A pooled analysis of bladder cancer case-control studies evaluating smoking in men and women

Risk of urinary tract cancers following arsenic exposure and tobacco smoking: a review

Bladder cancer, prostate cancer, and kidney cancer, due to their high morbidity and mortality rates, result in significant economic and health care costs. Arsenic exposure affects the drinking water of millions of people worldwide. Long-term exposure to arsenic, even in low concentrations, increases the risk of developing various cancers. Smoking is also one of the leading causes of bladder, prostate and kidney cancers. Accordingly, this research reviews the relationship between arsenic exposure and smoking with three kinds of urinary tract cancers (bladder cancer, prostate cancer, and kidney cancer) due to their widespread concern for their negative impact on public health globally. In this review, we have gathered the most current information from scientific databases [PubMed, Scopus, Google Scholar, ISI web of science] regarding the relationship between arsenic exposure and tobacco smoking with the risk of bladder, prostate, and kidney cancer. In several studies, a significant relationship was determined between the incidence and mortality rate of the above-mentioned cancers in humans with arsenic exposure and tobacco smoking. The decrease or cessation of smoking and consumption of arsenic-free water significantly declined the incidence of bladder, prostate, and kidney cancers.

Photodynamic versus white-light-guided resection of first-diagnosis non-muscle-invasive bladder cancer: PHOTO RCT

BACKGROUND

Around 7500 people are diagnosed with non-muscle-invasive bladder cancer in the UK annually. Recurrence following transurethral resection of bladder tumour is common, and the intensive monitoring schedule required after initial treatment has associated costs for patients and the NHS. In photodynamic diagnosis, before transurethral resection of bladder tumour, a photosensitiser that is preferentially absorbed by tumour cells is instilled intravesically. Transurethral resection of bladder tumour is then conducted under blue light, causing the photosensitiser to fluoresce. Photodynamic diagnosis-guided transurethral resection of bladder tumour offers better diagnostic accuracy than standard white-light-guided transurethral resection of bladder tumour, potentially reducing the chance of subsequent recurrence.

OBJECTIVE

The objective was to assess the clinical effectiveness and cost-effectiveness of photodynamic diagnosis-guided transurethral resection of bladder tumour.

DESIGN

This was a multicentre, pragmatic, open-label, parallel-group, non-masked, superiority randomised controlled trial. Allocation was by remote web-based service, using a 1 : 1 ratio and a minimisation algorithm balanced by centre and sex.

SETTING

The setting was 22 NHS hospitals.

PARTICIPANTS

Patients aged ≥ 16 years with a suspected first diagnosis of high-risk non-muscle-invasive bladder cancer, no contraindications to photodynamic diagnosis and written informed consent were eligible.

INTERVENTIONS

Photodynamic diagnosis-guided transurethral resection of bladder tumour and standard white-light cystoscopy transurethral resection of bladder tumour.

MAIN OUTCOME MEASURES

The primary clinical outcome measure was the time to recurrence from the date of randomisation to the date of pathologically proven first recurrence (or intercurrent bladder cancer death). The primary health economic outcome was the incremental cost per quality-adjusted life-year gained at 3 years.

RESULTS

We enrolled 538 participants from 22 UK hospitals between 11 November 2014 and 6 February 2018. Of these, 269 were allocated to photodynamic diagnosis and 269 were allocated to white light. A total of 112 participants were excluded from the analysis because of ineligibility (n = 5), lack of non-muscle-invasive bladder cancer diagnosis following transurethral resection of bladder tumour (n = 89) or early cystectomy (n = 18). In total, 209 photodynamic diagnosis and 217 white-light participants were included in the clinical end-point analysis population. All randomised participants were included in the cost-effectiveness analysis. Over a median follow-up period of 21 months for the photodynamic diagnosis group and 22 months for the white-light group, there were 86 recurrences (3-year recurrence-free survival rate 57.8%, 95% confidence interval 50.7% to 64.2%) in the photodynamic diagnosis group and 84 recurrences (3-year recurrence-free survival rate 61.6%, 95% confidence interval 54.7% to 67.8%) in the white-light group (hazard ratio 0.94, 95% confidence interval 0.69 to 1.28; p = 0.70). Adverse event frequency was low and similar in both groups [12 (5.7%) in the photodynamic diagnosis group vs. 12 (5.5%) in the white-light group]. At 3 years, the total cost was £12,881 for photodynamic diagnosis-guided transurethral resection of bladder tumour and £12,005 for white light. There was no evidence of differences in the use of health services or total cost at 3 years. At 3 years, the quality-adjusted life-years gain was 2.094 in the photodynamic diagnosis transurethral resection of bladder tumour group and 2.087 in the white light group. The probability that photodynamic diagnosis-guided transurethral resection of bladder tumour was cost-effective was never > 30% over the range of society's cost-effectiveness thresholds.

LIMITATIONS

Fewer patients than anticipated were correctly diagnosed with intermediate- to high-risk non-muscle-invasive bladder cancer before transurethral resection of bladder tumour and the ratio of intermediate- to high-risk non-muscle-invasive bladder cancer was higher than expected, reducing the number of observed recurrences and the statistical power.

CONCLUSIONS

Photodynamic diagnosis-guided transurethral resection of bladder tumour did not reduce recurrences, nor was it likely to be cost-effective compared with white light at 3 years. Photodynamic diagnosis-guided transurethral resection of bladder tumour is not supported in the management of primary intermediate- to high-risk non-muscle-invasive bladder cancer.

FUTURE WORK

Further work should include the modelling of appropriate surveillance schedules and exploring predictive and prognostic biomarkers.

TRIAL REGISTRATION

This trial is registered as ISRCTN84013636.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 40. See the NIHR Journals Library website for further project information.

Expression pattern of p53-binding protein 1 as a new molecular indicator of genomic instability in bladder urothelial carcinoma

Copy number alterations and loss of heterozygosity are associated with increasing tumor grade and bladder cancer stage. Our previous study suggested that co-expression of Ki-67 and p53-binding protein 1 (53BP1) could provide an indicator of an abnormal DNA damage response (DDR) pathway. The present study investigated 53BP1 expression as a novel molecular marker in urothelial carcinoma (UC) using bladder tissues with in total of 40 cases including a normal urothelium, urothelial papilloma, low-grade UC, or high-grade UC. Double-label immunofluorescence was used to analyze 53BP1 and Ki-67 expression. This was compared with the level of chromosomal instability and with the expression of other DDR molecules catalytic subunit. This study identified clear differences in the 53BP1 expression patterns in urothelial carcinogenesis, and their close association with genomic instability. 53BP1 abnormal immunoreactivity, particularly with co-localization of Ki-67, was restricted to malignant tissues. Our analyses indicated that a cut-off of >4% of nuclei with 53BP1 abnormal expression plus Ki-67 immunoreactivity distinguished high-grade UC from low-grade UC with 80.0% sensitivity and 100% specificity. We therefore propose that double immunofluorescent analysis of 53BP1 and Ki-67 expression could provide a useful tool to estimate the chromosomal instability and malignant potential of urothelial tumors.

Modifiable risk factors for the prevention of bladder cancer: a systematic review of meta-analyses

Each year, 430,000 people are diagnosed with bladder cancer. Due to the high recurrence rate of the disease, primary prevention is paramount. Therefore, we reviewed all meta-analyses on modifiable risk factors of primary bladder cancer. PubMed, Embase and Cochrane database were systematically searched for meta-analyses on modifiable risk factors published between 1995 and 2015. When appropriate, meta-analyses (MA) were combined in meta-meta-analysis (MMA). If not, the most comprehensive MA was selected based on the number of primary studies included. Probability of causation was calculated for individual factors and a subset of lifestyle factors combined. Of 1496 articles identified, 5 were combined in MMA and 21 were most comprehensive on a single risk factor. Statistically significant associations were found for current (RR 3.14) or former (RR 1.83) cigarette smoking, pipe (RR 1.9) or cigar (RR 2.3) smoking, antioxidant supplementation (RR 1.52), obesity (RR 1.10), higher physical activity levels (RR 0.86), higher body levels of selenium (RR 0.61) and vitamin D (RR 0.75), and higher intakes of: processed meat (RR 1.22), vitamin A (RR 0.82), vitamin E (RR 0.82), folate (RR 0.84), fruit (RR 0.77), vegetables (RR 0.83), citrus fruit (RR 0.85), and cruciferous vegetables (RR 0.84). Finally, three occupations with the highest risk were tobacco workers (RR 1.72), dye workers (RR 1.58), and chimney sweeps (RR 1.53). The probability of causation for individual factors ranged from 4 to 68 %. The combined probability of causation was 81.8 %. Modification of lifestyle and occupational exposures can considerably reduce the bladder cancer burden. While smoking remains one of the key risk factors, also several diet-related and occupational factors are very relevant.

Combined effects of GSTO1 and SULT1A1 polymorphisms and cigarette smoking on urothelial carcinoma risk in a Taiwanese population

BACKGROUND/PURPOSE

Cigarette smoking is the main risk factor for urothelial carcinoma of the bladder (UCB). Glutathione S-transferase omega 1 (GSTO1) and sulfotransferase 1A1 (SULT1A1) have been reported to be associated with the metabolism of polycyclic aromatic hydrocarbons (PAHs) and aromatic amines. The aim of the present study was to investigate the combined effects of polymorphisms in GSTO1 and SULT1A1 genes and cigarette smoking on UCB risk in a Taiwanese population.

METHODS

A total of 300 patients with histopathologically confirmed UCB and 233 cancer-free controls were recruited from the Department of Urology of Tung's Taichung Metro Harbor Hospital and Taipei Medical University Hospital. A comprehensive interview was conducted to collect personal information, including demographic characteristics and cigarette smoking status. A multivariate-adjusted logistic regression was performed to estimate the risk of UCB.

RESULTS

A significantly increased risk of UCB was observed in ever smokers [odds ratio (OR) = 2.3]. The Ala/Ala genotype of the GSTO1 gene and the Arg/Arg genotype of the SULT1A1 gene were associated with a significantly increased risk of UCB, with ORs of 1.8 [95% confidence interval (CI) = 1.2-2.6] and 2.1 (95% CI = 1.6-4.5), respectively. Significantly increased UCB risks were found in heavy smokers with the Ala/Ala genotype of the GSTO1 gene (OR = 4.2) and the Arg/Arg genotype of the SULT1A1 gene (OR = 6.8). Furthermore, a significant synergistic effect in an additive model (OR = 3.5) between the GSTO1 Ala/Ala genotype and the SULT1A1 Arg/Arg genotype on UCB risk was observed.

CONCLUSION

The present study provided epidemiological evidence for a significantly increased risk of UCB in ever smokers with the Ala/Ala genotype of the GSTO1 gene and the Arg/Arg genotype of the SULT1A1 gene.

The role of the urologist in smoking cessation: why is it important?

INTRODUCTION

Tobacco use is the most preventable cause of death in the world today. Smoking is a well-known risk factor for various cancers, including urothelial carcinoma, and bladder cancer (BCa) is a leading global cause of cancer mortality in men.

OBJECTIVE

To review the epidemiology of BCa as a tobacco-related disease, the association between smoking and BCa risk, and the potential smoking cessation interventions that urologists can perform in their medical practice.

METHODS

A search of recent literature was conducted using the MEDLINE database and the Internet, as well as resources from well-known health, cancer, and tobacco control organizations.

RESULTS

Smoking is well described as a risk factor of BCa. The risk correlates with the number of cigarettes smoked daily and the duration of smoking. Moreover, smoking worsens BCa treatment outcomes and prognosis. However, smoking cessation substantially prolongs life at every stage, and brief medical interventions can be performed by urologists that can result in the patient ceasing to smoke. Patient education is critical, especially if the patient is unaware that smoking increases the risk of BCa.

CONCLUSION

Urologists may play an essential role in helping their patients cease smoking, subsequently decreasing the smoking-related risk of BCa. Their cessation efforts should be focused on brief interventions and collaboration with specialized smoking cessation resources.

Duration and intensity of tobacco smoking and the risk of papillary and non-papillary transitional cell carcinoma of the bladder

PURPOSE

To evaluate the impact of tobacco smoking on specific histological subtypes of transitional cell carcinoma of the bladder (TCC).

METHODS

Between 2003 and 2009, we conducted a hospital-based case-control study in Italy, enrolling 531 incident TCC cases and 524 cancer-free matched patients. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated through multiple logistic regression models.

RESULTS

Compared to never smokers, TCC risk was threefold higher in former smokers (95% CI 2.07-4.18) and more than sixfold higher in current smokers (95% CI 4.54-9.85). TCC risk steadily increased with increasing intensity (OR for ≥25 cigarettes/day 8.75; 95% CI 3.40-22.55) and duration of smoking (OR for ≥50 years 5.46; 95% CI 2.60-11.49). No heterogeneity emerged between papillary and non-papillary TCCs for smoking intensity and duration, but the risk for those who had smoked for ≥50 years was twice for non-papillary TCC (OR 10.88) compared with papillary one (OR 4.76). Among current smokers, the risk for a 10-year increase in duration grew across strata of intensity (p-trend = 0.046). Conversely, the risk for a 5-cigarette/day increase in smoking intensity was quite steady across strata of duration (p-trend = 0.18).

CONCLUSIONS

Study results suggested that duration of smoking outweighs intensity in determining TCC risk, with limited differences across histological subtypes. Elimination of tobacco smoking may prevent about 65 % of TCCs.

Arsenic exposure and bladder cancer: quantitative assessment of studies in human populations to detect risks at low doses

While exposures to high levels of arsenic in drinking water are associated with excess cancer risk (e.g., skin, bladder, and lung), exposures at lower levels (e.g., <100-200 µg/L) generally are not. Lack of significant associations may result from methodological issues (e.g., inadequate statistical power, exposure misclassification), or a different dose-response relationship at low exposures, possibly associated with a toxicological mode of action that requires a sufficient dose for increased tumor formation. The extent to which bladder cancer risk for low-level arsenic exposure can be statistically measured by epidemiological studies was examined using an updated meta-analysis of bladder cancer risk with data from two new publications. The summary relative risk estimate (SRRE) for all nine studies was elevated slightly, but not significantly (1.07; 95% confidence interval [CI]: 0.95-1.21, p-Heterogeneity [p-H]=0.543). The SRRE among never smokers was 0.85 (95% CI: 0.66-1.08, p-H=0.915), whereas the SRRE was positive and more heterogeneous among ever smokers (1.18; 95% CI: 0.97-1.44, p-H=0.034). The SRRE was statistically significantly lower than relative risks predicted for never smokers in the United States based on linear extrapolation of risks from higher doses in southwest Taiwan to arsenic water exposures >10 µg/L for more than one-third of a lifetime. By contrast, for all study subjects, relative risks predicted for one-half of lifetime exposure to 50 µg/L were just above the upper 95% CI on the SRRE. Thus, results from low-exposure studies, particularly for never smokers, were statistically inconsistent with predicted risk based on high-dose extrapolation. Additional studies that better characterize tobacco use and stratify analyses of arsenic and bladder cancer by smoking status are necessary to further examine risks of arsenic exposure for smokers.

Bladder cancer in Spain 2011: population based study

PURPOSE

We estimate the annual incidence of bladder cancer in Spain and describe the clinical profile of patients with bladder cancer enrolled in a population based study.

MATERIALS AND METHODS

Using the structure of the Spanish National Health System as a basis, in 2011 the AEU (Spanish Association of Urology) conducted this study with a representative sample from 26 public hospitals and a reference population of 10,146,534 inhabitants, comprising 21.5% of the Spanish population.

RESULTS

A total of 4,285 episodes of bladder cancer were diagnosed, of which 2,476 (57.8%) were new cases and 1,809 (42.2%) were cases of recurrence, representing an estimated 11,539 new diagnoses annually in Spain. The incidence of bladder cancer in Spain, age adjusted to the standard European population, was 20.08 cases per 100,000 inhabitants (95% CI 13.9, 26.3). Of patients diagnosed with a first episode of bladder cancer 84.3% were male, generally older than 59 years (81.7%) with a mean ± SD age of 70.5 ± 11.4 years. Of these patients 87.5% presented with some type of clinical symptom, with macroscopic hematuria (90.8%) being the most commonly detected. The majority of primary tumors were nonmuscle invasive (76.7%) but included a high proportion of high grade tumors (43.7%). According to the ISUP (International Society of Urologic Pathology)/WHO (2004) classification 51.1% was papillary high grade carcinoma. Carcinoma in situ was found in 2.2% of primary and 5.8% of recurrent cases.

CONCLUSIONS

The incidence of bladder cancer in Spain, age adjusted to the standard European population, confirms that Spain has one of the highest incidences in Europe. Most primary nonmuscle invasive bladder cancer corresponded to high risk patients but with a low detected incidence of carcinoma in situ.

Distinct SNP combinations confer susceptibility to urinary bladder cancer in smokers and non-smokers

Recently, genome-wide association studies have identified and validated genetic variations associated with urinary bladder cancer (UBC). However, it is still unknown whether the high-risk alleles of several SNPs interact with one another, leading to an even higher disease risk. Additionally, there is no information available on how the UBC risk due to these SNPs compare to the risk of cigarette smoking and to occupational exposure to urinary bladder carcinogens, and whether the same or different SNP combinations are relevant in smokers and non-smokers. To address these questions, we analyzed the genotypes of six SNPs, previously found to be associated with UBC, together with the GSTM1 deletion, in 1,595 UBC cases and 1,760 controls, stratified for smoking habits. We identified the strongest interactions of different orders and tested the stability of their effect by bootstrapping. We found that different SNP combinations were relevant in smokers and non-smokers. In smokers, polymorphisms involved in detoxification of cigarette smoke carcinogens were most relevant (GSTM1, rs11892031), in contrast to those in non-smokers with MYC and APOBEC3A near polymorphisms (rs9642880, rs1014971) being the most influential. Stable combinations of up to three high-risk alleles resulted in higher odds ratios (OR) than the individual SNPs, although the interaction effect was less than additive. The highest stable combination effects resulted in an OR of about 2.0, which is still lower than the ORs of cigarette smoking (here, current smokers' OR: 3.28) and comparable to occupational carcinogen exposure risks which, depending on the workplace, show mostly ORs up to 2.0.

Best practice in the treatment of nonmuscle invasive bladder cancer

Bladder carcinoma is the most common malignancy of the urinary tract. Approximately 75-85% of patients with bladder cancer present with a disease that is confined to the mucosa (stage Ta, carcinoma in situ) or submucosa (stage T1). These categories are grouped as nonmuscle invasive bladder cancer (NMIBC). Although the management of NMIBC tumours has significantly improved during the past few years, it remains difficult to predict the heterogeneous outcome of such tumours, especially if high-grade NMIBC is present. Transurethral resection is the initial treatment of choice for NMIBC. However, the high rates of recurrence and significant risk of progression in higher-grade tumours mandate additional therapy with intravesical agents. We discuss the role of various intravesical agents currently in use, including the immunomodulating agent bacillus Calmette-Guérin (BCG) and chemotherapeutic agents. We also discuss the current guidelines and the role of these therapeutic agents in the context of higher-grade Ta and T1 tumours. Beyond the epidemiology, this article focuses on the risk factors, classification and diagnosis, the prediction of recurrence and progression in NMIBC, and the treatments advocated for this invasive disease.

Impact of a bladder cancer diagnosis on smoking behavior

PURPOSE

Bladder cancer is the second most common tobacco-related malignancy. A new bladder cancer diagnosis may be an opportunity to imprint smoking cessation. Little is known about the impact of a diagnosis of bladder cancer on patterns of tobacco use and smoking cessation among patients with incident bladder cancer.

PATIENTS AND METHODS

A simple random sample of noninvasive bladder cancer survivors diagnosed in 2006 was obtained from the California Cancer Registry. Respondents completed a survey on history of tobacco use, beliefs regarding bladder cancer risk factors, and physician influence on tobacco cessation. Respondents were compared by smoking status. Those respondents smoking at diagnosis were compared with general population controls obtained from the California Tobacco Survey to determine the impact of a diagnosis of bladder cancer on patterns of tobacco use.

RESULTS

The response rate was 70% (344 of 492 eligible participants). Most respondents (74%) had a history of cigarette use. Seventeen percent of all respondents were smoking at diagnosis. Smokers with a new diagnosis of bladder cancer were almost five times as likely to quit smoking as smokers in the general population (48% v 10%, respectively; P < .001). The bladder cancer diagnosis and the advice of the urologist were the reasons cited most often for cessation. Respondents were more likely to endorse smoking as a risk factor for bladder cancer when the urologist was the source of their understanding.

CONCLUSION

The diagnosis of bladder cancer is an opportunity for smoking cessation. Urologists can play an integral role in affecting the patterns of tobacco use of those newly diagnosed.

Urothelial Carcinoma of the Urinary Bladder in Young Adults: Presentation, Clinical behavior and Outcome

Introduction. There is not much evidence regarding clinical behavior of bladder cancer in younger patients. We evaluated clinical characteristics, tumor recurrence and progression in patients younger than 40 years old with urothelial bladder carcinoma. Methods. We retrospectively reviewed the medical records of 31 patients less than 40 years old who were firstly managed with bladder urothelial carcinoma in our department. Data were analysed with the Chi-square test. Results. Mean age was 31.7 years. Mean followup was 38.52 months (11–72 months). Nineteen (61%) patients were diagnosed with GII and 2 (6%) patients with GIII disease. Five (16%) patients presented with T1 disease. Three (9%) patients with invasive disease underwent cystectomy and adjuvant chemotherapy and one developed metastatic disease. Ten (32%) patients recurred during followup with a disease free recurrence rate of 65% the first 2 years after surgery. From those, 1 patient progressed to higher stage and three to higher grade disease. No patient died during followup. Conclusions. Bladder urothelial carcinoma in patients younger than 40 years is usually low stage and low grade. Management of these patients should be according to clinical characteristics and no different from older patients with the same disease.

An examination of male and female odds ratios by BMI, cigarette smoking, and alcohol consumption for cancers of the oral cavity, pharynx, and larynx in pooled data from 15 case-control studies

BACKGROUND

Greater tobacco smoking and alcohol consumption and lower body mass index (BMI) increase odds ratios (OR) for oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancers; however, there are no comprehensive sex-specific comparisons of ORs for these factors.

METHODS

We analyzed 2,441 oral cavity (925 women and 1,516 men), 2,297 oropharynx (564 women and 1,733 men), 508 hypopharynx (96 women and 412 men), and 1,740 larynx (237 women and 1,503 men) cases from the INHANCE consortium of 15 head and neck cancer case-control studies. Controls numbered from 7,604 to 13,829 subjects, depending on analysis. Analyses fitted linear-exponential excess ORs models.

RESULTS

ORs were increased in underweight (< 18.5 BMI) relative to normal weight (18.5-24.9) and reduced in overweight and obese categories (≥ 25 BMI) for all sites and were homogeneous by sex. ORs by smoking and drinking in women compared with men were significantly greater for oropharyngeal cancer (p < 0.01 for both factors), suggestive for hypopharyngeal cancer (p = 0.05 and p = 0.06, respectively), but homogeneous for oral cavity (p = 0.56 and p = 0.64) and laryngeal (p = 0.18 and p = 0.72) cancers.

CONCLUSIONS

The extent that OR modifications of smoking and drinking by sex for oropharyngeal and, possibly, hypopharyngeal cancers represent true associations, or derive from unmeasured confounders or unobserved sex-related disease subtypes (e.g., human papillomavirus-positive oropharyngeal cancer) remains to be clarified.

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

CONTEXT

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

OBJECTIVE

To evaluate the association between tobacco smoking and bladder cancer.

DESIGN, SETTING, AND PARTICIPANTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

Lifetime exposure to arsenic in drinking water and bladder cancer: a population-based case-control study in Michigan, USA

OBJECTIVE

Arsenic in drinking water has been linked with the risk of urinary bladder cancer, but the dose-response relationships for arsenic exposures below 100 microg/L remain equivocal. We conducted a population-based case-control study in southeastern Michigan, USA, where approximately 230,000 people were exposed to arsenic concentrations between 10 and 100 microg/L.

METHODS

This study included 411 bladder cancer cases diagnosed between 2000 and 2004, and 566 controls recruited during the same period. Individual lifetime exposure profiles were reconstructed, and residential water source histories, water consumption practices, and water arsenic measurements or modeled estimates were determined at all residences. Arsenic exposure was estimated for 99% of participants' person-years.

RESULTS

Overall, an increase in bladder cancer risk was not found for time-weighted average lifetime arsenic exposure >10 microg/L when compared with a reference group exposed to <1 microg/L (odds ratio (OR) = 1.10; 95% confidence interval (CI): 0.65, 1.86). Among ever-smokers, risks from arsenic exposure >10 microg/L were similarly not elevated when compared to the reference group (OR = 0.94; 95% CI: 0.50, 1.78).

CONCLUSIONS

We did not find persuasive evidence of an association between low-level arsenic exposure and bladder cancer. Selecting the appropriate exposure metric needs to be thoughtfully considered when investigating risk from low-level arsenic exposure.

New Italian guidelines on bladder cancer, based on the World Health Organization 2004 classification

OBJECTIVE To provide evidence-based recommendations on bladder cancer management METHODS A multidisciplinary guideline panel composed of urologists, medical oncologists, radiotherapists, general practitioners, radiologists, epidemiologists and methodologists conducted a structured review of previous reports, searching the Medline database from 1 January 2004 to 31 December 2008. The milestone papers published before January 2004 were accepted for analysis. The level of evidence and the grade of the recommendations were established using the GRADE system. RESULTS In all, 15 806 references were identified, 1940 retrieved, 1712 eliminated (specifying the reason for their elimination) and 971 included in the analysis, as well as 241 milestone reports. A consensus conference held to discuss the discrepancies between the scientific evidence and the clinical practice was then attended by 122 delegates of various specialities. CONCLUSION Recommendations on bladder cancer management are provided.

Meta-analyses of occupational exposure as a painter and lung and bladder cancer morbidity and mortality 1950-2008

The International Agency for Research on Cancer (IARC) classified occupational painting as a human carcinogen based on lung and bladder cancers; however, no specific exposures were implicated. The authors conducted comprehensive meta-analyses of the epidemiological literature on occupational painting and these cancers. The authors abstracted study results and confounder information, and used quantile plots and regression models to evaluate heterogeneity and publication bias. Summary risk estimates were derived and sensitivity analyses performed to evaluate smoking, socioeconomic status (SES), and exposure variables. Where applicable, a Bayesian approach was used to externally adjust for smoking, a major risk factor for both cancers. For lung cancer cohort mortality studies, publication bias and heterogeneity were seen, and earlier studies reported higher risk estimates than later studies. Overall lung cancer summary risk estimates were 1.29 for case-control and 1.22 and 1.36 for cohort morbidity and mortality studies, respectively, and risk estimates for bladder cancer were 1.28 for case-control and 1.14 and 1.27 for cohort morbidity and mortality studies, respectively (all statistically significant). Risks did not differ between painters and mixed occupations. Nonsignificant summary estimates resulted for lung and bladder cancers when controlling for SES, or externally adjusting for smoking in lung cancer studies. Summary risks varied by control source for case-control studies. Residual confounding by smoking and SES, lack of exposure group effect, and publication bias limit the ability of the meta-analyses to explain associations observed between occupational painting and lung and bladder cancers. Given the long latencies for lung and bladder cancers, these weak associations, if real, may not be elucidated through studies of occupational painting today.

Molecular epidemiology of DNA repair genes in bladder cancer

Bladder cancer is a common disease, whose major risk factors include smoking and occupational exposure to chemicals. Superficial bladder cancer has significant healthcare cost implications due to the need for repeated cystoscopic surveillance. Chemical carcinogens can undergo metabolic activation and detoxification in the liver and polymorphisms in the relevant genes have been shown to be associated with bladder cancer risk. In addition, DNA repair enzymes are required to repair the DNA damage associated with carcinogen exposure. The main pathways involved are nucleotide excision repair, base excision repair, and double strand break repair. Investigation of individual polymorphisms in DNA repair genes in bladder cancer has yielded few robust positive findings, which is not surprising given the multifactorial nature of the disease. Pathway approaches using novel genotyping technologies will allow more comprehensive studies of multiple polymorphisms in multiple genes. It will also be possible to investigate gene-environment interaction more rigorously than heretofore, using novel statistical methodology, in larger studies and through collaborative efforts within consortia. The results of the genome-wide association studies in bladder cancer are awaited with interest. In the future, genetic tests might be used in the prevention of bladder cancer to encourage lifestyle changes in those at highest risk of developing the disease, and in the treatment of bladder cancer to optimise cure rates whilst minimising morbidity in a cost-effective manner.

Tobacco smoking and cancer: a meta-analysis

We conducted a systematic meta-analysis of observational studies on cigarette smoking and cancer from 1961 to 2003. The aim was to quantify the risk for 13 cancer sites, recognized to be related to tobacco smoking by the International Agency for Research on Cancer (IARC), and to analyze the risk variation for each site in a systematic manner. We extracted data from 254 reports published between 1961 and 2003 (177 case-control studies, 75 cohorts and 2 nested case-control studies) included in the 2004 IARC Monograph on Tobacco Smoke and Involuntary Smoking. The analyses were carried out on 216 studies with reported estimates for 'current' and/or 'former' smokers. We performed sensitivity analysis, and looked for publication and other types of bias. Lung (RR = 8.96; 95% CI: 6.73-12.11), laryngeal (RR = 6.98; 95% CI: 3.14-15.52) and pharyngeal (RR = 6.76; 95% CI: 2.86-15.98) cancers presented the highest relative risks (RRs) for current smokers, followed by upper digestive tract (RR = 3.57; 95% CI: 2.63-4.84) and oral (RR = 3.43; 95% CI: 2.37-4.94) cancers. As expected, pooled RRs for respiratory cancers were greater than the pooled estimates for other sites. The analysis of heterogeneity showed that study type, gender and adjustment for confounding factors significantly influence the RRs estimates and the reliability of the studies.

Smoking and bladder cancer in Spain: effects of tobacco type, timing, environmental tobacco smoke, and gender

We examined the effects of dose, type of tobacco, cessation, inhalation, and environmental tobacco smoke exposure on bladder cancer risk among 1,219 patients with newly diagnosed bladder cancer and 1,271 controls recruited from 18 hospitals in Spain. We used unconditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for the association between bladder cancer risk and various characteristics of cigarette smoking. Current smokers (men: OR, 7.4; 95% CI, 5.3-10.4; women: OR, 5.1; 95% CI, 1.6-16.4) and former smokers (men: OR, 3.8; 95% CI, 2.8-5.3; women: OR, 1.8; 95% CI, 0.5-7.2) had significantly increased risks of bladder cancer compared with nonsmokers. We observed a significant positive trend in risk with increasing duration and amount smoked. After adjustment for duration, risk was only 40% higher in smokers of black tobacco than that in smokers of blond tobacco (OR, 1.4; 95% CI, 0.98-2.0). Compared with risk in current smokers, a significant inverse trend in risk with increasing time since quitting smoking blond tobacco was observed (> or =20 years cessation: OR, 0.2; 95% CI, 0.1-0.9). No trend in risk with cessation of smoking black tobacco was apparent. Compared with men who inhaled into the mouth, risk increased for men who inhaled into the throat (OR, 1.7; 95% CI, 1.1-2.6) and chest (OR, 1.5; 95% CI, 1.1-2.1). Cumulative occupational exposure to environmental tobacco smoke seemed to confer increased risk among female nonsmokers but not among male nonsmokers. After eliminating the effect of cigarette smoking on bladder cancer risk in our study population, the male-to-female incidence ratio decreased from 8.2 to 1.7, suggesting that nearly the entire male excess of bladder cancer observed in Spain is explained by cigarette smoking rather than occupational/environmental exposures to other bladder carcinogens.