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

Association of body mass index with bladder cancer risk in men depends on abdominal obesity

PURPOSE

The previous epidemiological studies about the associations between obesity and bladder cancer risk have reported inconsistent results. Therefore, we analyzed whether the abdominal obesity effected on the risk of developing bladder cancer according to body mass index (BMI) using nationally representative data from the National Health Insurance System (NHIS).

PATIENTS AND METHODS

Among people who underwent at least one health examination from 2009 to 2012 in Korea, 11,823,876 men without a previous diagnosis of bladder cancer were followed up until December 2015. Multiple Cox regression analysis was conducted to determine the hazard ratio (HR) and 95% confidence interval (CI) for the association between bladder cancer and BMI or waist circumference (WC).

RESULTS

Significant upward trends in the risk of bladder cancer were observed with increasing BMI or WC according to the multivariate-adjusted model. However, the association between BMI and bladder cancer is influenced by the presence of abdominal obesity. In the group with WC < 90 cm, there was no significant change in the HRs for bladder cancer development beyond the reference BMI. In contrast, the HRs for bladder cancer showed statistically significant increase as the BMI increased beyond the reference BMI in the group with WC ≥ 90 cm.

CONCLUSION

This population-based study showed that increasing BMI and increasing WC were risk factors for developing bladder cancer in men, independent of confounding variables. However, there was a discrepancy in the trend of bladder cancer development according to BMI between the groups with abdominal obesity and without abdominal obesity.

Body mass index modifies bladder cancer risk associated with low estrogen exposure among Egyptian women after menopause

PURPOSE

Investigators have reported inconsistent findings regarding associations between body mass index (BMI) and bladder cancer risk, and they have postulated that sex steroids mediate such associations. We assessed the impact of BMI on the relationship between bladder cancer risk and combinations of age at first childbirth, parity, and age at menopause, among Egyptian women.

METHODS

We used data from our multicenter case-control study of 419 cases and 786 controls in logistic regression models to estimate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of such associations.

RESULTS

Age > 18 years at first childbirth and parity ≤ 6 were significantly associated with bladder cancer risk, which was higher when both factors (AOR = 2.31, 95% CI = 1.55-3.43) and age at menopause < 45 years (AOR = 3.51, 95% CI = 1.88-6.55) were present. Early menopause was associated with higher bladder cancer risk in obese (AOR = 2.90, 95% CI = 1.40-5.98) but not normal weight women (AOR = 0.98, 95% CI = 0.58-1.65; P_interaction = 0.11), and the risk was greatest when both first childbirth at age > 18 years and parity ≤ 6 were present (AOR = 7.60, 95% CI = 1.84-31.35); however, overweight and obesity were associated with significantly lower bladder cancer risk (AOR = 0.59, 95% CI = 0.43-0.81, and AOR = 0.26, 95% CI = 0.18-0.38, respectively).

CONCLUSION

Body mass index appears to modify bladder cancer risk in Egyptian women after menopause by slightly enhancing the risk associated with low estrogen exposure among the obese only. Longitudinal studies of the BMI role in bladder malignancy in this distinctive population are required.

Trends in the incidence and mortality of transitional cell carcinoma of the bladder for the last four decades in the USA: a SEER-based analysis

BACKGROUND

Transitional cell carcinoma (TCC) accounts for around 95% of bladder cancers and is the 4th most common cancer among men and the tenth most common in women, in the US. There is a constant need to clarify current TCC incidence and mortality rates among different population groups for better clinical practice guidelines. We aimed to describe the TCC incidence and incidence-based mortality by demographic and tumor-related characteristics over the last 40 years in the US.

METHODS

We obtained data from the SEER 18 registries to study TCC cases that were diagnosed between the years 1973 and 2014. We calculated incidence rates and incidence-based mortality rates in different demographic and tumor-related characteristics and expressed rates by 100,000 person-years. We then calculated the annual changes in incidence and incidence-based mortality rates and displayed them as annual percent changes (APCs).

RESULTS

There were 182,114 patients with TCC between 1973 and 2014 in the United States. Overall incidence rates of TCC increased 0.16% (95% CI, 0.02-0.30, p = .02) per year over the study period. However, the incidence declined significantly since 2007; (95%CI,-1.89- -0.77, p < .001), except among the elderly and African Americans, which increased significantly over the study period. Overall TCC mortality rates did not change over the study period. However, since 2000 it started to decrease significantly.

CONCLUSION

TCC incidence and incidence-based mortality rates had been showing significant increases over the previous decades. However, significant declines in both incidence and incidence-based mortality rates have been observed over the recent years, except in some patients with certain racial groups. Improved understanding of the etiological and ecological factors of TCC could lead to further declines in incidence and incidence-based mortality rates.

Epidemiology of Bladder Cancer: A Systematic Review and Contemporary Update of Risk Factors in 2018

CONTEXT

Bladder cancer (BC) is a significant health problem, and understanding the risk factors for this disease could improve prevention and early detection.

OBJECTIVE

To provide a systematic review and summary of novel developments in epidemiology and risk factors for BC.

EVIDENCE ACQUISITION

A systematic review of original articles was performed by two pairs of reviewers (M.G.C., I.J., F.E., and K.P.) using PubMed/Medline in December 2017, updated in April 2018. To address our primary objective of reporting contemporary studies, we restricted our search to include studies from the last 5yr. We subdivided our review according to specific risk factors (PICO [Population Intervention Comparator Outcome]).

EVIDENCE SYNTHESIS

Our search found 2191 articles, of which 279 full-text manuscripts were included. We separated our manuscripts by the specific risk factor they addressed (PICO). According to GLOBOCAN estimates, there were 430000 new BC cases and 165000 deaths worldwide in 2012. Tobacco smoking and occupational exposure to carcinogens remain the factors with the highest attributable risk. The literature was limited by heterogeneity of data.

CONCLUSIONS

Evidence is emerging regarding gene-environment interactions, particularly for tobacco and occupational exposures. In some populations, incidence rates are declining, which may reflect a decrease in smoking. Standardisation of reporting may help improve epidemiologic evaluation of risk.

PATIENT SUMMARY

Bladder cancer is common worldwide, and the main risk factors are tobacco smoking and exposure to certain chemicals in the working and general environments. There is ongoing research to identify and reduce risk factors, as well as to understand the impact of genetics on bladder cancer risk.

The Adenosine Monophosphate (AMP) Analog, 5-Aminoimidazole-4-Carboxamide Ribonucleotide (AICAR) Inhibits Hepatosteatosis and Liver Tumorigenesis in a High-Fat Diet Murine Model Treated with Diethylnitrosamine (DEN)

Background

The development and progression of hepatocellular carcinoma (HCC) are associated with obesity and hepatosteatosis. AMP-activated protein kinase (AMPK) regulates metabolic homeostasis. This study aimed to investigate the effects of treatment with the adenosine monophosphate (AMP) analog, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) on hepatosteatosis in a mouse model fed a high-fat diet (HFD), and on hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN) in the HFD mouse model.

Material/Methods

Male C57BL/6 male mice from two weeks of age were fed a high-fat diet, resulting in hepatosteatosis. HFD mice (15–20 per group) were treated with AICAR and without AICAR. HFD mice were treated with DEN, with and without AICAR. Mouse liver tissues were examined histologically using lipid histochemical stains, immunohistochemistry, and immunofluorescence. Levels of cytokines, alanine transaminase (ALT), triacylglyceride (TAG), and apoptosis were determined. Western blot was used to detect AMPK, pAMPK, STAT3, and pSTAT3. Real-time polymerase chain reaction (RT-PCR) detected expression of the ACL, FAS, CD36, ATGL, CPT1, and IL6 genes.

Results

In the HFD mouse model, AICAR treatment inhibited hepatic lipid synthesis and IL-6 expression. In the DEN-treated mice, AICAR treatment reduced tumorigenesis, IL-6 signaling, and STAT3 activation. Short-term AICAR treatment had no significant effect in advanced HCC.

Conclusions

In an HFD mouse model, treatment with AICAR reduced the development of hepatosteatosis, and following treatment with the liver carcinogen, DEN, AICAR reduced the development of HCC. These preliminary findings support further studies on the role of AICAR in fatty liver disease and HCC.

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

Background

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

Objective

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

Materials and methods

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

Results

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

Conclusion

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

Leitzmann M, Brenner*2 H, Mons*2 U. Cancers Due to Excess Weight, Low Physical Activity, and Unhealthy Diet

BACKGROUND

Excess weight, low physical activity, low intakes of dietary fiber, fruits, and vegetables, and high meat and salt intake increase cancer risk.

METHODS

Numbers and proportions (population-attributable fractions, PAF) of incident cancer cases in Germany in 2018 attributable to these factors were estimated by sex and age groups for ages 35 to 84 years using population projections, national cancer incidence and exposure data, and published risk estimates.

RESULTS

Estimated numbers (percentages) of attributable cancers were 30 567 (7%) for excess weight, 27 081 (6%) for low physical activity, 14 474 (3%) for low dietary fiber intake, 9447 (2%) for low fruit and vegetable consumption, 9454 (2%) and 1687 (0.4%) for processed meat and high red meat consumption, respectively, and 1204 (0.3%) for high salt intake. Excess weight substantially contributed to endometrial, renal, and liver cancer (PAF = 24 to 35%). Low physical activity contributed to endometrial, renal, and lung cancer (PAF = 15 to 19%), and dietary factors mainly contributed to colorectal, breast, and lung cancer (PAF = 9 to 16%).

CONCLUSION

A considerable proportion of cancer cases are attributable to excess weight, physical inactivity, and unhealthy dietary habits. Major prevention efforts are needed to reduce the cancer incidence attributable to these avoidable factors.

Epidemiology, prevention, screening, diagnosis, and evaluation: update of the ICUD-SIU joint consultation on bladder cancer

PURPOSE

To update current recommendations on prevention, screening, diagnosis, and evaluation of bladder cancer (BC) based on a thorough assessment of the most recent literature on these topics.

METHODS

A non-systematic review was performed, including articles until June 2017. A variety of original articles, reviews, and editorials were selected according to their epidemiologic, demographic, and clinical relevance. Assessment of the level of evidence and grade of recommendations was performed according to the International Consultation on Urological Diseases grading system.

RESULTS

BC is the ninth most common cancer worldwide with 430,000 new cases in 2012. Currently, approximately 165,000 people die from the disease annually. Absolute incidence and prevalence of BC are expected to rise significantly during the next decades because of population ageing. Tobacco smoking is still the main risk factor, accounting for about 50% of cases. Smoking cessation is, therefore, the most relevant recommendation in terms of prevention, as the risk of developing BC drops almost 40% within 5 years of cessation. BC screening is not recommended for the general population. BC diagnosis remains mainly based on cystoscopy, but development of new endoscopic and imaging technologies may rapidly change the diagnosis algorithm. The same applies for local, regional, and distant staging modalities.

CONCLUSIONS

A thorough understanding of epidemiology, risk factors, early detection strategies, diagnosis, and evaluation is essential for correct, evidence-based management of BC patients. Recent developments in endoscopic techniques and imaging raise the hope for providing better risk-adopted approaches and thereby improving clinical outcomes.

Incidence of bladder cancer in Benghazi, Libya over the past three decades

There are limited data on the disease of bladder cancer in Libya. The objective of this study was to assess the pattern of incidence and clinical presentation of bladder cancer in Benghazi, Libya. This study was a retrospective cohort analysis conducted among consecutive individuals who were diagnosed and/or were treated for bladder cancer from January 1st 1983 to December 31st 2009. A total of 835 cases of bladder tumour were recorded. The world age-standardized incidence rate was 13.1 and 1.9 per 100,000 for males and females, respectively. The mean (standard deviation) age of all patients was 63.7 (14.7). The majority of patients (n = 750, 89.8%) were male, two-thirds of which (n = 594, 79.2%) were smokers while all female patients were non-smokers. Hematuria was the most frequent presenting symptom. Most tumours were well differentiated, and transitional cell carcinoma was the most frequent histological type. The incidence of bladder cancer in Libya is lower than most developed countries, increases by aging, and is more prevalent among males. The incidence of this disease is expected to grow in developing countries such as Libya because of increase in smoking popularity, the shift to sedentary life, diabetes mellitus, and obesity.

Knockdown of fibrous sheath interacting protein 1 expression reduces bladder urothelial carcinoma cell proliferation and induces apoptosis via inhibition of the PI3K/AKT pathway

Background

FSIP1 plays a vital role in tumorigenesis and cancer progression. In bladder cancer, FSIP1 overexpression was associated with poor prognosis of bladder urothelial carcinoma. In this study, we investigated whether FSIP1 is essential in the progression of bladder cancer and the mechanism by which it mediates this effect.

Methods

FSIP1 expression was knocked down in bladder cancer cells using lentiviral-mediated short hairpin RNA (shRNA). FSIP1 expression was detected using Western blotting, immunohistochemistry (IHC), and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The effects of FSIP1 knockdown on tumor cells were assessed using colony formation, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and flow cytometry (FCM) apoptosis assays in vitro and BALB/c nude mouse xenograft model in vivo.

Results

The findings suggested that FSIP1 protein was highly expressed in bladder cancer cell lines. Knockdown of FSIP1 resulted in reduced tumor cell viability, cell cycle arrest at G₀/G₁ phase and apoptosis of bladder cancer cell lines (P<0.05). Moreover, knockdown of FSIP1 expression suppressed the tumor formation and growth of bladder cancer xenografts (P<0.05). At the gene level, knockdown of FSIP1 expression downregulated the activity of the PI3K/AKT signaling pathway.

Conclusion

This study demonstrated that knockdown of FSIP1 suppressed bladder cancer cell malignant behaviors in vitro and in vivo through the inhibition of the PI3K/AKT signaling pathway, suggesting that targeting FSIP1 could be further evaluated as a potential therapeutic strategy in bladder cancer.

Vitamin D, obesity and leptin in relation to bladder cancer incidence and survival: prospective protocol study

INTRODUCTION

Bladder cancer (BC) (including renal pelvis, ureter and urethra) is one of the most common urogenital cancers and the fourth most frequent cancer in men in the USA. In Norway, the incidence of BC has increased over the last decades. The age-standardised incidence rates per 100 000 for 2011-2015 were 53.7 in men and 16.5 in women. Compared to the 5-year period 2006-2010, the percentage increase in incidence was 6.1% in men and 12.3% in women. The recurrence rate of BC is over 50%, the highest recurrence rate of any malignancy. Smoking and occupational exposure to aromatic amines are recognised as the major risk factors. Recently, low-serum level of 25-hydroxy vitamin D (25(OH)D) and obesity have been suggested to increase the BC risk, and leptin, which is important in weight regulation, may be involved in bladder carcinogenesis. More knowledge on potential risk factors for BC is necessary for planning and implementing primary prevention measures.

METHODS AND ANALYSES

Cohort and nested case-control studies will be carried out using the population-based Janus Serum Bank Cohort consisting of prediagnostic sera, clinical measurement data (body height and weight, body surface area and weight change over time, blood pressure, cholesterol and triglycerides) and self-reported information on lifestyle factors (smoking, physical activity). Participants were followed from cohort inclusion (1972-2003) through 2014. The cohort will be linked to the Cancer Registry of Norway (cancer data), the National Cause of Death Registry (date and cause of death), National Population Registry (vital status) and Statistic Norway (education and occupation). Serum samples will be analysed for 25(OH)D, vitamin D binding protein, leptin, albumin, calcium and parathyroid hormone. Cox regression and conditional logistic regression models and mediation analysis will be used to estimate association between the exposures and BC.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Committee for Medical Research Ethics and is funded by the Norwegian Cancer Society. Results will be published in peer-reviewed journals, at scientific conferences and through press releases.

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

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

Estimating the impact of body mass index on bladder cancer risk: Stratification by smoking status

We estimated the impact of obesity on bladder cancer with stratification by smoking status using nationally representative data on the Korean population from the National Health Insurance System (NHIS). Of the 45,850,458 people who underwent at last one health examination from 2009 to 2012, 23,378,895 without bladder cancer were followed from the January 2009 to the December 2015. First, the HR for bladder cancer was lowest in people with a BMI < 18.5 (HR = 0.92) and highest for those with BMI ≥ 30 (HR = 1.17) in multiple Cox regression analyses. The positive association between bladder cancer and BMI showed an increasing trend beyond the reference BMI. Second, an analysis of HR for bladder cancer stratified by obesity across smoking status strata showed a significant trend of increasing HR for bladder cancer across obesity and smoking status in multivariate-adjusted models. Conclusively, this population-based study showed that increasing BMI was a risk factor for bladder cancer independent of confounding variables. When stratified by smoking status, there was still a positive association between bladder cancer and BMI (P for trend < 0.01).

Influence of diabetes on the risk of urothelial cancer according to body mass index: a 10-year nationwide population-based observational study

To examine the association between obesity and urothelial cancer, we used a representative data from the National Health Insurance System (NHIS). Participants included 826,170 men aged 20 years and older who experienced a health examination at least one time between 2004 and 2008. The study thus excluded people aged <20 years and women. We used a multivariate adjusted Cox regression analysis to examine the association between urothelial cancer and body mass index (BMI) via a hazard ratio (HR) and 95% confidence interval (CI).

The age- or multivariable-adjusted HR for urothelial cancer was stratified by BMI. Men with a higher BMI were more likely to acquire urothelial cancer independent of variables. In the population with diabetes, there showed a considerable, increasing trend in the risk of urothelial cancer in the overweight and obesity group, compared to the group with the same BMI but without diabetes. This population-based study showed evidence of an association between obesity and the development of urothelial cancer, where the presence of diabetes increased the risk of urothelial cancer. Additionally, the higher the BMI, the higher the risk for urothelial cancer.

SGLT2 inhibitors and risk of cancer in type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials

AIMS/HYPOTHESIS

The association between sodium-glucose cotransporter 2 (SGLT2) inhibitors and the risk of cancer in individuals with type 2 diabetes remains uncertain. This study aimed to evaluate the risk of cancer associated with SGLT2 inhibitor treatment of type 2 diabetes.

METHODS

We systematically searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov from inception to 15 February 2017 to identify eligible randomised controlled trials (RCTs) that report cancer events in individuals with type 2 diabetes treated with SGLT2 inhibitors for at least 24 weeks. We performed pairwise and network meta-analyses as well as a cumulative meta-analysis to calculate ORs and 95% CIs.

RESULTS

In total, 580 incidences of cancer among 34,569 individuals were identified from 46 independent RCTs with a mean trial duration of 61 weeks. When compared with comparators (placebo or other active glucose-lowering treatments), SGLT2 inhibitors were not significantly associated with an increased risk of overall cancer (OR 1.14 [95% CI 0.96, 1.36]). For pre-specified cancer types, the risk of bladder cancer might be increased with SGLT2 inhibitors (OR 3.87 [95% CI 1.48, 10.08]), especially empagliflozin (OR 4.49 [95% CI 1.21, 16.73]). Interestingly, canagliflozin might be protective against gastrointestinal cancers (OR 0.15 [95% CI 0.04, 0.60]).

CONCLUSIONS/INTERPRETATION

Current evidence from short-term RCTs did not indicate a significantly increased risk of overall cancer among individuals with type 2 diabetes using SGLT2 inhibitors. Given the short-term trial durations and uncertainty of evidence, future long-term prospective studies and post-marketing surveillance studies are warranted.

Gallic acid inhibits bladder cancer cell proliferation and migration via regulating fatty acid synthase (FAS)

Bladder cancer is known as the world’s ninth most prevalent cancer in 2012. New cytotoxic drugs have created considerable progress in the treatment. Gallic acid (GA) has been shown to inhibit carcinogenesis in animal models and various cancer cell lines. The aim of the present study was to evaluate the effect of GA on proliferation and migration inhibition of a bladder cancer cell line. The results showed that GA inhibited fatty acid synthase (FAS) activity and increased ER alpha level of TSGH-8301 bladder cancer cell. GA regulated the cell proliferation via the PI3K/AKT and MAPK/ERK pathway. Immunoprecipitation assay demonstrated that GA decreased Skp2 protein level and attenuated Skp2-p27 association. It was suggested that GA acted upstream of the proteasome to control p27 levels and ultimately inhibited G2/M phase transition. Further, transwell chambers assay showed that GA suppressed bladder cancer cell invasion and migration through p-AKT/MMP-2 signaling pathway. The finding indicated that GA inhibited TSGH-8301 bladder cancer cell growth, invasion and migration through inhibition of fatty acid synthase.

Spatial Analysis of Ambient PM2.5 Exposure and Bladder Cancer Mortality in Taiwan

Fine particulate matter (PM_2.5) is an air pollutant that is receiving intense regulatory attention in Taiwan. In previous studies, the effect of air pollution on bladder cancer has been explored. This study was conducted to elucidate the effect of atmospheric PM_2.5 and other local risk factors on bladder cancer mortality based on available 13-year mortality data. Geographically weighted regression (GWR) was applied to estimate and interpret the spatial variability of the relationships between bladder cancer mortality and ambient PM_2.5 concentrations, and other variables were covariates used to adjust for the effect of PM_2.5. After applying a GWR model, the concentration of ambient PM_2.5 showed a positive correlation with bladder cancer mortality in males in northern Taiwan and females in most of the townships in Taiwan. This is the first time PM_2.5 has been identified as a risk factor for bladder cancer based on the statistical evidence provided by GWR analysis.

New insight for metformin against bladder cancer

International Agency for Research on Cancer (IARC) estimated that bladder cancer is the ninth most common cancer in the world, with 430,000 new cases and 165,000 deaths in 2012. Bladder cancer represents the fourth most common cancer in men and ninth most common cancer in women. It is the second most prevalent cancer in men 60 years of age or older in United States. Looking further down, continuing advancements in cancer research could potentially offer more choices for clinician and patient with longer survival and better quality of life. Although, bladder cancer represents an ideal tumor model to test and apply cancer prevention strategies; there are limited studies about application of metformin in the management of bladder cancer. Here, I will shed light on the proposed mechanisms of anti-carcinogenic effects of metformin and cohort of these mechanisms with the novel application of metformin as therapy of bladder cancer.

Adiposity and cancer at major anatomical sites: umbrella review of the literature

Objective To evaluate the strength and validity of the evidence for the association between adiposity and risk of developing or dying from cancer.Design Umbrella review of systematic reviews and meta-analyses.Data sources PubMed, Embase, Cochrane Database of Systematic Reviews, and manual screening of retrieved references.Eligibility criteria Systematic reviews or meta-analyses of observational studies that evaluated the association between indices of adiposity and risk of developing or dying from cancer.Data synthesis Primary analysis focused on cohort studies exploring associations for continuous measures of adiposity. The evidence was graded into strong, highly suggestive, suggestive, or weak after applying criteria that included the statistical significance of the random effects summary estimate and of the largest study in a meta-analysis, the number of cancer cases, heterogeneity between studies, 95% prediction intervals, small study effects, excess significance bias, and sensitivity analysis with credibility ceilings.Results 204 meta-analyses investigated associations between seven indices of adiposity and developing or dying from 36 primary cancers and their subtypes. Of the 95 meta-analyses that included cohort studies and used a continuous scale to measure adiposity, only 12 (13%) associations for nine cancers were supported by strong evidence. An increase in body mass index was associated with a higher risk of developing oesophageal adenocarcinoma; colon and rectal cancer in men; biliary tract system and pancreatic cancer; endometrial cancer in premenopausal women; kidney cancer; and multiple myeloma. Weight gain and waist to hip circumference ratio were associated with higher risks of postmenopausal breast cancer in women who have never used hormone replacement therapy and endometrial cancer, respectively. The increase in the risk of developing cancer for every 5 kg/m2 increase in body mass index ranged from 9% (relative risk 1.09, 95% confidence interval 1.06 to 1.13) for rectal cancer among men to 56% (1.56, 1.34 to 1.81) for biliary tract system cancer. The risk of postmenopausal breast cancer among women who have never used HRT increased by 11% for each 5 kg of weight gain in adulthood (1.11, 1.09 to 1.13), and the risk of endometrial cancer increased by 21% for each 0.1 increase in waist to hip ratio (1.21, 1.13 to 1.29). Five additional associations were supported by strong evidence when categorical measures of adiposity were included: weight gain with colorectal cancer; body mass index with gallbladder, gastric cardia, and ovarian cancer; and multiple myeloma mortality.Conclusions Although the association of adiposity with cancer risk has been extensively studied, associations for only 11 cancers (oesophageal adenocarcinoma, multiple myeloma, and cancers of the gastric cardia, colon, rectum, biliary tract system, pancreas, breast, endometrium, ovary, and kidney) were supported by strong evidence. Other associations could be genuine, but substantial uncertainty remains. Obesity is becoming one of the biggest problems in public health; evidence on the strength of the associated risks may allow finer selection of those at higher risk of cancer, who could be targeted for personalised prevention strategies.

Promotion of Weight Loss by Health-Care Professionals: Implications for Influencing Weight Loss/Control Behaviors

PURPOSE

Despite evidence demonstrating that health-care providers (HCPs) can effectively promote health behaviors and weight loss among their patients, the extent to which HCPs promote weight loss among overweight and obese adults is not fully understood as the studies on this topic have mostly been conducted in convenience samples. Therefore, the purpose of this study was to examine the extent to which HCPs promote weight loss among overweight and obese adults.

DESIGN

Cross-sectional.

SETTING

National Health and Nutrition Examination Survey 2011-2012.

PARTICIPANTS

A total of 2291 overweight or obese adults (males 46%, females 54%) of varying racial/ethnic backgrounds.

MEASURES

Weight loss/maintenance promotion from HCP was assessed via patient self-report, with weight status assessed via measured body mass index.

ANALYSIS

Descriptive statistics and regression.

RESULTS

Among those receiving health care in the past 12 months, 19.4% of overweight, 46.8% of obese class 1, 62.8% of obese class 2, and 76.9% of obese class 3 adults were advised to lose/control their weight, and the odds of being advised to control/lose weight by HCP increased accordingly. These results were similar when evaluated across various subpopulations (eg, age, gender). Those who received advice to lose/control weight had 3 times the odds of adopting weight loss/control behaviors (odds ratio = 3.1).

CONCLUSIONS

Additional weight loss promotion among overweight and all classes of obese adults is needed from HCP.

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.

Obesity and Outcomes in Patients with Metastatic Urothelial Carcinoma

Background: Obesity has been associated with worse outcomes in patients with clinically localized urothelial cancer. However, this impact has not been evaluated in metastatic disease.

Objective: To assess the impact of obesity on outcomes of patients with metastatic urothelial cancer.

Methods: Data from 537 patients were aggregated from eight phase II and phase III clinical trials investigating first-line cisplatin-based combination therapy in metastatic urothelial cancer. Chemotherapy regimen, adverse events, treatment response, and survival outcomes were compared across body mass index (BMI) and body surface area (BSA) categories.

Results: BMI was classified according to WHO criteria (<18.5 underweight, 18.5–24.99 normal weight, 25–29.99 overweight, >30 obese). BSA was classified as either below or greater than or equal to (average for this cohort (1.87 m² for males and 1.66 m² for females). There was no significant difference in number of chemotherapy cycles, adverse events, and response rate or survival outcomes (overall and progression-free) across BMI and BSA categories. There was no significant difference in adverse events across BMI categories, but the incidences of embolic events and renal failure were higher in patients with an average or higher BSA than those with a lower than average BSA (6.6% vs. 3.1% for renal failure p = 0.06; 5.9% vs. 2.7% for renal failure, p = 0.07). There was no significant difference in response rate or survival outcomes (overall and progression-free) amongst BMI and BSA categories.

Conclusions: Obese patients with metastatic urothelial cancer on cisplatin-based therapies have similar response rates, survival outcomes, and tolerability of cisplatin-based therapy to non-obese patients.

Obesity, Physical Activity and Bladder Cancer

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

Goodness of fit tools for dose-response meta-analysis of binary outcomes

Goodness of fit evaluation should be a natural step in assessing and reporting dose-response meta-analyses from aggregated data of binary outcomes. However, little attention has been given to this topic in the epidemiological literature, and goodness of fit is rarely, if ever, assessed in practice. We briefly review the two-stage and one-stage methods used to carry out dose-response meta-analyses. We then illustrate and discuss three tools specifically aimed at testing, quantifying, and graphically evaluating the goodness of fit of dose-response meta-analyses. These tools are the deviance, the coefficient of determination, and the decorrelated residuals-versus-exposure plot. Data from two published meta-analyses are used to show how these three tools can improve the practice of quantitative synthesis of aggregated dose-response data. In fact, evaluating the degree of agreement between model predictions and empirical data can help the identification of dose-response patterns, the investigation of sources of heterogeneity, and the assessment of whether the pooled dose-response relation adequately summarizes the published results. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.