Non-Occupational Risk Factors for Bladder Cancer a Case-Control Study

Meat Intake and the Risk of Bladder Cancer: A Systematic Review and Meta-Analysis of Observational Studies

The evidence for the association between meat intake and the risk of bladder cancer (BC) is still inconclusive. A total of 29 studies involving 1,475,125 participants and 18,836 cases of BC were included in the meta-analysis. Among these studies, 11 reported total meat intake, 20 reported red meat intake, 19 reported processed meat intake, 15 reported white meat intake, and 15 reported fish intake. The results suggested that there was an overall increase in BC risk associated with total meat intake (RR = 1.10; 95% confidence interval: 0.92-1.31; I² = 55.20%; P = 0.014), and a higher red meat (RR = 1.23; 95% CI: 1.08-1.39; I² = 51.30%; P = 0.004) or processed meat (RR = 1.16; 95% CI: 1.08-1.25; I² = 28.00%; P = 0.125) intake may increase the risk of BC. In contrast, a higher intake of fish (RR = 0.80; 95% CI: 0.67-0.95; I² = 62.90%; P = 0.001) was inversely associated with the risk of BC. Moreover, we did not observe an association between white meat (RR = 0.96; 95% CI: 0.83-1.10; I² = 53.70%; P = 0.007) and the risk of BC. Our findings suggested that dietary intervention may be an effective approach to preventing BC, which still needs to be confirmed by further well-designed observational studies.

Understanding cancer etiology: A review of the evidence-based Ayurvedic framework of cancer etiologies

Background of the Study

As many as 10 million people have died from cancer globally in 2020, making it the top cause of mortality in the globe. Cancer develops as a result of the multi-stage process by which normal cells convert into tumor cells, progressing from a precancerous lesion to a malignant tumor. By avoiding risk factors and applying existing evidence-based preventative techniques, 30%-50% of malignancies may be averted. In order to avoid cancer, it is essential to know the specific causes of the disease. Nidanas, or etiologies, are well-described in Ayurvedic science. Here, the causes of cancer have been outlined so that the knowledge may be used effectively to avoid the disease.

Aims

Identification of cancer etiologies that have been described in classics. Evidence-based understanding of these etiologies and to comprehend the significance of etiologies in cancer prevention.

Materials and methods

A thorough evaluation of literature, including ancient Ayurvedic classics, modern medical texts, and articles published in reputable journals, was conducted to meet the study's goals and objectives.

Results

According to Ayurveda, there are three distinct phases of tumorigenesis: chronic inflammation, precancerous development, Granthi (a benign glandular swelli ng), and Arbuda (a precancerous tumor) (definite malignancy). A growing body of evidence suggests that the tumor microenvironment, which is predominantly controlled by inflammatory cells, is an essential player in the neoplastic process.

Conclusion

Although inflammation is coming into the picture just now in the contemporary world, Ayurveda has described this as a leading cause 5000 years back. It is evident that diet and lifestyle play a crucial role in the etiology of Shoth (inflammation).

Health Promoting Properties of Cereal Vinegars

Vinegar has been used for its health promoting properties since antiquity. Nowadays, these properties are investigated, scientifically documented, and highlighted. The health benefits of vinegar have been associated with the presence of a variety of bioactive components such as acetic acid and other organic acids, phenolic compounds, amino acids, carotenoids, phytosterols, vitamins, minerals, and alkaloids, etc. These components are known to induce responses in the human body, such as antioxidant, antidiabetic, antimicrobial, antitumor, antiobesity, antihypertensive, and anti-inflammatory effects. The diversity and levels of bioactive components in vinegars depend on the raw material and the production method used. Cereal vinegars, which are more common in the Asia-Pacific region, are usually made from rice, although other cereals, such as millet, sorghum, barley, malt, wheat, corn, rye, oats, bran and chaff, are also used. A variety of bioactive components, such as organic acids, polyphenols, amino acids, vitamins, minerals, alkaloids, melanoidins, butenolides, and specific compounds such as γ-oryzanol, tetramethylpyrazine, γ-aminobutyric acid, etc., have been associated with the health properties of cereal vinegars. In this work, the bioactive components and the related health effects of cereal vinegars are reviewed, and the most recent scientific literature is presented and discussed.

Red and processed meat consumption and risk of bladder cancer: a dose-response meta-analysis of epidemiological studies

Background/objectives

Several epidemiological studies have analyzed the associations between red and processed meat and bladder cancer risk but the shape and strength of the associations are still unclear. Therefore, we conducted a dose–response meta-analysis to quantify the potential association between red and processed meat and bladder cancer risk.

Methods

Relevant studies were identified by searching the PubMed database through January 2016 and reviewing the reference lists of the retrieved articles. Results were combined using random-effects models.

Results

Five cohort studies with 3262 cases and 1,038,787 participants and 8 cases–control studies with 7009 cases and 27,240 participants met the inclusion criteria. Red meat was linearly associated with bladder cancer risk in case–control studies, with a pooled RR of 1.51 (95% confidence interval (CI) 1.13, 2.02) for every 100 g increase per day, while no association was observed among cohort studies (P heterogeneity across study design = 0.02). Based on both case–control and cohort studies, the pooled relative risk (RR) for every 50 g increase of processed meat per day was 1.20 (95% CI 1.06, 1.37) (P heterogeneity across study design = 0.22).

Conclusions

This meta-analysis suggests that processed meat may be positively associated with bladder cancer risk. A positive association between red meat and risk of bladder cancer was observed only in case–control studies, while no association was observe in prospective studies.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-016-1356-0) contains supplementary material, which is available to authorized users.

Epidemiologic and socioeconomic status of bladder cancer in Mazandaran Province, northern Iran

BACKGROUND

Bladder cancer is one the most common malignancies of the genitourinary tract. The present study aimed to assess the epidemiology, of bladder cancer in Mazandaran, a large province in northern Iran as high-incidence cancer area, during a 2-year period.

METHODS

The data for this study were obtained from the population-based cancer registry of the Vice-Chancellory for Health Affairs of Mazandaran University of Medical Sciences and Mazandaran hospitals between March 1, 2010 and March 1, 2011. Demographic data, including sex, age, residency and symptoms were investigated through careful review of medical records. Using a questionnaire protocol, several variables were assessed for these cases such as smoking, history of opium, vegetable consumption habits, and history of other cancers.

RESULTS

A total of 112 cases were analyzed, 98 (87.5%) in men and 14 (12.5%) in women (mean age of 68.0 ± 14.6 years). Urban and rural residence were 60.7% and 39.3%. Tobacco and opium use were found in 45.5% and 21.4% of patients, respectively. Approximately 60% consumed vegetables an average of fewer than one time per day. Hematuria was the first symptom in these cases which were mainly diagnosed as having bladder cancer by ultrasonography.

CONCLUSION

The results showed that bladder cancer tends to be found in the elderly and the male to female ratio is high. Macroscopic hematuria is a very important symptom for indicating probably urothelial tumor that should be followed up patients with transabdominal ultrasonography as a routine modality.

Meat and components of meat and the risk of bladder cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Meat could be involved in bladder carcinogenesis via multiple potentially carcinogenic meat-related compounds related to cooking and processing, including nitrate, nitrite, heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs). The authors comprehensively investigated the association between meat and meat components and bladder cancer.

METHODS

During 7 years of follow-up, 854 transitional cell bladder-cancer cases were identified among 300,933 men and women who had completed a validated food-frequency questionnaire in the large prospective NIH-AARP Diet and Health Study. The authors estimated intake of nitrate and nitrite from processed meat and HCAs and PAHs from cooked meat by using quantitative databases of measured values. Total dietary nitrate and nitrite were calculated based on literature values.

RESULTS

The hazard ratios (HR) and 95% confidence intervals (CI) for red meat (HR for fifth quintile compared with first quintile, 1.22; 95% CI, 0.96-1.54; P(trend) = .07) and the HCA 2-amino-1 methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) (HR, 1.19; 95% CI, 0.95-1.48; P(trend) = .06) conferred a borderline statistically significant increased risk of bladder cancer. Positive associations were observed in the top quintile for total dietary nitrite (HR, 1.28; 95% CI, 1.02-1.61; P(trend) = .06) and nitrate plus nitrite intake from processed meat (HR, 1.29; 95% CI, 1.00-1.67; P(trend) = .11).

CONCLUSIONS

These findings provided modest support for an increased risk of bladder cancer with total dietary nitrite and nitrate plus nitrite from processed meat. Results also suggested a positive association between red meat and PhIP and bladder carcinogenesis.

DNA methylation profiles delineate etiologic heterogeneity and clinically important subgroups of bladder cancer

DNA methylation profiles can be used to define molecular cancer subtypes that may better inform disease etiology and clinical decision-making. This investigation aimed to create DNA methylation profiles of bladder cancer based on CpG methylation from almost 800 cancer-related genes and to then examine the relationship of those profiles with exposures related to risk and clinical characteristics. DNA, derived from formalin-fixed paraffin-embedded tumor samples obtained from incident cases involved in a population-based case-control study of bladder cancer in New Hampshire, was used for methylation profiling on the Illumina GoldenGate Methylation Bead Array. Unsupervised clustering of those loci with the greatest change in methylation between tumor and non-diseased tissue was performed to defined molecular subgroups of disease, and univariate tests of association followed by multinomial logistic regression was used to examine the association between these classes, bladder cancer risk factors and clinical phenotypes. Membership in the two most methylated classes was significantly associated with invasive disease (P < 0.001 for both class 3 and 4). Male gender (P = 0.04) and age >70 years (P = 0.05) was associated with membership in one of the most methylated classes. Finally, average water arsenic levels in the highest percentile predicted membership in an intermediately methylated class of tumors (P = 0.02 for both classes). Exposures and demographic associated with increased risk of bladder cancer specifically associate with particular subgroups of tumors defined by DNA methylation profiling and these subgroups may define more aggressive disease.

Risk factors for bladder cancer

AIMS AND BACKGROUND

To summarize risk factors for bladder cancer, emphasizing the role of recently established associations and to present some ongoing debates on the issue.

METHODS

A systematic literature search was performed using MEDLINE database on bladder cancer risk factors between January 1985 and June 2006 and by detailed examination of the references of original articles, reviews and monographs retrieved.

RESULTS

Cigarette smoking is recognized as the main cause of bladder cancer and accounts for about 50% of cases in developed countries. A strong link exists between the amount and duration of cigarette smoking. A high risk of bladder carcinoma has been observed in workers exposed to some aromatic amines. Based on these and other occupational risks, it has been estimated that 5-10% of bladder carcinomas in industrialized countries were due to exposures of occupational origin. Infectious agents have a major influence on bladder cancer risks in the areas of the world where Schistosoma haematobium infestation is endemic. Other potential risk factors for bladder cancer are other urinary tract infections and drinking tap water with chlorination by-products or arsenic. Exposure to certain drugs, like cyclophosphamide used in chemotherapy and heavy consumption of phenacetin-containing analgesics, has been shown to cause bladder cancer in humans. Total fluid intake and high consumption of fruits and vegetables are probably associated with a small decrease in risk.

CONCLUSIONS

Avoidance of tobacco smoking and incriminated occupational exposures, habitual intake of fresh fruits and vegetables, and prevention and control of urinary tract infections should be recommended for bladder cancer prevention. Further studies are required to assess the role of genetic polymorphisms and their modifying effect of lifestyle risk factors for bladder cancer occurrence and to evaluate the benefit of bladder cancer screening, particularly in those at high risk.

Promoter hypermethylation is associated with current smoking, age, gender and survival in bladder cancer

Hypermethylation of tumor suppressor genes is central to the pathogenesis of human malignancy, yet this alteration's etiology remains unclear, and its clinical impact has not yet been studied using an approach that can yield directly generalizable results. Therefore, we sought to examine both of these issues in bladder cancer, seeking to understand the characteristics of epidemiologically well-defined patient tumors with differing levels of methylation silencing. We analyzed epigenetic silencing of 16 genes in a population-based incident case series of 331 bladder transitional cell carcinomas. We utilized a novel item response theory (IRT) model, to examine, in an unbiased fashion, the relationship of patient characteristics, carcinogen exposure history and tumor characteristics with the underlying propensity for gene hypermethylation. Age, male gender and current cigarette smoking were significantly positively associated with the methylation latent trait. Promoter hypermethylation as a latent trait significantly predicted both non-invasive/high-grade and invasive stage disease and was also significantly associated with survival, with each unit increase in the latent trait resulting in a 30% increase in the risk of death. This work, studying all stages and grades of incident bladder cancer, provides definitive evidence that carcinogen exposures play a critical role in selecting these alterations in tumorous clones and that epigenetic silencing is a strong and significant predictor of tumor stage and overall patient survival. Finally, our novel approach provides insight into the etiology of promoter hypermethylation, suggesting that selected, carcinogen-exposed individuals have a greater propensity for hypermethylation that is associated with more aggressive, fatal disease.

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

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

Bladder cancer risk in sales workers: artefact or cause for concern?

BACKGROUND

A large number of epidemiological studies have reported positive associations between bladder cancer and sales occupations. We investigated whether these findings are likely to be due to chance, confounding or publication bias, or may involve causal associations.

METHODS

Studies reporting bladder cancer risk-estimates for sales occupations were reviewed. Using meta-analyses we assessed heterogeneity and publication bias, and derived summary estimates.

RESULTS

Eighteen publications were identified, reporting 85 risk-estimates for sales-work. Meta-estimates were elevated for men (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.01-1.21) and women (OR = 1.36, 95% CI = 1.11-1.67). The estimate was heterogeneous for men (p(Q-test) <0.01, women: 0.18) and indicated publication bias for women (p(Egger-test) <0.01, men: 0.40). When including only smoking-adjusted estimates reported irrespective of the strength of the association, the summary estimate for generic groups of sales workers was 0.99 (95% CI 0.90-1.08) for men, and 1.18 (95% CI = 0.99-1.39) for women, without statistically significant heterogeneity or publication bias. For women, risk was positively associated with longer duration of sales-employment in three studies.

CONCLUSIONS

Publication bias explained most of the reported increased bladder cancer risk, but sales-work still appeared to be associated with a small risk in women. Possible causal factors include lower frequency of urination and reduced fluid intake.