Bladder cancer in nonsmokers

Pesticides and Bladder Cancer: Mechanisms Leading to Anti-Cancer Drug Chemoresistance and New Chemosensitization Strategies

Multiple risk factors have been associated with bladder cancer. This review focuses on pesticide exposure, as it is not currently known whether agricultural products have a direct or indirect effect on bladder cancer, despite recent reports demonstrating a strong correlation. While it is known that pesticide exposure is associated with an increased risk of bladder cancer in humans and dogs, the mechanism(s) by which specific pesticides cause bladder cancer initiation or progression is unknown. In this narrative review, we discuss what is currently known about pesticide exposure and the link to bladder cancer. This review highlights multiple pathways modulated by pesticide exposure with direct links to bladder cancer oncogenesis/metastasis (MMP-2, TGF-β, STAT3) and chemoresistance (drug efflux, DNA repair, and apoptosis resistance) and potential therapeutic tactics to counter these pesticide-induced affects.

Firefighting and Cancer: A Meta-analysis of Cohort Studies in the Context of Cancer Hazard Identification

Objective

We performed a meta-analysis of epidemiological results for the association between occupational exposure as a firefighter and cancer as part of the broader evidence synthesis work of the IARCMonographs program.

Methods

A systematic literature search was conducted to identify cohort studies of firefighters followed for cancer incidence and mortality. Studies were evaluated for the influence of key biases on results. Random-effects meta-analysis models were used to estimate the association between ever-employment and duration of employment as a firefighter and risk of 12 selected cancers. The impact of bias was explored in sensitivity analyses.

Results

Among the 16 included cancer incidence studies, the estimated meta-rate ratio, 95% confidence interval (CI), and heterogeneity statistic (I2) for ever-employment as a career firefighter compared mostly to general populations were 1.58 (1.14-2.20, 8%) for mesothelioma, 1.16 (1.08-1.26, 0%) for bladder cancer, 1.21 (1.12-1.32, 81%) for prostate cancer, 1.37 (1.03-1.82, 56%) for testicular cancer, 1.19 (1.07-1.32, 37%) for colon cancer, 1.36 (1.15-1.62, 83%) for melanoma, 1.12 (1.01-1.25, 0%) for non-Hodgkin lymphoma, 1.28 (1.02-1.61, 40%) for thyroid cancer, and 1.09 (0.92-1.29, 55%) for kidney cancer. Ever-employment as a firefighter was not positively associated with lung, nervous system, or stomach cancer. Results for mesothelioma and bladder cancer exhibited low heterogeneity and were largely robust across sensitivity analyses.

Conclusions

There is epidemiological evidence to support a causal relationship between occupational exposure as a firefighter and certain cancers. Challenges persist in the body of evidence related to the quality of exposure assessment, confounding, and medical surveillance bias.

Secondhand smoking increases bladder cancer risk in nonsmoking population: a meta-analysis

Background

Tobacco smoking has been widely acknowledged to be the most important risk factor for bladder cancer. However, whether secondhand smoking (SHS) increases the risk of bladder cancer still remains uncertain. We conducted a meta-analysis about the risk of bladder cancer and lifetime SHS and childhood SHS.

Materials and methods

We searched PubMed, EMBASE, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) up to March 12, 2018, and checked references of the retrieved articles and relevant reviews to include 14 studies. Relative risk (RR) and 95% confidence interval (CI) were used to assess this risk.

Results

The pooled RR of 14 eligible studies based on the retrieved articles and relevant reviews illustrated a significantly increased risk of bladder cancer with RR 1.22, 95% CI 1.06–1.4. No heterogeneity or publication bias was found. But we need more evidence to prove a more reliable association between childhood SHS and bladder cancer.

Conclusion

There was a statistically significant 22% increased risk of bladder cancer for lifetime SHS exposure in nonsmoking patients compared with unexposed nonsmoking population. But the association between childhood SHS exposure compared with unexposed nonsmoking population was unclear. Further research should be conducted to confirm our findings and reveal the potential biological mechanisms.

A Stratified Meta-Analysis of the Association between Exposure to Environmental Tobacco Smoke during Childhood and Adulthood and Urothelial Bladder Cancer Risk

Background: Active smoking is a major risk factor for urothelial bladder cancer (UBC). However, the evidence that exposure to environmental tobacco smoke (ETS) either in childhood or adult life is also associated with UBC risk is ambiguous. With this meta-analysis, we aim to summarise how exposure to ETS is associated with UBC risk. Methods: In total, 11 studies (3 cohort studies, 8 case-control studies) were included in this meta-analysis and summary odds ratios (SORs) for UBC risk were calculated for never smokers who were exposed to ETS during childhood at home, during adulthood at home, or during adulthood in a work environment compared to never smokers who were never exposed to ETS. Sensitivity analyses were conducted to test the robustness of findings. Results: Never smokers exposed to ETS during childhood (SOR = 1.04, 95% confidence interval (CI) = 0.82-1.26), during adulthood at work (SOR = 0.98, 95% CI = 0.78-1.18) or at home (SOR = 0.99, 95% CI = 0.83-1.15) were at a similar risk of UBC compared to never smokers who were never exposed to ETS. Results for males and females were similar. Also, when pooling all estimates during both childhood and adulthood, no effect was observed (SOR = 1.00, 95% CI = 0.89-1.10). Conclusions: Although measurement of exposure to ETS was imprecise, there does not seem to be an association between UBC risk and exposure to ETS during childhood or adulthood. However, the current body of evidence mostly overlooks the duration and intensity of exposure to ETS.

Epidemiological evidence on environmental tobacco smoke and cancers other than lung or breast

We reviewed 87 epidemiological studies relating environmental tobacco smoke (ETS) exposure to risk of cancer other than lung or breast in never smoking adults. This updates a 2002 review which also considered breast cancer. Meta-analysis showed no significant relationship with ETS for nasopharynx cancer, head and neck cancer, various digestive cancers (stomach, rectum, colorectal, liver, pancreas), or cancers of endometrium, ovary, bladder and brain. For some cancers (including oesophagus, colon, gall bladder and lymphoma) more limited data did not suggest a relationship. An increased cervix cancer risk (RR 1.58, 95%CI 1.29-1.93, n = 17 independent estimates), reducing to 1.29 (95%CI 1.01-1.65) after restriction to five estimates adjusting for HPV infection or sexual activity suggests a causal relationship, as do associations with nasosinus cancer observed in 2002 (no new studies since), and less so kidney cancer (RR 1.33, 95%CI 1.04-1.70, n = 6). A weaker association with total cancer (RR 1.13, 95%CI 1.03-1.35, n = 19) based on heterogeneous data is inconclusive. Inadequate confounder control, recall bias, publication bias, and occasional reports of implausibly large RRs in individual studies contribute to our conclusion that the epidemiological evidence does not convincingly demonstrate that ETS exposure causes any of the cancers studied.

Occupational exposure to pesticides and bladder cancer risk

BACKGROUND

In the developed world, occupational exposures are a leading cause of bladder cancer. A few studies have suggested a link between pesticide exposures among agricultural populations and bladder cancer.

METHODS

We used data from the Agricultural Health Study, a prospective cohort study which includes 57 310 pesticide applicators with detailed information on pesticide use, to evaluate the association between pesticides and bladder cancer. We used Poisson regression to calculate rate ratios (RRs) and 95% confidence intervals (CIs) to estimate the association between each of 65 pesticides and 321 incident bladder cancer cases which accrued over the course of follow-up (1993-2011), adjusting for lifestyle and demographic and non-pesticide farm-related exposures, including those previously linked to bladder cancer. We conducted additional analyses stratified by smoking status (never, former, current).

RESULTS

We observed associations with bladder cancer risk for two imidazolinone herbicides, imazethapyr and imazaquin, which are aromatic amines. Ever use of imazaquin (RR = 1.54, 95% CI: 1.05, 2.26) was associated with increased risk whereas the excess risk among users of imazethapyr was evident among never smokers (RR in highest quartile vs non-exposed = 3.03, 95% CI: 1.46, 6.29, P-interaction = 0.005). We also observed increased risks overall and among never smokers for use of several chlorinated pesticides including chlorophenoxy herbicides and organochlorine insecticides.

CONCLUSIONS

Several associations between specific pesticides and bladder cancer risk were observed, many of which were stronger among never smokers, suggesting that possible risk factors for bladder cancer may be more readily detectable in those unexposed to potent risk factors like tobacco smoke.

A case-control study of occupational exposure to metalworking fluids and bladder cancer risk among men

OBJECTIVES

Metalworking has been associated with an excess risk of bladder cancer in over 20 studies. Metalworking fluids (MWFs) are suspected as the responsible exposure, but epidemiological data are limited. We investigated this association among men in the New England Bladder Cancer Study using state-of-the-art, quantitative exposure assessment methods.

METHODS

Cases (n=895) and population controls (n=1031) provided occupational histories during personal interviews. For selected jobs, exposure-oriented modules were administered to collect information on use of three MWF types: (1) straight (mineral oil, additives), (2) soluble (mineral oil, water, additives) and (3) synthetic (water, organics, additives) or semisynthetic (hybrid of soluble and synthetic). We computed ORs and 95% CIs relating bladder cancer risk to a variety of exposure metrics, adjusting for smoking and other factors. Non-metalworkers who had held jobs with possible exposure to mineral oil were analysed separately.

RESULTS

Bladder cancer risk was elevated among men who reported using straight MWFs (OR=1.7, 95% CI 1.1 to 2.8); risk increased monotonically with increasing cumulative exposure (p=0.041). Use of soluble MWFs was associated with a 50% increased risk (95% CI 0.96 to 2.5). ORs were non-significantly elevated for synthetic/semisynthetic MWFs based on a small number of exposed men. Non-metalworkers holding jobs with possible exposure to mineral oil had a 40% increased risk (95% CI 1.1 to 1.8).

CONCLUSIONS

Exposure to straight MWFs was associated with a significantly increased bladder cancer risk, as was employment in non-metalworking jobs with possible exposure to mineral oil. These findings strengthen prior evidence for mineral oil as a bladder carcinogen.

Urinary dysfunction in children is associated with exposure to environmental tobacco smoke

OBJECTIVE

Environmental tobacco smoke (ETS) is known to cause significant morbidity across a wide variety of organ systems. The purpose of this study was to examine the relationship of ETS exposure with pediatric urinary dysfunction.

PATIENTS AND METHODS

Participants were drawn from a university-based pediatric urology practice throughout the first half of 2011. All patients who presented with a chief complaint of urinary dysfunction were approached to participate (N = 184). Exclusion criteria eliminated all but 71 subjects. Of these, 68 subjects and their parents completed age-appropriate questionnaires on ETS exposure and symptom severity. Data were analyzed using descriptive statistics and relationship between exposure and outcome was evaluated via Spearman correlation analysis.

RESULTS

A total of 68 children with no known etiology for their urinary dysfunction were evaluated for symptom severity and ETS exposure. Participants demonstrated a significant positive correlation (rho = 0.592 for those 4-10 years; rho = 0.415 for those 11-17 years) between ETS exposure and severity of their urinary symptoms.

CONCLUSIONS

These data indicate a positive relationship between ETS exposure and urinary dysfunction among children with no other obvious etiology for their symptoms. Physicians should inform parents of the potential dangers of childhood ETS exposure, including the possible relationship with urinary dysfunction.

Association between the high risk occupations and bladder cancer in Iran: a case-control study

OBJECTIVES

The objective of this work was to identify the high-risk occupations in Iran and to re-inspect occupations that were related to bladder cancer.

MATERIALS AND METHODS

In the study, 300 patients suffering from bladder cancer and 500 control individuals were interviewed. Demographic information, occupational history, and history of exposure to chemical compounds such as aromatic amines for each participant were collected. ORs and 95% CIs were calculated using unconditional logistic regression for each occupation.

RESULTS

There was a significantly increased risk of bladder cancer among truck and bus drivers (OR = 11.3), skilled agricultural, forestry and fishery workers (OR = 6.0), metal industry workers (OR = 6.0), domestic housekeepers (OR = 5.9), and construction workers (OR = 3.8).

CONCLUSIONS

The study showed a strong correlation between truck and bus drivers, skilled agricultural, forestry and fishery workers, metal industry workers, domestic housekeepers, as well as construction workers and the increased risk of bladder cancer in these occupations.

Evaluation of a bladder cancer cluster in a population of criminal investigators with the Bureau of Alcohol, Tobacco, Firearms and Explosives--part 2: the association of cancer risk and fire scene investigation

This study evaluated the association of bladder cancer risk and fire scene investigation within a cohort of white male criminal investigators with the United States Bureau of Alcohol, Tobacco, Firearms and Explosives that was found to be at increased risk for bladder cancer. Medical surveillance data were used in a nested case-control study to determine odds ratios (ORs) estimating the relative risk of the cancer associated with post-fire investigation. The study comprised seven bladder cancer cases and 1525 controls. Six of the cases reported holding assignments associated with post-fire investigation. The OR for bladder cancer was 19.01 (95% confidence interval = 1.94-186.39) for those holding any one or more of these assignments for one to four years versus zero years and 12.56 (1.14-138.58) for those holding any one or more of these assignments for five or more years versus zero years. The risk for bladder cancer is significantly elevated for those holding post-fire investigation assignments compared to those not holding these assignments.

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

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

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Environmental tobacco smoke in relation to bladder cancer risk--the Shanghai bladder cancer study [corrected]

BACKGROUND

Environmental tobacco smoke (ETS) contains tobacco carcinogens. Hepatic cytochrome P450 (CYP) 1A2 and N-acetyltransferase (NAT2) are important isoenzymes in activation and detoxification, respectively, of tobacco carcinogens. Data on ETS and bladder cancer risk are sparse.

METHODS

We examined the effects of ETS alone and combined with NAT2/CYP1A2 on bladder cancer risk among lifelong-nonsmokers in a case-control study involving 195 patients and 261 controls in Shanghai, China. A comprehensive history of ETS exposure was determined through in-person interviews while CYP1A2 and NAT2 phenotypes by a caffeine-based urinary assay.

RESULTS

ETS exposure was related to an overall statistically nonsignificant 38% increased bladder cancer risk. The risk increased with increasing number of cigarettes smoked by household members or number of hours per day at workplace where coworkers smoked. Compared with no ETS exposure, subjects living with smoking parents during childhood had an OR of 2.43 (95% CI = 0.99-5.96) for bladder cancer. When all ETS sources were combined, the risk increased with increasing total ETS score (P(trend) = 0.03). The OR for high versus nil ETS exposure was 3.00 (95% CI = 1.24-7.26). The increased risk with ETS was mainly seen among individuals possessing a CYP1A2 high efficiency and/or a NAT2 slow acetylation phenotype (P(trend) = 0.04).

CONCLUSIONS

ETS was associated with an increased bladder cancer risk for lifelong-nonsmokers. The association was stronger for people possessing the at-risk phenotypes of CYP1A2 and/or NAT2.

IMPACT

Reducing exposure to ETS for children and genetically more susceptible individuals could be more effective for bladder cancer prevention.

Occupation and bladder cancer in a population-based case-control study in Northern New England

OBJECTIVES

We used data from a large, population-based case-control study in Maine, New Hampshire, and Vermont to examine relationships between occupation, industry and bladder cancer risk.

METHODS

Lifetime occupational histories were obtained by personal interview from 1158 patients newly diagnosed with urothelial carcinoma of the bladder in 2001-2004, and from 1402 population controls. Unconditional logistic regression was used to calculate ORs and 95% CIs, adjusted for demographic factors, smoking and employment in other high-risk occupations.

RESULTS

Male precision metalworkers and metalworking/plasticworking machine operators had significantly elevated risks and significant trends in risk with duration of employment (precision metalworkers: OR 2.2, 95% CI 1.4 to 3.4, p(trend) = 0.0065; metalworking/plasticworking machine operators: OR 1.6, 95% CI 1.01 to 2.6, p(trend) = 0.047). Other occupations/industries for which risk increased significantly with duration of employment included: for men, textile machine operators, mechanics/repairers, automobile mechanics, plumbers, computer systems analysts, information clerks, and landscape industry workers; for women, service occupations, health services, cleaning and building services, management-related occupations, electronic components manufacturing and transportation equipment manufacturing. Men reporting use of metalworking fluids (MWF) had a significantly elevated bladder cancer risk (OR 1.7, 95% CI 1.1 to 2.5).

CONCLUSIONS

Our findings support the hypothesis that some component(s) of MWF may be carcinogenic to the bladder. Our results also corroborate many other previously reported associations between bladder cancer risk and various occupations. More detailed analyses using information from the study's job-specific questionnaires may help to identify MWF components that may be carcinogenic, and other bladder carcinogens associated with a variety of occupations.

Hypertension, diuretics and antihypertensives in relation to bladder cancer

The aim of this study is to investigate the relationships between hypertension, hypertension medication and bladder cancer risk in a population-based case-control study conducted in Los Angeles. Non-Asians between the ages of 25 and 64 years with histologically confirmed bladder cancers diagnosed between 1987 and 1996 were identified through the Los Angeles County Cancer Surveillance Program. A total of 1585 cases and their age-, gender- and race-matched neighborhood controls were included in the analyses. Conditional logistic regression models were used to examine the relationship between history of hypertension, medication use and bladder cancer risk. A history of hypertension was not related to bladder cancer; however, among hypertensive individuals, there was a significant difference in bladder cancer risk related to the use of diuretics or antihypertensive drugs (P for heterogeneity = 0.004). Compared with individuals without hypertension, hypertensive individuals who regularly used diuretics/antihypertensives had a similar risk [odds ratio (OR) 1.06; 95% confidence interval (CI) 0.86-1.30], whereas untreated hypertensive subjects had a 35% reduction in risk (OR: 0.65; 95% CI: 0.48-0.88). A greater reduction in bladder cancer risk was observed among current-smokers (OR: 0.43; 95% CI: 0.27-0.71) and carriers of GSTM1-null (homozygous absence) genotypes (OR: 0.43; 95% CI: 0.22-0.85). Similarly, among smokers with GSTM1-null genotype, levels of 4-aminobiphenyl-hemoglobin adducts were significantly lower among untreated hypertensive individuals (45.7 pg/g Hb) compared with individuals without hypertension (79.8 pg/g Hb) (P = 0.009). In conclusion, untreated hypertension was associated with a reduced risk of bladder cancer.

A case-control study of smoking and bladder cancer risk: emergent patterns over time

BACKGROUND

Cigarette smoking is a well-established risk factor for bladder cancer. The effects of smoking duration, intensity (cigarettes per day), and total exposure (pack-years); smoking cessation; exposure to environmental tobacco smoke; and changes in the composition of tobacco and cigarette design over time on risk of bladder cancer are unclear.

METHODS

We examined bladder cancer risk in relation to smoking practices based on interview data from a large, population-based case-control study conducted in Maine, New Hampshire, and Vermont from 2001 to 2004 (N = 1170 urothelial carcinoma case patients and 1413 control subjects). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression. To examine changes in smoking-induced bladder cancer risk over time, we compared odds ratios from New Hampshire residents in this study (305 case patients and 335 control subjects) with those from two case-control studies conducted in New Hampshire in 1994-1998 and in 1998-2001 (843 case patients and 1183 control subjects).

RESULTS

Regular and current cigarette smokers had higher risks of bladder cancer than never-smokers (for regular smokers, OR = 3.0, 95% CI = 2.4 to 3.6; for current smokers, OR = 5.2, 95% CI = 4.0 to 6.6). In New Hampshire, there was a statistically significant increasing trend in smoking-related bladder cancer risk over three consecutive periods (1994-1998, 1998-2001, and 2002-2004) among former smokers (OR = 1.4, 95% CI = 1.0 to 2.0; OR = 2.0, 95% CI = 1.4 to 2.9; and OR = 2.6, 95% CI = 1.7 to 4.0, respectively) and current smokers (OR = 2.9, 95% CI = 2.0 to 4.2; OR = 4.2, 95% CI = 2.8 to 6.3; OR = 5.5, 95% CI = 3.5 to 8.9, respectively) (P for homogeneity of trends over time periods = .04). We also observed that within categories of intensity, odds ratios increased approximately linearly with increasing pack-years smoked, but the slope of the increasing trend declined with increasing intensity.

CONCLUSIONS

Smoking-related risks of bladder cancer appear to have increased in New Hampshire since the mid-1990s. Based on our modeling of pack-years and intensity, smoking fewer cigarettes over a long time appears more harmful than smoking more cigarettes over a shorter time, for equal total pack-years of cigarettes smoked.

Systematic review of the relation between smokeless tobacco and cancer in Europe and North America

BACKGROUND

Interest is rising in smokeless tobacco as a safer alternative to smoking, but published reviews on smokeless tobacco and cancer are limited. We review North American and European studies and compare effects of smokeless tobacco and smoking.

METHODS

We obtained papers from MEDLINE searches, published reviews and secondary references describing epidemiological cohort and case-control studies relating any form of cancer to smokeless tobacco use. For each study, details were abstracted on design, smokeless tobacco exposure, cancers studied, analysis methods and adjustment for smoking and other factors. For each cancer, relative risks or odds ratios with 95% confidence intervals were tabulated. Overall, and also for USA and Scandinavia separately, meta-analyses were conducted using all available estimates, smoking-adjusted estimates, or estimates for never smokers. For seven cancers, smoking-attributable deaths in US men in 2005 were compared with deaths attributable to introducing smokeless tobacco into a population of never-smoking men.

RESULTS

Eighty-nine studies were identified; 62 US and 18 Scandinavian. Forty-six (52%) controlled for smoking. Random-effects meta-analysis estimates for most sites showed little association. Smoking-adjusted estimates were only significant for oropharyngeal cancer (1.36, CI 1.04-1.77, n = 19) and prostate cancer (1.29, 1.07-1.55, n = 4). The oropharyngeal association disappeared for estimates published since 1990 (1.00, 0.83-1.20, n = 14), for Scandinavia (0.97, 0.68-1.37, n = 7), and for alcohol-adjusted estimates (1.07, 0.84-1.37, n = 10). Any effect of current US products or Scandinavian snuff seems very limited. The prostate cancer data are inadequate for a clear conclusion.Some meta-analyses suggest a possible effect for oesophagus, pancreas, larynx and kidney cancer, but other cancers show no effect of smokeless tobacco. Any possible effects are not evident in Scandinavia. Of 142,205 smoking-related male US cancer deaths in 2005, 104,737 are smoking-attributable. Smokeless tobacco-attributable deaths would be 1,102 (1.1%) if as many used smokeless tobacco as had smoked, and 2,081 (2.0%) if everyone used smokeless tobacco.

CONCLUSION

An increased risk of oropharyngeal cancer is evident most clearly for past smokeless tobacco use in the USA, but not for Scandinavian snuff. Effects of smokeless tobacco use on other cancers are not clearly demonstrated. Risk from modern products is much less than for smoking.

Secondhand smoking, 4-aminobiphenyl, and bladder cancer: two meta-analyses

OBJECTIVE

To quantify the relation between secondhand smoking (SHS) and levels of 4-aminobiphenyl (4-ABP; in urine or blood) and SHS and bladder cancer risk in nonsmokers.

METHODS

PubMed and Embase were searched (search terms to represent SHS, bladder cancer, and 4-ABP) to conduct two meta-analyses. Information about gender and age of participants, mean 4-ABP level for each SHS category, number of subjects, relative risk or odds ratio and 95% confidence intervals (95% CI) in each SHS category, and covariates for which adjustment was made was extracted based on predefined inclusion and exclusion criteria. Random-effects analyses were done using STATA (version 9).

RESULTS

A 118 studies were reviewed for information on SHS and 4-ABP (31 studies) and SHS and bladder cancer risk (87 studies). Of those, seven case-control studies were included for analysis of SHS and 4-ABP and eight articles (three cohort and five case-control studies) for SHS and bladder cancer risk. A random-effects model found a pooled standardized mean difference of 1.47 (95% CI, 0.23-2.71), indicating higher levels of 4-ABP among nonsmokers exposed to SHS. A random-effects model showed no evidence for an association between SHS and bladder cancer risk (relative risk, 0.99; 95% CI, 0.86-1.14), comparing nonsmokers with and without SHS exposure.

CONCLUSION

Higher levels of 4-ABP were significantly associated with SHS exposure, which is consistent with earlier findings for 4-ABP levels in sidestream smoke. The current evidence indicates that there is no association between SHS and bladder cancer, but future studies that address methodologic limitations are needed to further clarify this important question.

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.

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.

Diabetes mellitus, body size and bladder cancer risk in a prospective study of Swedish men

Epidemiologic studies on diabetes and body size in relation to risk of bladder cancer have yielded inconsistent results. We examined prospectively the associations between a history of diabetes, height, weight, body mass index and waist circumference, and the incidence of bladder cancer in the Cohort of Swedish Men, a prospective study of 45,906 men aged 45-79 years at baseline. During follow-up from 1998 through December 2007, 414 incident cases of bladder cancer were ascertained. A history of diabetes was not associated with risk of bladder cancer (multivariate rate ratio=1.16; 95% confidence interval=0.81-1.64). Similarly, no associations were observed for height, weight, body mass index or waist circumference. These findings in men do not support a role for diabetes, height or excess body mass in the aetiology of bladder cancer.

Environmental Tobacco Smoke and Bladder Cancer Risk in Never Smokers of Los Angeles County

Cigarette smoking is a major risk factor for bladder cancer and a prominent point source of 4-aminobiphenyl (4-ABP), a recognized human bladder carcinogen. 4-ABP-hemoglobin (Hb) adducts are established biomarkers of 4-ABP exposure in humans. The role of environmental tobacco smoke (ETS) in the etiology of bladder cancer is largely unknown. As part of a large population-based bladder cancer study in Los Angeles County, California, lifetime exposure to ETS was ascertained for 148 cases and 292 control subjects who had never used any tobacco products over their lifetime. 4-ABP-Hb adducts were quantitatively measured on 230 control subjects. Female lifelong nonsmokers living with two or more smokers during childhood were significantly related to risk of bladder cancer [odds ratio (OR), 3.08; 95% confidence interval (95% CI), 1.16-8.22]. During adulthood, approximately 2-fold risks were seen among women living with a spouse/domestic partner who smoked for > or =10 years or having a coworker who smoked in an indoor environment for > or =10 years. When all sources of ETS exposure were combined, a statistically significant, dose-dependent association (P for trend = 0.03) was noted in women, with the OR for the highest category of ETS exposure being 5.48 (95% CI, 1.06-28.36). Levels of 4-ABP-Hb adducts varied by ETS exposure status among female control subjects. Mean level was lowest in women never exposed to ETS (16.4 pg/g Hb) and highest in those with current ETS exposure (23.6 pg/g Hb). ETS exposure was associated with neither bladder cancer risk nor 4-ABP-Hb adduct levels in male lifelong nonsmokers. In conclusion, ETS is a risk factor for bladder cancer in women who were lifelong nonusers of any tobacco products.

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

AIMS/HYPOTHESIS

Epidemiological evidence indicates that individuals with diabetes mellitus have an increased risk of several cancers. We performed a systematic review with meta-analysis to evaluate the association between diabetes and risk of bladder cancer.

METHODS

Pertinent studies were identified by searching MEDLINE (from January 1966 to July 2006) and by reviewing the reference lists of retrieved articles. We included case-control and cohort studies reporting relative risk (RR) estimates with 95% CIs (or data to calculate them) of bladder cancer associated with diabetes. Studies of type 1 diabetes were not included. Summary RRs were calculated using a random-effects model.

RESULTS

A total of 16 studies (seven case-control studies, three cohort studies and six cohort studies of diabetic patients) fulfilled the inclusion criteria. Analysis of all studies showed that diabetes was associated with an increased risk of bladder cancer, compared with no diabetes (RR = 1.24, 95% CI 1.08-1.42). There was strong evidence of heterogeneity among these studies (p < 0.0001). Stratification by study design found that diabetes was associated with an increased risk of bladder cancer in case-control studies (RR = 1.37, 95% CI 1.04-1.80, p (heterogeneity) = 0.005) and cohort studies (RR = 1.43, 95% CI 1.18-1.74, p (heterogeneity) = 0.17), but not in cohort studies of diabetic patients (RR = 1.01, 95% CI 0.91-1.12, p (heterogeneity) = 0.35).

CONCLUSIONS/INTERPRETATION

Findings from this meta-analysis suggest that individuals with diabetes may have a modestly increased risk of bladder cancer.

Tobacco smoke and bladder cancer--in the European Prospective Investigation into Cancer and Nutrition

The purpose of the present study was to investigate the association between smoking and the development of bladder cancer. The study population consisted of 429,906 persons participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), 633 of whom developed bladder cancer during the follow-up period. An increased risk of bladder cancer was found for both current- (incidence rate ratio 3.96, 95% confidence interval: 3.07-5.09) and ex- (2.25, 1.74-2.91) smokers, compared to never-smokers. A positive association with intensity (per 5 cigarettes) was found among current-smokers (1.18, 1.09-1.28). Associations (per 5 years) were observed for duration (1.14, 1.08-1.21), later age at start (0.75, 0.66-0.85) and longer time since quitting (0.92, 0.86-0.98). Exposure to environmental tobacco smoke (ETS) during childhood increased the risk of bladder cancer (1.38, 1.00-1.90), whereas for ETS exposure as adult no effect was detected. The present study confirms the strong association between smoking and bladder cancer. The indication of a higher risk of bladder cancer for those who start smoking at a young age and for those exposed to ETS during childhood adds to the body of evidence suggesting that children are more sensitive to carcinogens than adults.

Clinico-pathological features of bladder carcinoma in women in Pakistan and smokeless tobacco as a possible risk factor

BACKGROUND

Bladder carcinoma is one of the common urological malignancies occurring worldwide in both sexes. Use of smokeless tobacco by women is common in rural areas of Pakistan. The clinico-pathological features of bladder carcinoma in women and association of smokeless tobacco as a possible risk factor for bladder carcinoma has not been well described in the literature. The objective of the study was to determine the clinico-pathological features of histologically confirmed bladder carcinoma in women and to investigate the role of smokeless tobacco use as a possible risk factor for its development.

PATIENTS AND METHODS

Of the 204 patients (160 male and 44 female M:F ratio 3.6:1) of newly diagnosed bladder carcinoma treated at Nishtar Medical College Hospital Multan from January 1998 to December 2004, the 44 female patients were evaluated with respect to age, clinical presentation, cystoscopic findings, histopathological reports and possible etiological factors. Data were collected and prospectively updated at the time of discharge from hospital and during follow-up in urology out-patient clinic.

RESULTS

Transitional cell carcinoma accounted for all of the bladder carcinoma in women. Median age of the patients was 55 years and 68% patients were under 60 years of age. Majority of patients (88%) presented with hematuria. Eleven (25%) patients had superficial (pTa/pT1) while 33 (75%) patients had muscle invasive (T2-T4) bladder carcinoma. Most (81%) superficial tumors were papillary while muscle invasive tumors had solid configuration at cystoscopy. Of these, 21 (47%) patients had long history of smokeless tobacco use (chewable or moist snuff).

CONCLUSION

Transitional cell carcinoma is the most common bladder malignancy in women in Pakistan. Many women with bladder carcinoma had long history of use of smokeless tobacco. Majority of patients presented with hematuria and were under 60 years of age. At the time of diagnosis 75% women had muscle invasive bladder carcinoma. In women using smokeless tobacco, the correlation between stage of bladder carcinoma and duration of smokeless tobacco use was significant (p = 0.03). Further studies are needed to clarify the role of smokeless tobacco in the development of bladder carcinoma.

Environmental tobacco smoke and cancer of sites other than the lung in adult non-smokers

Evidence from epidemiological studies relating environmental tobacco smoke (ETS) exposure to risk of cancer of sites other than the lung in adult non-smokers is reviewed. Problems common to many studies include small sample size, inadequate control of potential confounding, failure to consider the possibility of misclassification of smoking status, reliance on death certificate diagnosis, use of proxy respondents and the possibility of recall bias. A number of the studies have other obvious weaknesses. Publication bias is known to be a problem, with two very large prospective studies having reported only very limited results. For cancers of the digestive system, bladder and brain, there is little evidence of an association with ETS exposure. Some studies have reported a relationship with cancer of the breast, cervix or nasopharynx, but the overall evidence for these sites is inconsistent and inconclusive, as is that for total cancer incidence. All three studies of nasosinus cancer have reported a statistically significant association with ETS exposure, but they are small, control poorly for potential confounding and have other weaknesses. Taken as a whole, the epidemiological evidence provides little support for the view that ETS causes cancer of any of the sites considered.

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.

Occupational risk factors for urothelial carcinoma: agent-specific results from a case-control study in Germany. MURC Study Group. Multicenter Urothelial and Renal Cancer

BACKGROUND

This multicentre population-based case-control study was conducted to estimate the urothelial cancer risk for occupational exposure to aromatic amines, polycyclic aromatic hydrocarbons (PAH), and chlorinated hydrocarbons besides other suspected risk factors.

METHODS

In a population-based multicentre study, 1035 incident urothelial cancer cases and 4298 controls matched for region, sex, and age were interviewed between 1991 and 1995 for their occupational history and lifestyle habits. Exposure to the agents under study was self-assessed as well as expert-rated with two job-exposure matrices and a job task-exposure matrix. Conditional logistic regression was used to calculate smoking adjusted odds ratios (OR) and to control for study centre and age.

RESULTS

Urothelial cancer risk following exposure to aromatic amines was only slightly elevated. Among males, substantial exposures to PAH as well as to chlorinated solvents and their corresponding occupational settings were associated with significantly elevated risks after adjustment for smoking (PAH exposure, assessed with a job-exposure matrix: OR = 1.6, 95% CI: 1.1-2.3, exposure to chlorinated solvents, assessed with a job task-exposure matrix: OR = 1.8, 95% CI: 1.2-2.6). Metal degreasing showed an elevated urothelial cancer risk among males (OR = 2.3, 95% CI: 1.4-3.8). In females also, exposure to chlorinated solvents indicated a urothelial cancer risk. Because of small numbers the risk evaluation for females should be treated with caution.

CONCLUSIONS

Occupational exposure to aromatic amines could not be shown to be as strong a risk factor for urothelial carcinomas as in the past. A possible explanation for this finding is the reduction in exposure over the last 50 years. Our results strengthen the evidence that PAH may have a carcinogenic potential for the urothelium. Furthermore, our results indicate a urothelial cancer risk for the use of chlorinated solvents.

Cancer in printing workers in Denmark

OBJECTIVES

To study the cancer incidence in printing workers in Denmark.

METHODS

The cohort of 15,534 men and 3593 women working in the printing industry in 1970 were followed up for death, emigrations, and incident cancer cases until the end of 1987. Their cancer incidence was compared with that of all economically active people in Denmark. The smoking and drinking habits reported by members of the printing trade unions at a survey in 1972 were compared with habits reported by members of other trade unions.

RESULTS

Lung, bladder, renal pelvis, and primary liver cancers were in excess among the printing workers. The excess risks of lung cancer among the factory workers in newspaper and magazine production, of bladder cancer in typographers in printing establishments, of renal pelvis cancer in typographers and lithographers, and of primary liver cancer among lithographers and bookbinders exceeded those expected based on the reported smoking and drinking habits.

CONCLUSION

Our results indicate, in line with a previous study from Manchester, that work with rotary letterpress printing was associated with an increased risk of lung cancer. The inconsistent results from studies on bladder cancer in printing workers may point to a risk confined to a certain subgroup. The sixfold risk of primary liver cancer in Danish lithographers warrants studies in other countries.

Bladder cancer among French farmers: does exposure to pesticides in vineyards play a part?

OBJECTIVE

To appraise the potential contribution of pesticides sprayed on vineyards to the genesis of bladder cancer among agricultural workers.

METHODS

A pesticide exposure index (PEI), based on labour time and the proportion of agricultural land used as vineyards, was constructed for 89 French geographical units (départements). The standardised mortality ratios (SMRs) for bladder cancer, as well as tobacco consumption and economic status of male farmers and farm labourers aged 35-74 in the same areas were estimated for the period 1984-6. Models were fitted to the geographical data with Poisson regressions and extra-Poisson models with geographically structured and unstructured random effects.

RESULTS

Mortality from bladder cancer among farmers was lower (but not significantly so) than within the overall population (SMR 0.96, 95% confidence interval (95% CI) 0.85-1.08), but there was a significant link with exposure to pesticides in vineyards by univariate analysis (relative risk (RR) 1.17, 95% CI 1.10-1.24) and by multivariate analysis (RR 1.14, 95% CI 1.07-1.22).

CONCLUSION

These results add some evidence to the view that pesticides in vineyards cause mortality from bladder cancer among farmers, and could explain the French south-north gradient in bladder cancer, as vineyards are mainly located in Southern France.

Descriptive epidemiology of oral neoplasms in Sudan 1970-1985 and the role of toombak

Data from 1,916 cases of oral neoplasms occurring in the Sudan in a 16-year period, from January 1970 to December 1985, were retrieved and analysed. The study revealed a relatively high frequency of oral neoplasms in comparison with neighbouring countries. In this study, squamous-cell carcinoma was the most common oral malignancy (66.5%), followed by tumours of the salivary gland (14.7%), neoplasms of nonodontogenic and non-epithelial origin (9.6%) and odontogenic neoplasms (8.6%). Men had a higher frequency than women. The older age group of both genders showed a relatively high frequency of squamous-cell carcinoma. Among northern Sudanese there was a high rate of squamous-cell carcinoma, while southern Sudanese showed a high rate of odontogenic and salivary-gland neoplasms. The use of toombak has been stated to play a major role in the aetiology of oral squamous-cell carcinoma in the Sudan, and is suspected to be associated with neoplasms of the salivary glands.

A cross-national investigation of diet and bladder cancer

The existence of a large unexplained portion of attributable risk, and the marked variation in bladder cancer rates globally, have stimulated an interest in the role of nutrition in cancer of the urinary bladder. For this cross-national comparison study, we had complete data available for 50 countries. Using stepwise regression followed by general linear modelling, age-truncated (45-74 years), world-standardised, sex-specific bladder cancer mortality rates were regressed on an array of nutritional and socioeconomic independent variables in an effort to identify important predictors of bladder cancer mortality. Separate principal components analyses were used to summarise the nutritional and the socioeconomic (SES) variables. In the stepwise analyses, using food scores expressed in kcal/day per capita (as opposed to the nutritional components), total fat consistently entered the model first, and explained the greatest share of variability (R2) for both males and females. General linear models were fitted that included total fat, tobacco, alcohol, the three SES components (comprising seven socioeconomic predictors) and two food categories found significant in stepwise modelling, roots/tubers and vegetable oil. The R2 values were 0.84 for male rates and 0.77 for female rates, meaning that these study factors account for 84% of bladder cancer mortality in men and 77% in women. Substitution of the nutritional components for the foods resulted in general linear models with slightly higher R2 values (0.85 for males, 0.77 for females), but with attenuated fat effects. Results are discussed in light of biological plausibility.

Coffee, cigarette smoking, and bladder cancer in western New York

The association between consumption of coffee and bladder cancer and the effect modification of cigarette smoking was investigated as part of a comprehensive case-control study. The study population consisted of 351 case patients with histologically confirmed transitional cell carcinomas of the bladder among white males and 855 white male control subjects selected from Erie, Niagara, and Monroe counties in New York from 1979 to 1985. Usual diet, coffee consumption, and cigarette use were estimated by comprehensive interviews using a detailed food frequency questionnaire. After adjustment for age, education, and dietary risk factors by multiple logistic regression, risk was found to increase with increasing pack-years of cigarette use with an odds ratio in the highest quartile of 2.7 (95% confidence interval, 1.8 to 4.0) when compared to the lowest quartile. Coffee consumption was associated with an increased risk for bladder cancer among the heaviest coffee drinkers after adjustment for cigarette smoking and other dietary risk factors (odds ratio, 2.1; 95% confidence interval, 1.3 to 3.2). The effect was more pronounced among nonsmokers, especially among those 65 years and older. These findings support the contention that coffee is a weak carcinogen.

Bladder cancer and coffee drinking: a summary of case-control research

An association between coffee drinking and cancer of the lower urinary tract (LUT) was first suggested 20 years ago and has been the subject of many epidemiological studies. We have undertaken a critical review and statistical summary of 35 case-control studies of this association published between 1971 and 1992. Predefined methodological criteria were applied to the available reports. Studies were classified as either meeting the criteria (core studies) or failing to satisfy at least one of the requirements for design or analysis (non-core studies). The summarised data from the 8 core studies showed no evidence of an increase in risk of LUT cancer with coffee drinking in men or women after adjustment for the effects of cigarette smoking (odds ratio 1.07 [95% CI 1.00-1.14] for men, 0.91 [0.81-1.03] for women). The measures of association from the non-core studies were higher on average than those from the core studies, although the inclusion of these data in an overall summarised estimate did not substantially change the findings from the core analysis. We conclude that the best available data do not suggest a clinically important association between the regular use of coffee and development of cancer of the LUT in men or women.

Potential inhibitors of tobacco carcinogenesis

Tobacco smoking is causally associated with cancer of the lung, upper aerodigestive tract, pancreas, renal pelvis and urinary bladder. Tobacco chewers and especially snuff dippers face an increased risk for cancer of the oral cavity and pharynx. Although cessation of the tobacco habits is the only sure way to avoid an increased risk of tobacco-related cancers, certain modified products should be available to lower the incidence rates for cancer among those tobacco chewers and smokers who are unable to give up their tobacco habits. The modified cigarette has been the first approach toward the reduction of cancer risk. In the case of cancer of the lung, the long-term smoker of low-yield filter cigarettes has a risk reduction of 30-50% over that of the smoker of nonfilter cigarettes; however, the risk of filter cigarette smokers for cancer of the lung and cancer at other sites is still many times higher than that of the nonsmoker. A second modality is the application of natural or synthetic chemopreventive agents. Clinical studies with tobacco users have been primarily limited to the application of beta-carotene and retinoids. Although the data appear encouraging in respect to reducing early lesions in the oral cavity of tobacco chewers and smokers and in respect to second primaries in smokers, the benefits of beta-carotene and retinoids are gradually reversed upon withholding these micronutrients. It is understandable that activities in respect to chemopreventive agents in clinical trials on smokers are limited, since cessation of smoking alone leads within only a few years to a significant reduction of the cancer risk. Another reason for the limited interest in clinical trials on smokers may relate to the lack of laboratory data on the actual effects of chemopreventive agents in animals induced with tobacco-specific carcinogens. However, during the last few years, a number of natural or synthetic chemopreventive agents in animals induced with tobacco-specific carcinogens. However, during the last few years, a number of natural or synthetic chemopreventive agents have been tested in mice and rats which were treated with carcinogenic, tobacco-specific N-nitrosamines (TSNA). The results appear most encouraging in respect to lung tumor reduction. It is hoped that this type of research will gain in interest. Human data suggest that the fat content of the diet influences the cancer risk of smokers.(ABSTRACT TRUNCATED AT 400 WORDS)

Environmental tobacco smoke and the risk of cancer in adults

The apparent effect of environmental tobacco smoke (ETS) exposure on cancer risk has become an important social and political issue. The risk of cancer in non-smokers is often the main reason for prohibiting or restricting smoking in public places. A number of epidemiological studies have shown an association between ETS exposure and lung cancer. However, the strength of this association has still to be estimated. Only a few studies have reported on ETS and cancer from sites other than the lung in adults. No definite conclusions can be drawn at present from a critical review of the epidemiological evidence, but the suggestion of an association is present for sinonasal cancer, while bladder cancer does not seem to be associated to ETS exposure. Positive studies are available for cancers from other sites, including the breast, the uterine cervix and the brain, but these are difficult to interpret.

Investigation of a reported cluster of bladder cancer cases in the Pottstown/Phoenixville area of Pennsylvania

A urologist in Phoenixville, Pennsylvania, noted an apparent excess of invasive bladder cancer cases in his practice area during 1988 and 1989. Background incidence data for the local area were derived from state Cancer Registry statistics. Seventeen additional cases were noted during review of local hospital tumor registry data. Exposure evaluation included complete occupational histories for 15 index cases and correlation of residential histories with a review of local industries, water quality data, and toxic waste sites. The data were compared with incidence data from 1984 and 1985, and no increase in bladder cancer incidence for this area in 1988 and 1989 was evident. There was, however, a higher bladder cancer incidence among white males in the study area and Chester County, compared with Pennsylvania as a whole. Residential histories and environmental analysis did not reveal a common environmental carcinogen. A high incidence of occupational exposure to suspected bladder carcinogens was noted. In addition, all but 4 of the index cases smoked cigarettes. The study was limited by an extreme paucity of water supply analysis data. Effective environmental monitoring would promote more effective research into environmental carcinogenesis.

Coffee consumption and bladder cancer risk

The relation between consumption of regular and decaffeinated coffee and other methylxanthine-containing beverages and bladder cancer was analysed in a case-control study in two different areas of northern Italy (555 cases and 855 controls). The multivariate relative risk (RR) adjusted for smoking, occupation and sociodemographic variables for coffee drinkers versus non-drinkers was 1.3 (95% CI 1.0-1.8). The RR was 1.2 for one cup of coffee per day, 1.4 for two, 1.5 for three and 1.4 for four or more (P = 0.05). RRs for current drinkers were 1.5 (0.9-2.4) for decaffeinated coffee, 0.9 (0.6-1.2) for tea, and 0.6 (0.3-1.4) for cola. With reference to duration of consumption of coffee, RRs were 1.2 for less than 30 years or 1.4 for 30 years or more. Coffee-related RRs were higher in the older age group and in ex-smokers. Among 105 cases and 338 controls who had never smoked, RRs were 1.9 for one or two cups per day, 1.8 for three and 1.5 for four or more (trend not significant). A higher prevalence of coffee drinking among bladder cancer cases than controls was confirmed, with no clear dose-risk relation.

Work-related bladder cancer risks in male Japanese workers: estimation of attributable fraction and geographical correlation analysis

One hundred and forty-nine relative risks (RRs) on occupations and bladder cancer were extracted from 27 case-control studies and geometric means were calculated for 27 occupations as summary RRs. Those in high risk occupations, among whom the summary RRs significantly exceeded unity, were found to be petroleum workers (RR = 3.51), dye workers (RR = 3.38), machinists (RR = 2.76), drivers (RR = 2.22), rubber workers (RR = 2.19), printers (RR = 2.12), clothing/tailors (RR = 2.10), wood workers/carpenters (RR = 1.70), miners (RR = 1.68), textile workers (RR = 1.63), mechanics (RR = 1.54), engineers (RR = 1.54), leather workers (RR = 1.49), painters (RR = 1.48) and chemical workers (RR = 1.44). The estimated numbers of male bladder cancers in 1980 in the high risk and other occupations were 820 and 2065 cases, respectively. The estimated number of work-related bladder cancer was 548 cases, the attributable fraction being 19% in active employees and 12% in the entire population. The geographical distribution of male bladder cancer deaths in Japan was positively correlated with the distributions of workers in the transport/communications industry and in tertiary industries including services, wholesale, retail, finance and insurance, whereas it was negatively correlated with the distribution of workers in the agricultural industry. These findings suggest that workers in certain industries may be at high risk of bladder cancer, but lifestyle modification associated with urbanization and industrialization could be an alternative explanation.

Coffee consumption and bladder cancer risk

The relationship between coffee drinking and the risk of bladder cancer was analyzed within the framework of a French hospital-based case-control study conducted between 1984 and 1987, which included 690 cases of histologically confirmed bladder cancer (599 males and 91 females), and 690 age-, sex- and hospital-matched controls. To dissociate the effects of smoking and coffee drinking among males, the analysis of the male group was restricted to 2 contrasted subgroups: non-smokers on the one hand, and current smokers and inhalers of black tobacco cigarettes on the other. Coffee drinking was found to be significantly associated with the risk of bladder cancer among men in both groups and the increase in the risk was dose-dependent (OR = 1, 2.9, 5.1 respectively, for drinking 1, 2, greater than or equal to 3 cups of coffee per day among non-smokers, and 1, 2.5 and 3.0 respectively, for drinking 1-4, 5-7, greater than cups among smokers). This result was not observed for women.

Urothelial cancer and some industry-related chemicals: an evaluation of the epidemiologic literature

In a previous cohort study by our group, certain industry-related chemicals were judged as warranting further attention as possible urothelial carcinogens. In this paper, the epidemiologic literature of cancer of the lower urinary tract is evaluated for these substances. We would like to add combustion gases/soot from coal to the substances considered as increasing the risk of urothelial cancer. It is, however, uncertain whether this risk is due to contaminants of aromatic amines in tar volatiles or whether it depends on other agents, such as nitroarenes or polycyclic aromatic hydrocarbons. Furthermore, we find some support for the hypothesis that exposure to chlorinated aliphatic hydrocarbons increases the risk of urothelial cancer. For creosote, cutting fluids and cutting oils, hair dyes, and polychlorinated biphenyls, data are scarce. Available data do not support the hypothesis that asbestos is associated with urothelial cancer. "Publication bias," such that only limited information was available, was judged to be a potential problem in the review for many, but not all, of the substances investigated.

Tobacco smoking, coffee, cocoa and tea consumption in relation to mortality from urinary bladder cancer in Italy

This paper examines changes in mortality from urinary bladder cancer in Italy during the years 1950-81 in relation to changes in smoking habits and in coffee, cocoa and tea consumption. The authors found that, in both sexes and for all ages, mortality has been increasing throughout this period, although the rates and relative increase have consistently been much lower and more gradual for women than for men. From the analysis of age-cohort-period variation it seems that bladder cancer mortality can also be influenced by changes in smoking habit patterns and by variation in the quality of diagnoses. The increase in death risk for both sexes in Italy up to cohorts born around 1905-10 can be related to occupational exposures and to high-tar-content tobacco smoking, whereas the tendency for mortality rates to stabilize and decline in cohorts born after 1910 were influenced by changes from high-tar-content and no-filter cigarettes to low-tar-content and filter cigarettes and by prevention measures taken in at-risk working environments. The consumption of coffee, cocoa and tea does not seem to be related to the increase in bladder cancer risk in Italy.

Occupation and bladder cancer in Utah

The relationships between bladder cancer and occupation, industries, and occupational exposures in Utah were examined in a population-based, case-control study conducted between 1977 and 1983. Life-long occupational histories were obtained for 417 cases (332 men and 85 women) and 877 controls (685 men and 192 women). Although few positive findings emerged in this study, increased risks were detected among men for employment in the leather and textile industries which increased with duration of employment. The effects were most marked for employment beginning 45 or more years prior to interview (odds ratio [OR] for textiles = 1.92, confidence interval [CI] = 0.89-4.46; for leather OR = 2.95, CI = 0.63-13.76). Among men and women, increased risk was detected among clerical workers employed for less than 10 years (OR = 1.59, CI = 1.16-2.17) although the risk decreased with increased duration of employment (OR = 0.88, CI = 0.55-1.40 for greater than or equal to 10 years). A protective effect was seen among men and women for 10 or more years employment in professional, managerial, and technical occupations (OR = 0.68, CI = 0.50-0.92). Employment as a carpenter resulted in increased risk which increased with duration. Increased risk for bladder cancer was detected among carpenters who smoked but not among carpenters who never smoked. We used an occupation-exposure linkage system to identify workers exposed to aromatic amino compounds; such workers did not have increased risk of bladder cancer, although interaction between long-term exposure to aromatic amino compounds and smoking was detected. Interactions between smoking and other industrial or occupational exposures were not demonstrated, and for the most part, smoking did not confound the estimates of the bladder cancer-occupation relationships.

Occupational factors and the incidence of cancer of the bladder in Canada

During 1979-82, a case-control study of occupational factors and urinary bladder cancer was conducted in Edmonton, Calgary, Toronto, and Kingston, Canada. A total of 826 histologically verified cases of cancer were individually matched by sex, age, and area of residence to 792 randomly selected population controls. Subjects were specifically asked about employment in several industries thought relevant to risk of bladder cancer. Information was also obtained on lifelong occupational history, with special attention given regarding exposures to fumes, dusts, smoke, and chemicals. In addition, subjects provided data on past medical and residential history, on intake of certain dietary items, and on exposure to tobacco and other lifestyle factors. Conditional logistic regression methods were used for the analysis. Under adjustment for cumulative lifetime cigarette consumption, it appeared that for both men and women, most of the occupational factors examined were not associated with significant alteration in risk of bladder cancer. For exposures during the period eight to 28 years before diagnosis, however, raised risk was suggested for men employed at least six months in the chemicals industry (odds ratio = 2.37, p = 0.004), in dye manufacturing or the dyeing of cloth (OR = 3.62 and 4.63, p = 0.041 and 0.035, respectively), as tailors (OR = 3.85, p = 0.015), or in jobs in which contact with diesel or traffic fumes occurred (OR = 1.69, p = 0.0008). Increased risk was also seen for men occupationally exposed to tars or asphalt (OR = 3.11, p = 0.019). This study then, at least for men, supports perhaps a few of the suspect industries as related to risk of bladder cancer.