Silica and asbestos exposure at work and the risk of bladder cancer in Canadian men: a population-based case-control study

Risk of bladder, kidney and prostate cancer from occupational exposure to welding fumes: a systematic review and meta-analysis

BACKGROUND

Our aimed to conduct a meta-analysis of cohort studies on risk of genitourinary (GU) cancers in workers exposed to welding fumes (WF).

METHODS

We performed a systematic review of studies published on Pubmed, Scopus and Embase following PRISMA criteria. Two researchers selected cohort studies on WF exposure. From 2582 articles, 7 non-overlapping studies were included. Quality of studies was scored according to CASP. We run a random effects meta-analysis to calculate the relative risk (RR) and 95% confidence intervals (CI) of GU cancer, overall and stratified by cancer, country, and quality score.

RESULTS

We included seven studies reporting results on GU cancers, including prostate, bladder and kidney cancer (PC, BC, and KC). The RR was 1.19 (95% CI = 1.07-1.32, 16 risk estimates) for GU cancer; 1.13 (95% CI = 0.90-1.42, 4 risk estimates) for PC; 1.26 (95% CI = 0.98-1.60, 7 risk estimates) for BC and 1.28 (95% CI = 1.12-1.47, 5 risk estimates) for KC. Heterogeneity was present in all meta-analyses (p < 0.001). The increased risk was more pronounced in North American than in European studies (respectively, OR = 1.35, 95% CI = 1.18-1.55; OR = 1.13, 95% CI = 1.01-1.27 p heterogeneity = 0.03). There was no heterogeneity according to quality score (p = 0.4). Data were insufficient to investigate associations by industry or welding type. Publication bias for each cancer was excluded.

CONCLUSION

This meta-analysis suggests increased risk of KC and BC, but not of PC, in workers exposed to WF. Confounding by other occupational and non-occupational risk factors could not be excluded. Data were not adequate to address the risk of specific exposure circumstances.

Prevalence and Level of Occupational Exposure to Asbestos in Canada in 2016

Objective

Asbestos use has decreased over time but occupational exposure still exists today due to the presence of asbestos in older buildings. The objective of this study was to update CAREX Canada’s prevalence of exposure estimate from 2006 to 2016, and to assess the level of occupational exposure by industry, occupation, province/territory, and sex.

Methods

Estimates by occupation, industry, province/territory, and sex were calculated using labor force data from the 2016 Census of Population and proportions of workers exposed by occupation and industry, which were previously developed for the 2006 estimates and updated here to reflect new knowledge and changes in exposures. Statistics Canada concordance tables were used to account for changes between the 2006 and 2016 job and industry coding systems. Expert assessment was used to qualitatively assign levels of exposure (low, moderate, or high) for each occupation and industry, with consideration of workers’ proximity and access to asbestos-containing material, and the condition and content of asbestos.

Results

Approximately 235 000 workers are exposed to asbestos on the job in Canada. The majority of Canadian workers exposed to asbestos are male (89%). Only 5% of all exposed workers are in the high-exposure category, while most workers are in the low (49%) or moderate (46%) exposure categories. The construction sector and associated jobs (e.g. carpenters, trades helpers and laborers, electricians) accounted for the majority of exposed workers.

Conclusions

Occupational exposure to asbestos continues to occur in Canada. Updating the prevalence of exposure estimate and adding exposure levels highlights the shift from high to lower-lever exposures associated with asbestos-containing materials remaining in the built environment.

Lung cancer and occupational exposure: hospital-based case-control study

OBJECTIVE

To analyze the relationship between occupation and lung cancer in patients at a national referral hospital for cancer care in southern Brazil.

METHOD

Hospital-based case-control study conducted between February and October 2019. Occupational histories were coded according to international classifications and translated into occupations associated with lung cancer (List A and B). The odds ratios were adjusted for smoking, with a 95% confidence interval, calculated by conditional logistic regression.

RESULTS

99 cases and 227 controls were included. Among men, the occupation of painters (list A) was associated with lung cancer (OR = 14.3; 95% CI: 1.8-116.5), there were no occupations in list B associated with lung cancer. In women, no increased risks were found.

CONCLUSIONS

It has been shown that exposure to occupational carcinogens among repair and construction painters increases the risk of lung cancer.

Scoping Review of 5 Common Occupational Cancers and Their Related Exposures

Background: Occupational cancers can be avoided by removing dangerous chemicals from the workplace or limiting occupational exposure. Approximately, 10 major risk factors account for 85% of all occupational cancers. This scoping review study aimed to determine the most important chemical carcinogens related to 5 known occupational cancers. Methods: In this scoping review, we followed Arksey and O'Malley's 5-step framework. Four databases (PubMed, Web of Science, Google Scholar, Scopus) were systematically reviewed for relevant published papers from January 2000 to September 2021. Studies were included in this scoping review, which examined the effect of carcinogenic (definite and probable) chemical exposures on 5 known occupational cancers (lung, bladder, laryngeal, leukemia, and liver). We reported the types of occupational carcinogens, the geographical diversity of studies, extraction of relative risks (RRs), hazard ratios (HRs), or odds ratios (ORs), and identified gaps in the existing literature. Results: The highest number of studies was related to lung cancer (LC) (n = 26), bladder cancer (BC) (n = 11), laryngeal cancer (LaC) (n = 8), leukemia (LeC) (n = 3), and primary liver cancer (PLC) (n = 2), respectively. Most studies were performed in France and Canada (n = 8), Germany (n = 4), Finland (n = 3), Netherlands (n = 2), and Finland (n = 2), respectively. Furthermore, the most common occupational chemical carcinogens associated with the 5 known occupational cancers were asbestos, benzene, crystalline silica, polycyclic aromatic hydrocarbons (PAH), and diesel motor exhausts (DME). Conclusion: Although the attributable risk of occupational cancers in developing countries is much higher, a small proportion of studies were performed in these countries.

Câncer de pulmão e exposição ocupacional: estudo caso-controle de base hospitalar

RESUMO Objetivo Analisar a relação entre ocupação e câncer de pulmão em pacientes de um hospital de referência nacional para atendimento oncológico no Sul do Brasil. Método Estudo caso-controle de base hospitalar realizado entre fevereiro e outubro de 2019. Os históricos ocupacionais foram codificados de acordo com classificações internacionais e traduzidos em ocupações associadas ao câncer de pulmão (Lista A e B). As odds ratios foram ajustadas para tabagismo, com intervalo de confiança de 95%, calculadas por regressão logística condicional. Resultados Foram incluídos 99 casos e 227 controles. Entre os homens a ocupação de pintores (lista A) estava associada ao câncer de pulmão (OR= 14,3; IC 95%: 1,8-116,5), não houve ocupações da lista B associadas ao câncer de pulmão. Nas mulheres não foram encontrados riscos aumentados. Conclusões Evidenciou-se que a exposição aos carcinógenos ocupacionais entre pintores de reparo e da construção civil aumentam o risco de câncer de pulmão.

Clinical therapies and nano drug delivery systems for urinary bladder cancer

Bladder cancer is the 10^th most commonly occurring malignancy worldwide with a 75% of 5-year survival rate, while it ranks 13^th among the deaths occurring due to cancer. The majority of bladder cancer cases are diagnosed at an early stage and 70% are of non-invasive grade. However, 70% of these cases develop chemoresistance and progress to the muscle invasive stage. Conventional chemotherapy treatments are unsuccessful in curbing chemoresistance, bladder cancer progression while having an adverse side effect, which is mainly due to off-target drug distribution. Therefore, new drug delivery strategies, new therapeutics and therapies or their combination are being explored to develop better treatments. In this regard, nanotechnology has shown promise in the targeted delivery of therapeutics to bladder cancer cells. This review discusses the recent discovery of new therapeutics (chemotherapeutics, immunotherapeutic, and gene therapies), recent developments in the delivery of therapeutics using nano drug delivery systems, and the combination treatments with FDA-approved therapies, i.e., hyperthermia and photodynamic therapy. We also discussed the potential of other novel drug delivery systems that are minimally explored in bladder cancer. Lastly, we discussed the clinical status of therapeutics and therapies for bladder cancer. Overall, this review can provide a summary of available treatments for bladder cancer, and also provide opportunities for further development of drug delivery systems for better management of bladder cancer.