884 histologically confirmed bladder cancer cases and 878 healthy controls matched to cases by age (+/-5 years), gender, and ethnicity. Significant inverse associations were observed for intakes of total vegetables, cruciferous vegetables, orange vegetables, dark green vegetables, and bladder cancer risk. Compared with those in the lowest quartile of total vegetable intake, the odds ratios for the 2nd, 3rd, and 4th quartiles of total vegetable intake were 0.84 [95% confidence interval (95% CI), 0.64-1.10], 0.71 (95% CI, 0.54-0.95), and 0.67 (95% CI, 0.50-0.90), respectively (P for trend = 0.004). Compared with those in the lowest quartile, those in the highest quartile of cruciferous vegetable intake had an odds ratio of 0.69 (95% CI, 0.52-0.92; P for trend = 0.001) and those in the highest quartile of orange vegetable intake had an odds ratio of 0.68 (95% CI, 0.52-0.91; P for trend = 0.006). Furthermore, the protective effect of cruciferous vegetables was more evident in subjects carrying GSTM1-null (odds ratio, 0.43; 95% CI, 0.25-0.73 for the 4th quartile of intake) and NAT2-slow genotypes (odds ratio, 0.56; 95% CI, 0.33-0.97 for the 4th quartile of intake). No association was observed for intakes of total fruits or citrus fruits. Our data strongly support that high vegetable consumption, especially cruciferous vegetable intake, may protect against bladder cancer and that genetic variants of GSTM1 and NAT2 may modify the association.

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

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

Nutrition, total fluid and bladder cancer

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

Coffee and alcohol consumption and bladder cancer

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

Coffee, green tea, and caffeine consumption and subsequent risk of bladder cancer in relation to smoking status: a prospective study in Japan

Coffee and caffeine consumption are thought to increase the risk of bladder cancer. However, few studies have stratified this risk by smoking status, which is a potential confounder. Here, we investigated the association between coffee, green tea (another major source of caffeine), and caffeine, and bladder cancer incidence in relation to smoking status. We conducted a population-based prospective study in a cohort of Japanese, comprising a total of 49 566 men and 54 874 women aged 40–69 years who reported their coffee and green tea consumption at baseline. During follow-up from 1990 through 2005, 164 men and 42 women were newly diagnosed with bladder cancer. Cigarette smoking was associated with an increased risk of bladder cancer, with a strong dose–response relationship. Coffee was positively associated with bladder cancer risk in men, without statistical significance. When stratified by smoking status, coffee and caffeine consumption were associated with an increased risk of bladder cancer in never- or former-smoking men, with hazard ratios (95% confidence interval) in the highest categories of coffee (one or more cups per day) and caffeine consumption compared with the lowest of 2.24 (95% CI = 1.21–4.16) and 2.05 (95% CI = 1.15–3.66), respectively. In conclusion, cigarette smoking was confirmed as a risk factor for bladder cancer. Coffee and caffeine may be associated with an increased bladder cancer risk in never or former smokers among Japanese men.

Urinary bladder cancer risk factors in men: a Spanish case–control study

The rising incidence of urinary bladder cancer is alarming and potential relationships with different risk factors have been postulated. The purpose of this study was to examine the possible relationship between different environmental risk factors and urinary bladder cancer. All men with urinary bladder cancer who were admitted to the Department of Urology of Reina Sofia University Hospital of Cordoba, Spain over 1 year were included in our study. Men were administered an interview questionnaire, which included data on history of known urinary bladder cancer risk factors. Comparisons between men with urinary bladder cancer (cases) and those with nonmalignant urological disease (controls) were made. The study included 74 cases and 89 controls. The variables associated with malignant lesions on univariate analysis were age, smoking and drinking alcohol. Meanwhile, fish, poultry and beef consumption were proved to be protective factors. The risk factors identified by the logistic regression analysis were age, smoking and fluid intake. The independent protective factors on the multivariate analysis were fish and poultry consumptions. Smoking was found to be the principal independent risk factors for urinary bladder cancer. Our results call for further investigation of urinary bladder cancer risk factors; future studies should preferably be performed on large prospective cohorts, to increase their validity.

Evaluation of the effect of dietary vegetable consumption on reducing risk of transitional cell carcinoma of the urinary bladder in Scottish Terriers

OBJECTIVE

To evaluate the effects of vegetable consumption and vitamin supplementation on the risk of developing transitional cell carcinoma (TCC) of the urinary bladder in Scottish Terriers.

DESIGN

Case-control study.

ANIMALS

92 adult Scottish Terriers with TCC (cases) and 83 Scottish Terriers with other conditions (controls).

PROCEDURE

Owners of dogs with TCC completed a questionnaire regarding their dogs' diet and intake of vitamin supplements in the year prior to diagnosis of TCC; owners of control dogs completed the questionnaire for a comparable time period. The risk (odds ratio [OR]) of developing TCC associated with diet and vitamin supplementation was determined by use of logistic regression.

RESULTS

After adjustment for age, weight, neuter status, and coat color, there was an inverse association between consumption of vegetables at least 3 times/wk (OR, 0.30; 95% confidence interval [CI], 0.15 to 0.62) and risk of developing TCC. For individual vegetable types, the risk of developing TCC was inversely associated with consumption of green leafy vegetables (OR, 0.12; 95% CI, 0.01 to 0.97) and yellow-orange vegetables (OR, 0.31; 95% CI, 0.14 to 0.70). Consumption of cruciferous vegetables was not significantly associated with a similar reduction in risk of developing TCC (OR, 0.22; CI, 0.04 to 1.11). The power of the study to detect a 50% reduction in TCC risk associated with daily vitamin supplementation was considered low (25%).

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that consumption of certain vegetables may prevent or slow the development of TCC in Scottish Terriers.

Diet and Bladder Cancer: A Case–Control Study

To investigate possible relationships between diet and risk for bladder cancer in Serbia, the hospital-based case-control study was carried out. This study included 130 newly diagnosed bladder cancer patients and the same number of controls matched by sex, age (%+/-%2 years) and type of residence (rural or urban). Dietary information was obtained by using a food frequency questionnaire. Initial case-control comparisons were based on tertiles of average daily intake of control group. The odds ratios (ORs) were computed for each tertile, with the lowest tertile defined as the referent category. All variables (food items) significantly related to bladder cancer were included in multivariable logistic regression analysis. According to this analysis, risk factors for bladder cancer appeared to be consumption of liver (OR=6.60, 95%CI=1.89-23.03), eggs (OR=3.12, 95%CI=1.10-8.80), pork (OR=2.99, 95%CI=1.16-7.72), and pickled vegetable (OR=3.25, 95%CI=1.36-7.71). A protective effect was found for dietary intake of kale (OR=0.21, 95%CI=0.06-0.73), cereals (OR=0.19, 95%CI=0.06-0.62), tangerines (OR=0.21, 95%CI=0.07-0.68), cabbage (OR=0.27, 95% CI=0.11-0.68), and carrots (OR=0.15, 95%CI=0.05-0.41). The study indicated a potentially important role for dietary fat and pickled vegetables in bladder carcinogenesis. An inverse association was recorded between consumption of fruits, vegetables and cereals, and the development of bladder cancer.

Diet in bladder cancer ethiopathogenesis

The aim of this paper is to show influence of different foods on bladder cancer appearance, as well as possible consequent ways of prevention. Consumption of food rich in animal fat and cholesterol, fried foods, especially several times used cookin oil for frying, processed meat with additives (nitrates, nitrites, azo-colourrs) can influence bladder cancer occurrence. Regularly, continuous consumption of fermented milk products, which contains come types of milky - acids bacterias, is considered as protective factor in developing bladder cancer. Reports that fruit and vegetable are protective food items are pretty consistent. Data about mineral intake and bladder cancer are obscure.

Superficial papillary urothelial carcinomas in young and elderly patients: a comparative study

OBJECTIVE

To compare the clinicopathological and immunohistochemical findings of superficial papillary transitional cell carcinomas in "young" and "elderly" patients, as the natural history and prognosis of bladder tumours in young patients remains a matter of debate.

PATIENTS AND METHODS

Tumours from 50 patients with superficial urothelial tumours of the bladder diagnosed before 45 years old ("young" group, follow-up 25-119 months) were compared with 90 similar tumours developed in patients aged >55 years ("elderly", follow-up 24-102 months). All the patients had a transurethral resection with curative intent, and none had received any therapy before surgery. After surgery only patients diagnosed with pT1 tumours were treated by intravesical bacille Calmette-Guérin (BCG) instillations; all received intravesical BCG if there was a recurrence. The clinicopathological variables, recurrence and disease-free interval to recurrence were assessed. Proliferative activity (MIB-1) and expression of cell-cycle regulation proteins cyclin D1, p53 and p27(kip1) were detected by immunohistochemistry in the tumours of both groups. RESULTS There were statistically significant differences in tumour grade, stage and occurrence between the "young" and "elderly" groups. The 'young' group had a longer disease-free interval to recurrence. Among the immunohistochemical markers analysed, only MIB-1 and cyclin D1 were associated with an increased risk of recurrence in the "young" group (P < 0.04 and <0.01, respectively) in a univariate analysis. CONCLUSIONS Superficial papillary urothelial tumours of the bladder in "young" patients had a better prognosis than those in the "elderly" group, showing a lower grade and stage at diagnosis, and a lower recurrence rate. Proliferative activity and cyclin D1 expression levels were of prognostic significance for the risk of recurrence in these patients.

Coffee and tea consumption and cancers of the bladder, colon and rectum

Coffee has been observed to be associated weakly or not at all with bladder cancer risk, inversely with colon cancer risk, and inconsistently with rectal cancer risk. The association between these cancers and consumption of coffee and tea was examined in a single case-control study conducted in Ontario, Canada from 1992 to 1994. A questionnaire was filled out by 927 bladder cancer cases, 991 colon cancer cases, 875 rectal cancer cases, and 2118 population controls. Although bladder cancer risk was not associated with coffee or tea, risk estimates associated with coffee among subjects who had never smoked were non-significantly increased. Colon cancer risk was inversely associated with coffee. Relative to those drinking less than 1 cup of coffee per day, the odds ratios (OR) for those drinking 1-2 cups was 0.9 (95% CI 0.8-1.1), for those drinking 3-4 cups was 0.8 (95% CI 0.7-1.0), and for those drinking 5 or more cups was 0.7 (95% CI 0.5-0.9); these ORs decreased linearly (P = 0.008). The reduced risk estimates were more pronounced with cancer of the proximal colon than the distal colon. Rectal cancer risk was not associated with either coffee or tea. Coffee consumption was observed to have a different relationship for each of the cancer sites and tea consumption was not related to any cancer site.

Foods and nutrients in relation to bladder cancer risk: a case-control study in Aichi Prefecture, Central Japan

To elucidate the role of diet in the etiology of bladder cancer, we conducted a case-control study from 1996 to 1999 in Aichi Prefecture, Central Japan. Cases were patients newly diagnosed with bladder cancer, and one hospital control was selected for each case, matching gender, age, and hospital. A well-validated food frequency questionnaire was adopted to estimate intakes of nutrients and food groups. Odds ratios (ORs) adjusted for smoking and occupational history were computed using conditional logistic models. The analyses based on 297 cases and 295 controls revealed the following. 1) The more the intake of milk and dairy products, the lower the OR; the ORs across quartiles in all subjects were 1.02, 0.73, and 0.52. Fruit intake was negatively associated with the risk, particularly in men (ORs across quartiles = 0.76, 0.77, and 0.52). Green-yellow vegetables were associated with a decreased risk in the highest quartile of consumption in men (OR = 0.57). 2) Dietary intakes of retinol and saturated fatty acids were related to a reduced risk in all subjects (ORs across quartiles = 0.75, 0.54, and 0.66 and 0.55, 0.54, and 0.60, respectively). Monounsaturated fatty acids had an inverse association with bladder cancer risk in men.

Are coffee and tea consumption associated with urinary tract cancer risk? A systematic review and meta-analysis

BACKGROUND

Narrative reviews have concluded that there is a small association between coffee consumption and an increased risk of urinary tract cancer, possibly due to confounding by smoking. No association for tea consumption has been indicated. This systematic review attempts to summarize and quantify these associations both unadjusted and adjusted for age, smoking and sex.

METHOD

Thirty-four case-control and three follow-up studies were included in this systematic review. Summary odds ratios (OR) were calculated by meta-regression analyses.

RESULTS

The unadjusted summary OR indicated a small increased risk of urinary tract cancer for current coffee consumers versus non-drinkers. The adjusted summary OR were: 1.26 (95% CI : 1.09-1.46) for studies with only men, 1.08 (95% CI : 0.79-1.46) for studies with only women and 1.18 (95% CI : 1.01-1.38) for studies with men and women combined. Neither unadjusted nor adjusted summary OR provided evidence for a positive association between tea consumption and urinary tract cancer. Even though studies differed in methodology, the results were rather consistent. We did not perform dose-response analyses for coffee and tea consumption due to sparse data.

CONCLUSIONS

In accordance with earlier reviews, we found that coffee consumption increases the risk of urinary tract cancer by approximately 20%. The consumption of tea seems not to be related to an increased risk of urinary tract cancer.

Coffee and cancer: a review of epidemiological studies, 1990-1999

Epidemiological studies on the relation between coffee consumption and cancer risk have been mainly focused on cancers of the urinary bladder, pancreas and colorectum. The relation between coffee and bladder cancer is controversial, despite a large number of studies published over the last three decades. In most studies, the risk tends to be higher in coffee drinkers than in those who do not drink coffee, but the excess risk is generally moderate and is neither dose- nor duration-related. Thus, a strong association between coffee drinking and bladder cancer can be excluded, although it is still unclear whether the weak association is causal or nonspecific and due to some bias or confounding. For pancreatic cancer, a possible association with coffee consumption has been postulated in a large case-control study published in 1981; since then, however, most studies have shown no substantial association, and overall evidence suggests that coffee is not materially related to pancreatic cancer risk. Overall evidence on the coffee-colorectal cancer relation suggests an inverse association, since most case-control studies found odds ratios below unity, particularly for colon cancer. The pattern of risk is less clear for cohort studies. A plausible biological explanation has been given in terms of coffee-related reduction of bile acids and neutral sterol secretion in the colon. For other cancer sites, including oral cavity, oesophagus, stomach, liver, breast, ovary, kidney and lymphoid neoplasms, the relation of coffee drinking with cancer risk has been less extensively investigated, but the evidence is largely reassuring.

Bladder-cancer incidence in relation to vegetable and fruit consumption: a prospective study of atomic-bomb survivors

We examined the relation between consumption of 22 dietary items and subsequent bladder-cancer incidence in a cohort of atomic-bomb survivors in Japan. Subjects were 38,540 people (14,873 men and 23,667 women) who responded to a mail survey carried out between 1979 and 1981 and who had no known cancer diagnosed before the start of follow-up (1 January 1980 for men, 1 February 1981 for women). Consumption frequencies for 22 dietary items were ascertained with pre-coded answers. As of the end of 1993, there were 114 (83 men and 31 women) incident cases of bladder cancer among 450,326 person-years at risk. Statistical analysis was done using Poisson regression for grouped survival data Consumption of green-yellow vegetables and fruit were protectively associated with risk. Adjusted for gender, age, radiation exposure, smoking status, educational level, body-mass index and calendar time, the relative risk (RR) for those consuming green-yellow vegetables 2-4 times per week and almost everyday was 0.62 [95% confidence interval (CI) 0.39-0.98] and 0.54 (95% CI 0.30-0.94) respectively, as compared with those consuming once per week or less. The corresponding RR for fruit consumption was 0.50 (0.30-0.81) and 0.62 (0.39-0.99) respectively. Chicken consumption was unexpectedly associated with decreased risk, but additional adjustment for consumption did not change the relation of green-yellow vegetables or of fruit to risk. The consumption of the other dietary items, including meat and green tea, was not related to risk. The findings add to evidence that high consumption of vegetables and fruit are protective against bladder cancer.

Non-occupational risk factors for cancer of the lower urinary tract in Germany

In a hospital-based case-control study conducted between 1989 and 1992 in Hessen (West Germany) 300 cases (239 male and 61 female) of histologically confirmed cancer of the lower urinary tract (LUT) were individually matched to controls from the same hospitals with respect to sex, age and area of residence. Smoking of cigarettes was associated with an elevated risk of 2.80 in males (95% confidence interval (CI): 1.65-4.76) and 5.33 (95% CI: 1.55-18.33) in females, as compared with nonsmokers. Variables like daily amount of smoked cigarettes, duration of smoking, age at beginning of cigarette smoking and time since smoking cessation showed a clear dose- and time-response relationship in males, but not in females. Elevated risks were observed for higher consumption of coffee, beer and wine, but - especially for the consumption of coffee were drastically reduced after adjustment for smoking. A weak association was found between the daily fluid intake and bladder cancer in males. Among females a significantly decreased odds ratio (OR) of 0.34 (95% CI: 0.11-0.99) was found for a daily fluid intake of more than two liters. Protective effects and risk reductions of approximately 50% were found for the regular intake of raw carrots, kale, salads and fruits. The findings of this investigation support an association between lifestyle factors and cancer of the lower urinary tract.

Fruit and vegetable intake and incidence of bladder cancer in a male prospective cohort

BACKGROUND

Previous epidemiologic studies of fruit and vegetable intake and bladder cancer risk have yielded inconsistent results, especially with regard to the types of fruits and vegetables consumed. We examined total fruit and vegetable intake, as well as intakes of subtypes of fruits and vegetables, in relation to bladder cancer risk in a large male prospective cohort study.

METHODS

Two hundred fifty-two cases of incident bladder cancer were diagnosed from 1986 through January 31, 1996, among 47,909 men enrolled in the Health Professionals Follow-up Study. Each participant in this cohort completed a 131-item food-frequency questionnaire in 1986 and subsequently in 1990 and 1994. We used logistic regression analyses to examine fruit and vegetable intake in relation to bladder cancer risk, after adjusting for age, history of cigarette smoking, current smoking status, geographic region, total fluid intake, and caloric intake.

RESULTS

We observed a weak, inverse association that was not statistically significant between total fruit and vegetable intake and bladder cancer risk. Intake of cruciferous vegetables was inversely associated with risk (relative risk = 0.49; 95% confidence interval = 0.32-0.75, for the highest category of cruciferous vegetable intake compared with the lowest), but intakes of yellow or green leafy vegetables or carotenoid-rich vegetables were not associated with risk. Individual cruciferous vegetables, except for coleslaw, were all inversely related to bladder cancer risk, but only the associations for broccoli and cabbage were statistically significant.

CONCLUSIONS

Data from this study indicate that high cruciferous vegetable consumption may reduce bladder cancer risk, but other vegetables and fruits may not confer appreciable benefits against this cancer.

Fluid intake and the incidence of bladder cancer among middle-aged men and women in a three-county area of western Washington

This population-based case-control study reports on the relationship between fluid intake and the incidence of bladder cancer among 262 bladder cancer cases from Western Washington and 405 controls identified through random-digit dialing Cases were identified from the Surveillance. Epidemiology, and End Results (SEER) registry and were diagnosed between January 1987 and June 1990. All eligible subjects were Caucasian 45- to 65-year-old residents of King, Pierce, or Snohomish counties and completed a structured telephone interview. Analyses were conducted by logistic regression with adjustment for age, county, and smoking (current, former, never). Among women there was a positive association between total fluid intake and the incidence of bladder cancer [p (trend = 0.02] and a moderate positive association between the use of decaffeinated coffee and the incidence of bladder cancer [p (trend) = 0.08]. Among men there was an inverse association between the consumption of regular soft drinks and the incidence of bladder cancer [p (trend) = 0.03]. No association was found between the incidence of bladder cancer and the intake of water, coffee, tea, diet soft drinks, alcohol, or liquids from tap for men or women. This study suggests that the intake of water and specific beverages is overall not associated with risks of bladder cancer. This study provides limited evidence of a positive association between total fluid intake and bladder cancer among women.

Bladder cancer, tobacco smoking, coffee and alcohol drinking in Brescia, northern Italy

The association between tobacco smoking, the consumption of coffee and alcohol and bladder cancer was investigated in a hospital-based case-control study in Brescia, northern Italy. A total of 172 incident cases (135 men and 37 women) and 578 controls (398 men and 180 women) were enrolled. As expected, cigarette smoking was strongly associated with bladder cancer. The odds ratios (OR) for coffee drinking adjusted for age, education, residence and cigarette smoking in current drinkers were 2.6 (95% confidence interval, CI: 1.1-6.1) in men and 5.2 (95% CI: 1.0-30.4) in women. A dose-response relationship was found in men, with the highest risk in the highest category of exposure: drinkers of more than 5 cups per day had an OR of 4.5 (95% CI: 1.2-16.8). The ORs for current alcohol drinkers were 2.1 (95% CI: 1.0-4.8) in men and 3.4 (95% CI: 1.2-9.7) in women; according to grams of ethanol drunk per day (grams/day, g/d) the ORs were: 1.7 (1-20 g/d), 1.6 (21-40 g/d), 4.3 (41-60 g/d) and 4.6 (61+ g/d) in men and 3.1 (1-20 g/d) and 3.9 (21+ g/d) in women. These results suggest that regular consumption of both coffee and alcohol can be independently associated with an increased bladder cancer risk.

Nutrition and bladder cancer

Epidemiologic evidence on the relation between nutrition and bladder cancer is reviewed. A role of diet and nutrition in bladder carcinogenisis is plausible since most substances or metabolites, including carcinogens, are excreted through the urinary tract. Ecologic studies on populations have found positive correlations between fats and oils and bladder cancer, but these are reflected only partly in the international differences in bladder cancer rates, which are systematically higher in Europe than in the United States. Ten case-control and three cohort studies of bladder cancer published in English between 1979 and 1994, and including some information on dietary factors, were reviewed. Of seven studies which considered various types and measures of fruit and vegetable consumption, six found a reduced risk with increasing consumption, which was more consistent for vegetables, with relative risk (RR) estimates between 0.5 and 0.7 for the highest cf the lowest consumption level. There is, therefore, suggestive evidence that a diet rich in fresh fruit and vegetables is a correlate--or an indicator--of reduced bladder cancer risk. No clear association emerged for other foods investigated, including meat and milk. With reference to nutrients, total fat intake was related to bladder cancer risk in three case-control studies, with relative risks between 1.4 and 1.7 for the highest cf the lowest consumption level. However, no relationship between fats and bladder cancer emerged in a cohort study on Japanese-Americans in Hawaii. No consistent association emerged between protein or carbohydrate consumption and bladder cancer risk. Among micronutrients, vitamin A, and particularly carotenoids, showed an inverse association with bladder cancer risk in four case-control studies, including one allowing for a measure of total caloric intake, but were not related consistently in two other studies. There were only scattered and inconclusive data on vitamin C and E. Finally, two studies suggested that calcium and sodium may be related to bladder cancer risk. Thus, available data on diet and bladder cancer are still inconclusive. This is at least partly attributable to the limited number of cohort studies and the paucity of case-control studies, including satisfactorily detailed and validated dietary questionnaires. Despite these limitations, available data suggest that a diet rich in fresh fruit and vegetables, and, hence, possibly in carotenoids, is a correlate of reduced bladder cancer risk.