Occupational exposure to asbestos and ovarian cancer: a meta-analysis

Ovarian cancer deaths attributable to asbestos exposure in Lombardy (Italy) in 2000-2018

OBJECTIVES

We aimed to estimate the fraction of deaths from ovarian cancer attributable to asbestos exposure in Lombardy Region, Italy, using a novel approach that exploits the fact that ovarian cancer asbestos exposure is associated with pleural cancer and other risk factors for breast cancer.

METHODS

This ecological study is based on the Italian National Institute of Statistics mortality data. We formulate a trivariate Bayesian joint disease model to estimate the attributable fraction (AF) and the number of ovarian cancer deaths attributable to asbestos exposure from the geographic distribution of ovarian, pleural and breast cancer mortality at the municipality level from 2000 to 2018. Expected deaths and standardised mortality ratios were calculated using regional rates.

RESULTS

We found shared dependencies between ovarian and pleural cancer, which capture risk factors common to the two diseases (asbestos exposure), and a spatially structured clustering component shared between ovarian and breast cancer, capturing other risk factors. Based on 10 462 ovarian cancer deaths, we estimated that 574 (95% credibility interval 388-819) were attributable to asbestos (AF 5.5%; 95% credibility interval 3.7-7.8). AF reaches 34%-47% in some municipalities with known heavy asbestos pollution.

CONCLUSIONS

The impact of asbestos on ovarian cancer occurrence can be relevant, particularly in areas with high asbestos exposure. Estimating attributable cases was possible only by using advanced Bayesian modelling to consider other risk factors for ovarian cancer. These findings are instrumental in tailoring public health surveillance programmes and implementing compensation and prevention policies.

Asbestos history and use

All six fiber types called asbestos can cause all the diseases related to exposure, including lung cancer. Known to the ancients, the modern history of asbestos hazards started in the 1890s with more and more data accumulating over time. Use increased exponentially in the middle of the 20th century with major use coming in construction and ship building. The recognition of asbestos as causing lung cancer dates to the early 1940s.

Environmental asbestos exposure and lung cancer

Apart from living near an asbestos industry site, mine, or in an asbestos-contaminated house, environmental asbestos exposure is observed in certain regions where the (natural) soil is 'contaminated' with asbestos (fibers). In this essay, we review the association between environmental asbestos exposure and lung cancer in Turkey. Other studies have also suggested that environmental asbestos exposure is able to increase the risk of lung cancer. Lung cancer associated with environmental asbestos exposure seems to be diagnosed at a younger age, and the risk for women is in the same range as that for men. Our data indicate that the relationship between exposure dose and risk is linear and that a safe threshold cannot be established. Therefore, people living in areas with increased chances of environmental asbestos exposure should be mentored to take part in smoking cessation programs and considered candidates for inclusion in lung cancer screening programs. There is an obvious need for additional studies on this topic.

Cancer mortality in chrysotile miners and millers, Russian Federation: main results (Asbest Chrysotile Cohort-Study)

BACKGROUND

We investigated mortality in workers of the world's largest chrysotile mine and enrichment factories located in the town of Asbest, Russian Federation.

METHODS

This historical cohort study included all workers employed for at least 1 year between 1975 and 2010 and follow-up until the end of 2015. Cumulative exposure to dust was estimated based on workers' complete occupational history linked to dust measurements systematically collected from the 1950s. Exposure to chrysotile fibers was estimated using dust-to-fiber conversion factors. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated as mortality rate ratios in Poisson regression models.

RESULTS

A total of 30 445 (32% women) workers accumulated 721 312 person-years at risk and 11 110 (36%) died. Of the workers, 54% had more than 30 years since their first exposure. We found an exposure-response between cumulative dust and lung cancer mortality in men. No clear association with dust exposure but a modest increase in the highest category of fiber exposure was seen for lung cancer in women. Mesothelioma mortality was increased (RR = 7.64, 95% CI = 1.18 to 49.5, to at least 80 fibers per cm3 years and RR = 4.56, 95% CI = 0.94 to 22.1, to at least 150 mg/m3 years [dust]), based on 13 deaths. For colorectal and stomach cancer, there were inconsistent associations. No associations were seen for laryngeal or ovarian cancer.

CONCLUSION

In this large-scale epidemiological study in the world's largest active asbestos mine, we confirmed an increased risk of mesothelioma with high fiber exposure and an increasing mortality for lung cancer in men with increasing dust exposure. Less clear-cut increased lung cancer mortality was seen in the women. Continued mortality follow-up is warranted.

Plants, Microorganisms and Their Metabolites in Supporting Asbestos Detoxification-A Biological Perspective in Asbestos Treatment

Many countries banned asbestos due to its toxicity, but considering its colossal use, especially in the 1960s and 1970s, disposing of waste containing asbestos is the current problem. Today, many asbestos disposal technologies are known, but they usually involve colossal investment and operating expenses, and the end- and by-products of these methods negatively impact the environment. This paper identifies a unique modern direction in detoxifying asbestos minerals, which involves using microorganisms and plants and their metabolites. The work comprehensively focuses on the interactions between asbestos and plants, bacteria and fungi, including lichens and, for the first time, yeast. Biological treatment is a prospect for in situ land reclamation and under industrial conditions, which can be a viable alternative to landfilling and an environmentally friendly substitute or supplement to thermal, mechanical, and chemical methods, often characterized by high cost intensity. Plant and microbial metabolism products are part of the green chemistry trend, a central strategic pillar of global industrial and environmental development.

An umbrella review of the evidence associating occupational carcinogens and cancer risk at 19 anatomical sites

Occupational exposure to carcinogens of increasing cancer risk have been extensively suggested. A robust assessment of these evidence is needed to guide public policy and health care. We aimed to classify the strength of evidence for associations of 13 occupational carcinogens (OCs) and risk of cancers. We searched PubMed and Web of Science up to November 2022 to identify potentially relevant studies. We graded the evidence into convincing, highly suggestive, suggestive, weak, or not significant according to a standardized classification based on: random-effects p value, number of cancer cases, 95% confidence interval of largest study, heterogeneity between studies, 95% prediction interval, small study effect, excess significance bias and sensitivity analyses with credibility ceilings. The quality of meta-analysis was evaluated by AMSTAR 2. Forty-eight articles yielded 79 meta-analyses were included in current umbrella review. Evidence of associations were convincing (class I) or highly suggeastive (class II) for asbestos exposure and increasing risk of lung cancer among smokers (RR = 8.79, 95%CI: 5.81-13.25 for cohort studies and OR = 8.68, 95%CI: 5.68-13.24 for case-control studies), asbestos exposure and increasing risk of mesothelioma (RR = 4.61, 95%CI: 2.57-8.26), and formaldehyde exposure and increasing risk of sinonasal cancer (RR = 1.68, 95%CI: 1.38-2.05). Fifteen associations were supported by suggestive evidence (class III). In summary, the current umbrella review found strong associations between: asbestos exposure and increasing risk of lung cancer among smokers; asbestos exposure and increasing risk of mesothelioma; and formaldehyde exposure and higher risk of sinonasal cancer. Other associations might be genuine, but substantial uncertainty remains.

Geographical Disparities in Lung Cancer in Canada: A Review

PURPOSE OF REVIEW

The eastern provinces of Canada exhibit a heightened prevalence and mortality rate of lung cancer compared to their western counterparts. While established risk factors for lung cancer exist in Canada, there remains ambiguity regarding the underlying provincial and territorial trends. This review aims to identify and analyze potential contributors to healthcare inequality, guiding policymakers towards a strategic and sustainable approach at the provincial level.

RECENT FINDINGS

Existing studies emphasize the significant roles played by socio-economic and environmental factors in influencing lung cancer disparities across Canadian provinces. However, a noticeable research gap persists, particularly in systematically examining the factors that amplify geographical disparities in lung cancer incidence and mortality rates within Canada. This review underscores the disparities in lung cancer prevalence and mortality rates between eastern and western Canadian provinces. While socio-economic and environmental factors have been identified as influential, there is an evident need for further research to comprehensively understand and address the underlying contributors to these geographical discrepancies.

Asbestos Exposure and Ovarian Cancer: A Meta-analysis

Background

The International Agency for Research on Cancer (IARC) Monograph conducted a systematic review of the relationship between asbestos and ovarian cancer. However, there may have been information bias due to the undue weight given to few articles. To address this limitation, the present study performed a meta-analysis integrating studies published both before and after the 2012 IARC Monograph on Asbestos, with the aim of investigating the association between asbestos exposure and ovarian cancer.

Methods

A comprehensive search of major journal databases was conducted to identify studies examining the relationship between asbestos exposure and ovarian cancer, including those featured in the 2012 IARC Monograph on Asbestos. A meta-analysis on asbestos exposure and cancer risk was performed.

Results

The meta-analysis of studies published after the 2012 IARC Monograph on Asbestos found a summary Standardized Mortality Ratio (SMR) of 2.04 (95% CI: 1.03-4.05; p = 0.0123; 5 studies), with a significant degree of heterogeneity among the studies (I2 = 72.99%). The combined analysis of 15 studies before and after the 2012 IARC Monograph showed an overall summary SMR of 1.72 (95% CI: 1.43-2.06; p = 0.0349; 15 studies), with a moderate degree of heterogeneity (I2 = 42.99%).

Conclusion

This meta-analysis provides evidence of a significant association between asbestos exposure and ovarian cancer mortality. While the possibility of misdiagnosis in earlier studies cannot be completely ruled out, recent findings suggest a robust correlation between asbestos exposure and ovarian cancer. This highlights the importance of sustained efforts to minimize asbestos exposure and protect public health.

Cause specific mortality in an Italian pool of asbestos workers cohorts

BACKGROUND

Asbestos is a known human carcinogen and is causally associated with malignant mesothelioma, lung, larynx and ovarian cancers.

METHODS

Cancer risk was studied among a pool of formerly asbestos-exposed workers in Italy. Fifty-two Italian asbestos cohorts (asbestos-cement, rolling-stock, shipbuilding, and other) were pooled and their mortality follow-up was updated to 2018. Standardized mortality ratios (SMRs) were computed for major causes of death considering duration of exposure and time since first exposure (TSFE), using reference rates by region, age and calendar period.

RESULTS

The study included 63,502 subjects (57,156 men and 6346 women): 40% who were alive, 58% who died (cause known for 92%), and 2% lost to follow-up. Mortality was increased for all causes (SMR: men = 1.04, 95% confidence interval [CI] 1.03-1.05; women = 1.15, 95% CI 1.11-1.18), all malignancies (SMR: men = 1.21, 95% CI 1.18-1.23; women = 1.29, 95% CI 1.22-1.37), pleural and peritoneal malignancies (men: SMR = 10.46, 95% CI 9.86-11.09 and 4.29, 95% CI 3.66-5.00; women: SMR = 27.13, 95% CI 23.29-31.42 and 7.51, 95% CI 5.52-9.98), lung (SMR: men = 1.28, 95% CI 1.24-1.32; women = 1.26, 95% CI 1.02-1.53), and ovarian cancer (SMR = 1.42, 95% CI 1.08-1.84). Pleural cancer mortality increased during the first 40 years of TSFE (latency), reaching a plateau thereafter.

CONCLUSIONS

Analyses by time-dependent variables showed that the risk for pleural neoplasms increased with latency and no longer increases at long TSFE, consistent with with asbestos clearance from the lungs. Peritoneal neoplasm risk increased over all observation time.

Occupational asbestos exposure and ovarian cancer: updated systematic review

BACKGROUND

The association between asbestos exposure and ovarian cancer has been questioned given the possible misdiagnosis of peritoneal mesothelioma as ovarian cancer.

AIMS

To update a systematic review on ovarian cancer risk in women occupationally exposed to asbestos, exploring the association with the time since first exposure and the duration of exposure.

METHODS

We searched PubMed from 2008 onwards, screened previous systematic reviews, combined standardized mortality ratios (SMR) using random effect models and quantified heterogeneity using the I2 statistic. To assess tumour misclassification, we compared the distribution of observed excess ovarian cancers (OEOC) to that expected (EEOC) from the distribution of peritoneal cancers in strata of latency and exposure duration.

RESULTS

Eighteen publications (20 populations), including a pooled analysis of 21 cohorts, were included. The pooled SMR was 1.79 (95% confidence interval 1.38-2.31), with moderate heterogeneity between studies (I2 = 42%), based on 144 ovarian cancer deaths/cases. The risk was increased for women with indirect indicators of higher exposure, longer duration and latency, and lower for chrysotile than for crocidolite exposure. The effect of duration and latency could not be completely disentangled, since no multivariate analysis was available for time-related variables. The dissimilarity index between OEOC and EEOC for the time since first exposure was small suggesting a similar pattern of risk.

CONCLUSIONS

While some misclassification between ovarian and peritoneal cancers cannot be excluded, the observed excess risk of ovarian cancer should be added to the overall disease burden of asbestos.

Exposome and unhealthy aging: environmental drivers from air pollution to occupational exposures

The aging population worldwide is facing a significant increase in age-related non-communicable diseases, including cardiovascular and brain pathologies. This comprehensive review paper delves into the impact of the exposome, which encompasses the totality of environmental exposures, on unhealthy aging. It explores how environmental factors contribute to the acceleration of aging processes, increase biological age, and facilitate the development and progression of a wide range of age-associated diseases. The impact of environmental factors on cognitive health and the development of chronic age-related diseases affecting the cardiovascular system and central nervous system is discussed, with a specific focus on Alzheimer's disease, Parkinson's disease, stroke, small vessel disease, and vascular cognitive impairment (VCI). Aging is a major risk factor for these diseases. Their pathogenesis involves cellular and molecular mechanisms of aging such as increased oxidative stress, impaired mitochondrial function, DNA damage, and inflammation and is influenced by environmental factors. Environmental toxicants, including ambient particulate matter, pesticides, heavy metals, and organic solvents, have been identified as significant contributors to cardiovascular and brain aging disorders. These toxicants can inflict both macro- and microvascular damage and many of them can also cross the blood-brain barrier, inducing neurotoxic effects, neuroinflammation, and neuronal dysfunction. In conclusion, environmental factors play a critical role in modulating cardiovascular and brain aging. A deeper understanding of how environmental toxicants exacerbate aging processes and contribute to the pathogenesis of neurodegenerative diseases, VCI, and dementia is crucial for the development of preventive strategies and interventions to promote cardiovascular, cerebrovascular, and brain health. By mitigating exposure to harmful environmental factors and promoting healthy aging, we can strive to reduce the burden of age-related cardiovascular and brain pathologies in the aging population.

Banning asbestos in talcum powder: Time for action in India

Long-term use of asbestos-contaminated talcum power has been reported to be the main causative agent for carcinogenesis in many research studies. In recent developments Johnson & Johnson has lost multimillion-dollar lawsuits for being associated with the development of mesothelioma and ovarian cancer by its talc-based baby powder. In May 2020, the company announced, the end of the sale of its baby powder in the USA and Canada and in August 2022, announced the global discontinuation by 2023. However, in India vast proportions of people are using talc-based baby powder and the products are readily available in the market. The purpose of this communication is to create awareness and draw attention of authorities for effective regulation, including prohibition of sale and retraction of the contaminated talc-based products from the Indian market at the earliest.

Role of neighborhood context in ovarian cancer survival disparities: current research and future directions

Ovarian cancer is the fifth leading cause of cancer-associated mortality among US women with survival disparities seen across race, ethnicity, and socioeconomic status, even after accounting for histology, stage, treatment, and other clinical factors. Neighborhood context can play an important role in ovarian cancer survival, and, to the extent to which minority racial and ethnic groups and populations of lower socioeconomic status are more likely to be segregated into neighborhoods with lower quality social, built, and physical environment, these contextual factors may be a critical component of ovarian cancer survival disparities. Understanding factors associated with ovarian cancer outcome disparities will allow clinicians to identify patients at risk for worse outcomes and point to measures, such as social support programs or transportation aid, that can help to ameliorate such disparities. However, research on the impact of neighborhood contextual factors in ovarian cancer survival and in disparities in ovarian cancer survival is limited. This commentary focuses on the following neighborhood contextual domains: structural and institutional context, social context, physical context represented by environmental exposures, built environment, rurality, and healthcare access. The research conducted to date is presented and clinical implications and recommendations for future interventions and studies to address disparities in ovarian cancer outcomes are proposed.

The incidence of malignancies in asbestosis with chrysotile exposure: a large Chinese prospective cohort study

Background

Asbestos exposure is closely related to the occurrence and development of various malignancies. This prospective cohort study aimed to evaluate the incidence rate and potential risk factors in a cohort of asbestosis patients in China.

Methods

The incidence of malignancies was determined in patients who had been exposed to chrysotile asbestos and diagnosed with asbestosis sequentially at Beijing Chaoyang Hospital from 1 January 2007 to 31 December 2019. Cox regression analyses were used to analyze the correlations between clinical variables and asbestosis combined with malignancies.

Results

A total of 618 patients with asbestosis were identified, of whom 544 were eligible for analysis. Among them, 89 (16.36%) were diagnosed with various malignancies. The standardized incidence ratios (SIRs) of patients with asbestosis combined with malignancies were 16.61, 175, 5.23, and 8.77 for lung cancer, mesothelioma, breast cancer, and endometrial carcinoma, respectively. The risks of all malignancies and lung cancer increased with initial exposure before 17 years old, longer asbestos exposure, and smoking.

Conclusions

The SIRs of patients with asbestosis-related malignancies were significantly increased in lung cancer, mesothelioma, breast cancer, and endometrial carcinoma in a hospital-based Chinese cohort. Smoking and the duration of asbestos exposure increased the risk of lung cancer.

Ovarian and Endometrial Endometrioid Carcinoma Following the Use of a Biologic IL-17 Inhibitor

Evidence suggests that IL-17, a pro-inflammatory cytokine, suppresses tumor carcinogenesis; therefore, the use of IL-17 inhibitors accelerates carcinoma growth. We present a case of a perimenopausal female who was diagnosed with synchronous primary ovarian and endometrial endometrioid carcinoma following the use of secukinumab, a monoclonal antibody against IL-17. After eight months of secukinumab, she developed progressive vaginal bleeding, left upper quadrant pain, and abdominal distention. CT imaging displayed a large abdominal mass, and biopsies produced the diagnosis. It is proposed that by inhibiting IL-17, carcinogenesis was expedited. This case highlights a relationship between secukinumab and accelerated carcinogenesis. Consequently, due to the incidence of endometrial carcinoma and the morbidity rate of ovarian carcinoma, individuals taking IL-17 inhibitors may need prophylactic screening and close monitoring.

Attributable Fraction of Cancer Related to Occupational Exposure in Italy

BACKGROUND

Exposure to occupational carcinogens is an important and avoidable cause of cancer. We aimed to provide an evidence-based estimate of the burden of occupation-related cancers in Italy.

METHODS

The attributable fraction (AF) was calculated based on the counterfactual scenario of no occupational exposure to carcinogens. We included exposures classified as IARC group 1 and with reliable evidence of exposure in Italy. Relative risk estimates for selected cancers and prevalences of exposure were derived from large-scale studies. Except for mesothelioma, a 15-20-year latency period between exposure and cancer was considered. The data on cancer incidence in 2020 and mortality in 2017 in Italy were obtained from the Italian Association of Cancer Registries.

RESULTS

The most prevalent exposures were UV radiation (5.8%), diesel exhaust (4.3%), wood dust (2.3%) and silica dust (2.1%). Mesothelioma had the largest AF to occupational carcinogens (86.6%), followed by sinonasal cancer (11.8%) and lung cancer (3.8%). We estimated that 0.9% of cancer cases (N~3500) and 1.6% of cancer deaths (N~2800) were attributable to occupational carcinogens in Italy. Of these, about 60% were attributable to asbestos, 17.5% to diesel exhaust, followed by chromium and silica dust (7% and 5%).

CONCLUSIONS

Our estimates provide up-to-date quantification of the low, but persistent, burden of occupational cancers in Italy.

Occupational asbestos exposure and urinary bladder cancer: a systematic review and meta-analysis

PURPOSE

There is conflicting evidence on the association between asbestos exposure and bladder cancer. We performed a systematic review and meta-analysis to provide evidence on occupational asbestos exposure and the risk of mortality and incidence of bladder cancer.

METHODS

We searched three relevant electronic databases (Pubmed, Scopus, and Embase) from inception to October 2021. The methodological quality of included articles was evaluated using the US National Institutes of Health tool. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) for bladder cancer, as well as respective 95% confidence intervals (CIs), were extracted or calculated for each included cohort. Main and subgroup meta-analyses according to first year of employment, industry, sex, asbestos type, and geographic region were performed.

RESULTS

Fifty-nine publications comprising 60 cohorts were included. Bladder cancer incidence and mortality were not significantly associated with occupational asbestos exposure (pooled SIR: 1.04, 95% CI: 0.95-1.13, P = 0.000; pooled SMR: 1.06, 95% CI: 0.96-1.17, P = 0.031). Bladder cancer incidence was higher among workers employed between 1908 and 1940 (SIR: 1.15, 95% CI: 1.01-1.31). Mortality was elevated in asbestos workers cohorts (SMR: 1.12, 95% CI: 1.06-1.30) and in the subgroup analysis for women (SMR: 1.83, 95% CI: 1.22-2.75). No association was found between asbestos types and bladder cancer incidence or mortality. We observed no difference in the subgroup analysis for countries and no direct publication bias evidence.

CONCLUSION

There is evidence that workers with occupational asbestos exposure have a bladder cancer incidence and mortality similar to the general population.

Epidemiology beyond its limits

In 1995, journalist Gary Taubes published an article in Science titled "Epidemiology faces its limits," which questioned the utility of nonrandomized epidemiologic research and has since been cited more than 1000 times. He highlighted numerous examples of research topics he viewed as having questionable merit. Studies have since accumulated for these associations. We systematically evaluated current evidence of 53 example associations discussed in the article. Approximately one-quarter of those presented as doubtful are now widely viewed as causal based on current evaluations of the public health consensus. They include associations between alcohol consumption and breast cancer, residential radon exposure and lung cancer, and the use of tanning devices and melanoma. This history should inform current debates about the reproducibility of epidemiologic research results.

Risk Factors for Ovarian Cancer: An Umbrella Review of the Literature

Several non-genetic factors have been associated with ovarian cancer incidence or mortality. To evaluate the strength and validity of the evidence we conducted an umbrella review of the literature that included systematic reviews/meta-analyses that evaluated the link between non-genetic risk factors and ovarian cancer incidence and mortality. We searched PubMed, EMBASE, Cochrane Database of Systematic Reviews and performed a manual screening of references. Evidence was graded into strong, highly suggestive, suggestive or weak based on statistical significance of the random effects summary estimate and the largest study in a meta-analysis, the number of cases, between-study heterogeneity, 95% prediction intervals, small study effects, and presence of excess significance bias. We identified 212 meta-analyses, investigating 55 non-genetic risk factors for ovarian cancer. Risk factors were grouped in eight broad categories: anthropometric indices, dietary intake, physical activity, pre-existing medical conditions, past drug history, biochemical markers, past gynaecological history and smoking. Of the 174 meta-analyses of cohort studies assessing 44 factors, six associations were graded with strong evidence. Greater height (RR per 10 cm 1.16, 95% confidence interval (CI) 1.11-1.20), body mass index (BMI) (RR ≥ 30 kg/m² versus normal 1.27, 95% CI 1.17-1.38) and three exposures of varying preparations and usage related to hormone replacement therapy (HRT) use increased the risk of developing ovarian cancer. Use of oral contraceptive pill reduced the risk (RR 0.74, 95% CI 0.69-0.80). Refining the significance of genuine risk factors for the development of ovarian cancer may potentially increase awareness in women at risk, aid prevention and early detection.

Frequency of Asbestos Exposure and Histological Subtype of Ovarian Carcinoma

The International Agency for Research on Cancer established a causal link between asbestos exposure and ovarian cancer. However, the exposure frequency and histological characteristics of asbestos-associated ovarian cancers remain to be investigated in detail. This multicenter case-case study assessed the asbestos exposure in ovarian carcinoma (OC) patients, alongside its association with histological subtype. Women were recruited in four hospitals in Lyon, France. Histological reports were reviewed by a pathologist. Patient and family members' data were collected by phone-based questionnaires. Asbestos exposure was defined as direct (occupational and environmental) and indirect (via parents, partners, and children). An industrial hygienist assessed the probability and level of exposure. The 254 enrolled patients (mean age 60 years) reported having an average of 2.3 different jobs (mean working duration 29 years). The prevalence of direct and indirect asbestos exposure was 13% (mean exposure duration 11 years) and 46%, respectively. High-grade serous carcinoma accounted for 73% of all OCs and 82% of histological subtypes in women with direct exposure. After adjustment on a familial history of OC, no significant associations between asbestos exposure (direct and/or indirect) and high-grade serous carcinoma were found. Women with OC had a high prevalence of asbestos exposure. Establishing risk profiles, as reported here, is important in facilitating compensation for asbestos-related OCs and for the surveillance of women at risk.

The association between occupational asbestos exposure with the risk of incidence and mortality from prostate cancer: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence on the association between asbestos exposure and prostate cancer (PCa). Two recent meta-analyses have claimed that exposure is associated with increased PCa incidence and mortality, but they suffer from some methodological flaws. Given the potential importance of this research question, we aimed to perform a methodologically sound systematic review and meta-analysis to investigate the association between occupational asbestos exposure and the incidence of and mortality from PCa.

METHODS

We followed PRISMA guidelines to systematically search for pertinent articles in three relevant electronic databases: Pubmed, Scopus, and Embase, from their inception to July 2020. The methodological quality of included articles was evaluated using the US National Institutes of Health tool. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) for PCa, as well as respective 95% confidence intervals (CIs), were extracted or calculated for each included cohort. Main and subgroup meta-analyses according to first year of employment, industry, asbestos type, and geographic region were performed.

RESULTS

Sixty-five articles comprising 68 cohorts were included. PCa incidence and mortality were not significantly associated with occupational asbestos exposure (pooled SIR: 1.06, 95% CI: 1.00-1.13, P = 0.062; pooled SMR: 1.03, 95% CI: 0.99-1.06, P = 0.115). PCa incidence was higher among workers employed after 1960 (SIR: 1.10, 95% CI: 1.01-1.20). Pooled SIR was elevated in European (SIR: 1.09, 95% CI: 1.01-1.18) and UK cohorts (SIR: 1.05, 95% CI: 1.02-1.09). Mortality was elevated in North American cohorts (SMR: 1.06, 95% CI: 1.02-1.10). Studies of lower methodological quality appeared to yield elevated SIRs or SMRs.

CONCLUSIONS

This systematic review and meta-analysis provides evidence that men with occupational asbestos exposure have a PCa incidence and mortality similar to that of the general population. Temporal and geographical variables seem to be related to higher SMR or SIR.

Malignant mesothelioma: Ongoing controversies about its etiology in females

Malignant mesothelioma (MM) is one of the most aggressive cancers with the poorest of outcomes. There is no doubt that mesothelioma in males is related to asbestos exposure, but some authors suggest that most of the cases diagnosed in females are "idiopathic." In our assessment of the science, the "low risk" of mesothelioma in females is because of the nonsystematic recording of exposure histories among females. Indeed, asbestos exposure is mentioned in only some of the studies that include females. We estimate the risk of MM among females to be close to that in males. The absence of detailed exposure histories should be rectified in future studies involving ​women. As a matter of social justice, the ongoing failure to recognize asbestos as the cause of a majority of cases of MM in females does them, and their kin, a profound disservice.

Asbestos Exposure and Ovarian Cancer - a Gynaecological Occupational Disease. Background, Mandatory Notification, Practical Approach

In 2017, ovarian cancer due to asbestos exposure was designated a new, and thereby the first, gynaecological occupational disease in Germany. Asbestos is a naturally occurring mineral fibre with an annual usage in Germany of 160 000 – 180 000 metric tonnes in the 1960s and 1970s. The carcinogenicity of asbestos for the target organs lungs, larynx, pleura including pericardium, and peritoneum including tunica vaginalis testis has been clearly established for many years. Recent meta-analyses of data from cohort studies have demonstrated that the risk of ovarian cancer roughly doubles in women with occupational exposure to asbestos. Since the group of people with double the risk of developing lung cancer due to work-related asbestos exposure has a 2.25-fold increased risk of mortality from ovarian cancer on average, work-related ovarian cancer has been assigned the same recognition requirements as in occupational lung (and laryngeal) cancer. Thus, gynaecologists must obtain a thorough history of occupational exposure to asbestos, even if it may have taken place long in the past. The law mandates that suspected such cases must be reported to the Statutory Accident Insurance carrier or the State Occupational Safety and Health Agency.

Environmental exposure to asbestos and the risk of lung cancer: a systematic review and meta-analysis

Asbestos is a carcinogen associated with lung cancer, but few studies have examined the increased risk of lung cancer due to environmental asbestos exposure. We performed a systematic review and meta-analysis to evaluate the association between environmental asbestos exposure and lung cancer. We searched for articles on non-occupational or environmental asbestos exposure and lung cancer in PubMed, EMBASE, CINAHL and Web of Science databases. Our review included 15 studies, and except studies on ingestion exposure we performed a meta-analysis for 13 studies with respect to the type of exposure (neighbourhood and domestic/household exposure). Subgroup analyses and meta-regression were also performed. A significant increase in the risk of lung cancer was found for neighbourhood exposure (1.48, 95% CI 1.18 to 1.86), while the risk was not significantly increased for domestic/household exposure (1.04, 95% CI 0.85 to 1.27). With regard to neighbourhood exposure, naturally occurring asbestos and women were both associated with a higher risk of lung cancer; however, such an increase was not significantly greater compared with that associated with other sources of asbestos exposure and men. Although cautious interpretation is needed due to the large degree of heterogeneity and the small number of included studies, our findings imply that living near the source of asbestos increases the risk of lung cancer.

Primary Ovarian Mesothelioma: A Case Series with Electron Microscopy Examination and Review of the Literature

Primary ovarian mesothelioma is a rare, aggressive neoplastic disease with a poor prognosis. At onset, the tumor is only rarely limited to the ovaries and usually already widespread in the peritoneum. The rarity of this entity and the difficulties differentiating it from either ovarian carcinoma or peritoneal mesothelioma may lead to frequent misdiagnoses and may raise some concerns about its histogenesis. Thus, reporting such rare cases is fundamental to gain greater awareness of this neoplasm and try to answer unsolved questions. Herein, we described four cases of histological diagnoses of ovarian mesothelioma extrapolated by the regional mesothelioma register of Apulia (southern Italy). In all cases, a detailed medical history was collected according to national mesothelioma register guidelines. A broad panel of antibodies was used for immunohistochemistry to confirm the diagnoses. Moreover, ovarian tissue samples were also examined by transmission and scanning electron microscopy, detecting asbestos fibers and talc crystals in two cases. Because of the few cases described, we reviewed the English literature in the Medline database, focusing on articles about ovarian mesothelioma "misclassification", "misdiagnosis", "diagnostic challenge" or "diagnostic pitfall" and on unsolved questions about its histogenesis and possible risk factors.

Predicting Long-Term Asbestos Prevalence in Human Lungs, Lymph Nodes, and Remote Organs from Short-Term Murine Experiments

Inhalation of asbestos fibers leads to a suite of fatal diseases that can manifest years, if not decades, after cessation of exposure. The first phase of disease progression occurs as fibers are transported from point of entry in the lungs throughout the entire body. A mathematical model is developed for the disposition of non-chrysotile asbestos in the body and, except for exposure levels, is parameterized by published data on short-term rat experiments. Asbestos exposure in individual humans is determined by matching published long-term lung data for nine patients. The resulting model predicts transport of fibers within the lymphatic system and prevalence of fibers in lymph nodes for these patients with reasonable accuracy. Model predictions for remote organs are compared against published observations. The model consists of a system of globally stable differential equations, and a sensitivity analysis was conducted. The model indicates that fiber density in lymph nodes is correlated with total exposure, level times duration, no matter whether there is a long-term, low-level exposure or short-term, high-level exposure. The model predicts that levels of sequestered asbestos reach steady state within five years of cessation of exposure, a timeline previously not known. The model suggests that the time to steady state is short compared to onset of disease, and that delayed onset of related disease may be a function of chemical and biological processes not in this model.

Serous Ovarian Cancer Caused by Exposure to Asbestos and Fibrous Talc in Cosmetic Talc Powders-A Case Series

OBJECTIVE

Asbestos is a known cause of ovarian cancer. We report 10 cases of serous ovarian cancer among users of Johnson & Johnson (J&J) asbestos-containing "cosmetic" talc products.

METHODS

We conducted an asbestos exposure assessment during talc application and analyzed surgical tissues and talc containers for asbestos and talc.

RESULTS

Talc was found in all cases and tremolite and/or anthophyllite asbestos was found in 8/10 cases. The asbestos fibers found in the "cosmetic" talc containers matched those found in tissues. We estimated inhaled asbestos dose ranged from 0.38 to 5.18 fiber years.

CONCLUSION

We provide evidence that the inhaled dose of asbestos/fibrous talc from "cosmetic" talc use causes ovarian cancer. The unique combination of the types of asbestiform minerals detected in cancerous tissue and "cosmetic" talc is a fingerprint for exposure to asbestos-containing talc.

Incidence of Cancer and Asbestos-Related Diseases among Residents Living near Abandoned Asbestos Mines in South Korea: A Retrospective Cohort Study Using National Health Insurance Database

The use of asbestos has been banned since 2009 in South Korea. However, there is still a risk of exposure to environmental asbestos originating from abandoned asbestos mines. We constructed a retrospective dynamic cohort using the National Health Insurance Database of South Korea. We determined the risk of developing asbestos-related diseases (ARDs) among residents living near asbestos mines compared with those living in the control area and the general population. The risks of asbestosis (adjusted hazards ratio [HR] 65.40, 95% CI = 35.02-122.12) and pleural plaques (adjusted HR 3.55, 95% CI = 1.96-6.41) were significantly increased among residents living near the asbestos mines compared with the control area. The risk of malignant mesothelioma was increased near asbestos mines compared with the control area; however, it was not significant (adjusted HR 1.83, 95% CI = 0.61-5.47). When a separate analysis according to sex was conducted, the risk of mesothelioma among male residents was statistically significant (adjusted HR 8.30, 95% CI = 1.04-66.63), and the standardized incidence ratio (SIR) was significantly increased (SIR 3.48, 95% CI = 1.50-6.85). The risk of ARDs was increased due to environmental asbestos exposure near abandoned asbestos mines in South Korea.

Geographic study of mortality due to mesothelioma in Peru and its evolution

BACKGROUND

Peru has a public health problem because of asbestos imports. We analyzed the mortality trends for mesothelioma in Peru and its provinces from 2005 to 2014 and estimated their relationship with the amount of asbestos imported previously.

METHODS

We computed age-standardized mortality rates (ASMRs) per 100,000 population (direct method and SEGI world standard population reference), and the standardized mortality ratio (SMR). The relationship between the amount of asbestos imported annually along the period 1965-2010 and the number of mesothelioma deaths per year from 2005 to 2014 was estimated by log-linear Poisson regression models and Pearson correlation calculations.

RESULTS

After correcting the number of deaths, Peru registered 428 cases (or 430 when corrected cases are rounded by sex) between 2005 and 2014. The highest ASMRs were in Arequipa and Callao (range: 0.40-0.41/100,000 population), followed by Huancavelica (0.36/100,000 population). This translates into approximately one death per each 68-111 of asbestos tons imported. The latency period for the higher level of positive correlation found was 8 years (r = 0.8). Male female sex ratio was lower in provinces such as Junin and Hunacavelica with geological asbestos risk.

CONCLUSIONS

Two patterns of mesothelioma risk have been detected, occupational and environmental. During the 2002-2006 years, Peru increased the asbestos use. If crocidolite imports were also increased, this could be behind the 8 years latency period detected. Peru should boost strategies towards the total ban of all forms of asbestos.

Difficulties in establishing a causal link between chemical exposures and cancer cannot be overcome by court assessments

Scientific data are often used in lawsuits to prove, or dismiss, causation by a claimed factor of a claimed disease. Recent media reports of million-dollar compensations awarded to some cancer patients who had been exposed to certain chemical substances motivated me to examine how solid the causal links really were. Here, I discuss the limitations of epidemiological research on cancer causation and highlight how new knowledge of cancer genetics makes it unrealistic to expect that cancer causation can be clearly demonstrated. I then present two exposure-cancer cases, namely talcum powder-ovarian cancer and glyphosate-non-Hodgkin lymphoma, that led to civil lawsuits decided, in the United States, in favor of the claimants. Both these cancers have several risk factors, among which the claimed exposure presents only a minor, if any, increased risk. Through these cases, I explain why the use of epidemiological data is inappropriate to define causal associations in complex diseases like cancer. I close by suggesting a fairer approach, called proportional liability, to resolving future cancer litigation cases.

Association between pelvic inflammatory disease, infertility, ectopic pregnancy and the development of ovarian serous borderline tumor, mucinous borderline tumor and low-grade serous carcinoma

OBJECTIVE

Risk factors for ovarian borderline tumors and low-grade serous carcinoma (LGSC) are poorly understood. The aim of this study was to examine the association between infertility, pelvic inflammatory disease (PID), endometriosis, ectopic pregnancy, hysterectomy, tubal ligation and parity and the risk of serous borderline tumor (SBT), mucinous borderline tumor (MBT) and LGSC.

METHODS

This was a population-based cohort study using linked administrative and hospital data. Participants were 441,382 women born between 1945 and 1975 who had been admitted to hospital in Western Australia between 1 January 1980 and 30 June 2014. We used Cox regression to estimate hazard ratios (HRs).

RESULTS

We observed an increased rate of SBT associated with infertility, PID and ectopic pregnancy (HRs and 95% CIs were, respectively, 1.98 (1.20-3.26); 1.95 (1.22-3.10) and 2.44 (1.20-4.96)). We did not detect an association between any of the factors under study and the rate of MBT. A diagnosis of PID was associated with an increased rate of LGSC (HR 2.90, 95% CI 1.21-6.94).

CONCLUSIONS

The association with PID supports the hypothesis that inflammatory processes within the upper gynaecological tract and/or peritoneum may predispose to the development of SBT and LGSC.

Occurrence, behaviour, and human exposure pathways and health risks of toxic geogenic contaminants in serpentinitic ultramafic geological environments (SUGEs): A medical geology perspective

Serpentinitic ultramafic geological environments (SUGEs) contain toxic geogenic contaminants (TGCs). Yet comprehensive reviews on the medical geology of SUGEs are still lacking. The current paper posits that TGCs occur widely in SUGEs, and pose human health risks. The objectives of the review are to: (1) highlight the nature, occurrence and behaviour of TGCs associated with SUGEs; (2) discuss the human intake pathways and health risks of TGCs; (4) identify the key risk factors predisposing human health to TGCs particularly in Africa; and (5) highlight key knowledge gaps and future research directions. TGCs of human health concern in SUGEs include chrysotile asbestos, toxic metals (Fe, Cr, Ni, Mn, Zn, Co), and rare earth elements. Human intake of TGCs occur via inhalation, and ingestion of contaminated drinking water, wild foods, medicinal plants, animal foods, and geophagic earths. Occupational exposure may occur in the mining, milling, sculpturing, engraving, and carving industries. African populations are particularly at high risk due to: (1) widespread consumption of wild foods, medicinal plants, untreated drinking water, and geophagic earths; (2) weak and poorly enforced environmental, occupational, and public health regulations; and (3) lack of human health surveillance systems. Human health risks of chrysotile include asbestosis, cancers, and mesothelioma. Toxic metals are redox active, thus generate reactive oxygen species causing oxidative stress. Dietary intake of iron and geophagy may increase the iron overload among native Africans who are genetically predisposed to such health risks. Synergistic interactions among TGCs particularly chrysotile and toxic metals may have adverse human health effects. The occurrence of SUGEs, coupled with the several risk factors in Africa, provides a unique and ideal setting for investigating the relationships between TGCs and human health risks. A conceptual framework for human health risk assessment and mitigation, and future research direction are highlighted.

Geographic Co-Occurrence of Mesothelioma and Ovarian Cancer Incidence

Background: Asbestos is an established cause of several cancers, including mesothelioma and ovarian cancer. Incidence of mesothelioma, the sentinel asbestos-associated cancer, varies by state, likely reflecting different levels of asbestos exposure. We hypothesized that states with high mesothelioma incidence may also have high ovarian cancer incidence. Materials and Methods: Using data from the Centers for Disease Control and Prevention National Program for Cancer Registries and the National Cancer Institute Surveillance, Epidemiology, and End Results Program, we examined the geographic co-occurrence of mesothelioma and ovarian cancer incidence rates by U.S. state for 2003-2015. Results: By state, mesothelioma incidence ranged from 0.5 to 1.3 cases per 100,000 persons and ovarian cancer incidence ranged from 9 to 12 cases per 100,000 females. When states were grouped by quartile of mesothelioma incidence, the average ovarian cancer incidence rate was 10% higher in states with the highest mesothelioma incidence than in states with the lowest mesothelioma incidence. Ovarian cancer incidence tended to be higher in states with high mesothelioma incidence (Pearson correlation r = 0.54; p < 0.0001). Conclusions: Data from state cancer registries show ovarian cancer incidence was positively correlated with mesothelioma incidence, suggesting asbestos may be a common exposure. The potential for asbestos exposure has declined since the 1970s because fewer products contain asbestos; however, some products, materials, and buildings may still release asbestos and thousands of workers may be exposed. Ensuring that people are protected from exposure to asbestos in their workplaces, homes, schools, and communities may reduce the risk of several cancers.

Investigating the association between occupational exposure to asbestos and ovarian carcinoma: results from a pilot study in Germany

Background

The aim of this pilot study was to assess the feasibility of a large-scale epidemiologic investigation elucidating the quantitative association between occupational exposure to asbestos and ovarian cancer in former German asbestos workers.

Methods

Between December 2017 and May 2018, a random sample of one thousand insured woman registered at the health service of a German trade association as formerly occupationally exposed to asbestos were invited to participate in a pilot study. Participation included a phone interview using a standardised questionnaire. The feasibility of the project was evaluated using a priori defined criteria. They included response, number of cases, eligibility of the questionnaire data for exact estimation of asbestos fibre-years, and availability of relevant medical documentation (imaging procedures, medical reports, and histologic materials).

Results

The response (17%) was clearly below the intended number of 60%. With six tumour suspects, of which two could be confirmed by medical documents, the number of cases was within the expected range of two to eleven cases. Exact asbestos fibre-year estimations could be performed for 29% of all interviewees, but only for one suspected case. Medical documentation could be collected for only few participants, while no histology reports could be obtained for all cases. Thus, only the feasibility criterion of the expected number of cases was fulfilled.

Conclusion

The results of the pilot study indicate that the planned project is feasible only to a very limited extent. For further planning of the study, measures to improve recruitment of participants are necessary.

Exposure to asbestos and the risk of colorectal cancer mortality: a systematic review and meta-analysis

Asbestos exposure is associated with mesothelioma and cancer of the lung, larynx and ovary. However, the association between asbestos exposure and colorectal cancer is controversial despite several systematic reviews of the literature, including a number of meta-analyses. We performed a systematic review and meta-analysis to evaluate quantitatively the association between exposure to asbestos and colorectal cancer. We searched for articles on occupational asbestos exposure and colorectal cancer in PubMed, EMBASE and Web of Science published before April 2018. In total, 44 articles were selected and 46 cohort studies were analysed. The overall pooled risk estimates and corresponding 95% CIs of the association between occupational asbestos exposure and colorectal cancer were calculated using a random-effects model. Subgroup analyses and sensitivity tests were also performed. There was a significantly increased risk of colorectal cancer mortality among workers exposed to asbestos occupationally, with an overall pooled SMR of 1.16 (95% CI: 1.05 to 1.29). The pooled SMR for colorectal cancer was elevated in studies in which the asbestos-associated risk of lung cancer was also elevated (1.43; 95% CI: 1.30 to 1.56). This implies that the risk of colorectal cancer mortality increases as the level of asbestos exposure rises. A sensitivity analysis showed robust results and there was no publication bias. Although the effect size was small and the heterogeneity among studies was large, our findings indicate that occupational exposure to asbestos is a risk factor for colorectal cancer.

Exposure-based assessment and economic valuation of adverse birth outcomes and cancer risk due to nitrate in United States drinking water

BACKGROUND

Nitrate ingestion from drinking water has been associated with an increased risk of adverse birth outcomes as well as elevated risk of colorectal cancer and several other cancers. Yet, to date, no studies have attempted to quantify the health and economic impacts due to nitrate in drinking water in the United States.

METHODS

This study presents a first-of-its-kind comprehensive assessment of nitrate exposure from drinking water for the entire United States population. This exposure assessment serves as the basis for our analysis of the annual nitrate-attributable disease cases in the United States and the associated economic losses due to medical costs and lost productivity. Additionally, through a meta-analysis of studies on drinking water nitrate and colorectal cancer, we examine the exposure-response relationship for nitrate and cancer risk.

RESULTS

On the basis of national nitrate occurrence data and relative risk ratios reported in the epidemiology literature, we calculated that annually, 2939 cases of very low birth weight, 1725 cases of very preterm birth, and 41 cases of neural tube defects could be related to nitrate exposure from drinking water. For cancer risk, combining nitrate-specific risk estimates for colorectal, ovarian, thyroid, kidney, and bladder cancers results in a range of 2300 to 12,594 annual nitrate-attributable cancer cases (mean: 6537 estimated cases). For medical expenditures alone, this burden of cancer corresponds to an annual economic cost of 250 million to 1.5 billion U.S. dollars, together with a potential 1.3 to 6.5 billion dollar impact due to lost productivity. With the meta-analysis of eight studies of drinking water nitrate and colorectal cancer, we observed a statistically significant positive association for nitrate exposure and colorectal cancer risk and calculated a one-in-one million cancer risk level of 0.14 mg/L nitrate in drinking water.

CONCLUSION

Health and economic analyses presented here suggest that lowering exposure to nitrate in drinking water could bring economic benefits by alleviating the impacts of nitrate-associated diseases.

Cumulative asbestos exposure and mortality from asbestos related diseases in a pooled analysis of 21 asbestos cement cohorts in Italy

BACKGROUND

Despite the available information on cancer risk, asbestos is used in large areas in the world, mostly in the production of asbestos cement. Moreover, questions are raised regarding the shape of the dose response relation, the relation with time since exposure and the association with neoplasms in various organs. We conducted a study on the relationship between cumulative asbestos exposure and mortality from asbestos related diseases in a large Italian pool of 21 cohorts of asbestos-cement workers with protracted exposure to both chrysotile and amphibole asbestos.

METHODS

The cohort included 13,076 workers, 81.9% men and 18.1% women, working in 21 Italian asbestos-cement factories, with over 40 years of observation. Exposure was estimated by plant and period, and weighted for the type of asbestos used. Data were analysed with consideration of cause of death, cumulative exposure and time since first exposure (TSFE), and by gender. SMRs were computed using reference rates by region, gender and calendar time. Poisson regression models including cubic splines were used to analyse the effect of cumulative exposure to asbestos and TSFE on mortality for asbestos-related diseases. 95% Confidence Intervals (CI) were computed according to the Poisson distribution.

RESULTS

Mortality was significantly increased for 'All Causes' and 'All Malignant Neoplasm (MN)', in both genders. Considering asbestos related diseases (ARDs), statistically significant excesses were observed for MN of peritoneum (SMR: men 14.19; women 15.14), pleura (SMR: 22.35 and 48.10), lung (SMR: 1.67 and 1.67), ovary (in the highest exposure class SMR 2.45), and asbestosis (SMR: 507 and 1023). Mortality for ARDs, in particular pleural and peritoneal malignancies, lung cancer, ovarian cancer and asbestosis increased monotonically with cumulative exposure. Pleural MN mortality increased progressively in the first 40 years of TSFE, then reached a plateau, while peritoneal MN showed a continuous increase. The trend of lung cancer SMRs also showed a flattening after 40 years of TSFE. Attributable proportions for pleural, peritoneal, and lung MN were respectively 96, 93 and 40%.

CONCLUSIONS

Mortality for ARDs was associated with cumulative exposure to asbestos. Risk of death from pleural MN did not increase indefinitely with TSFE but eventually reached a plateau, consistently with reports from other recent studies.

Asbestos fiber identification in liver from cholangiocarcinoma patients living in an asbestos polluted area: a preliminary study

PURPOSE

To assess whether asbestos fibers may be observed in liver tissue of patients with cholangiocarcinoma (CC) with environmental or working asbestos exposure.

METHODS

Detection of fibers was performed directly on histologic sections of liver from 7 patients with CC using optical microscope and variable pressure scanning electron microscopy equipped with energy-dispersive spectroscopy (VP-SEM/EDS). All patients were from Casale Monferrato, Italy, a highly asbestos-polluted town. Due to ethical constraints, observers were blinded to patients' clinical features.

RESULTS

Fibers/bundles of fibers of chrysotile were detected in 5 out of 7 patients (71%). The boundary between healthy and neoplastic tissue or the fibrocollagen tissue produced by the neoplasia were identified as areas of fiber incorporation.

CONCLUSIONS

This study is the first report about the detection of chrysotile asbestos fibers in the liver of patients with CC. Further studies on larger cohorts are needed to corroborate our preliminary findings.

Does exposure to asbestos cause prostate cancer? A systematic literature review and meta-analysis

OBJECTIVE

The relationship between asbestos and prostate cancer (PCa) is not well understood due to small number of cases. This study aimed to determine the incidence and mortality of PCa among workers or residents exposed to asbestos based on a systematic review and meta-analysis METHODS: All published studies citing the standardized mortality ratio (SMR) or standardized incidence ratio (SIR) of PCa in workers or residents exposed to asbestos were collected by conducting a search on PubMed, EMBASE, Cochrane Library, and Web of Science before April 2018. Standardized mortality rate for PCa with its 95% confidence interval (CI) was pooled using a fixed-/random-effect model in STATA (Version14.0). This study is registered with PROSPERO, number CRD42018095195.

RESULTS

A total of 17 independent studies were included for the analysis. The overall pooled SMR of PCa was 1.22, with a 95% CI of 1.13 to 1.32, with no heterogeneity across the studies (I = 18.8%, P = .234). Subgroup analysis shows that exposure to crocidolite, cement, studies conducted in Europe and Oceania, and long study follow-up (≥25 years) all contribute to significantly higher SMR, and we found no evidence of publication bias (Begg test P value = .592, Egger test P value = .874).

CONCLUSIONS

This meta-analysis suggested that exposed to asbestos might be associated with an increased risk of PCa. High-exposure level of asbestos could contribute to significantly higher risk of PCa mortality.

Ex vivo detection and quantification of gold nanoparticles in human seminal and follicular fluids

Increasing consumption of engineered nanoparticles and occupational exposure to novel, ultrafine airborne particles during the last decades has coincided with deterioration of sperm parameters and delayed fecundity. In order to prevent possible adverse health effects and ensure a sustainable growth for the nanoparticle industry, the ability to investigate the nanosized, mineralogical load of human reproductive systems is becoming a real clinical need. Toward this goal, the current study proposes two methods for the detection and quantification of engineered nanoparticles in human follicular and seminal fluid, developed with the use of well-defined 60 nm Au particles. Despite the complexity of these biological fluids, simple physical and chemical treatments allow for the precise quantification of more than 50 and 70% wt of the spiked Au nanoparticles at low μg ml^-1 levels in follicular and seminal fluids, respectively. The use of electron microscopy for the detailed observation of the detected analytes is also enabled. The proposed method is applied on a small patient cohort in order to demonstrate its clinical applicability by exploring the differences in the metal and particulate content between patients with normal and low sperm count.

Ovarian cancer in a former asbestos textile factory worker: a case report

Background

The International Agency for Research on Cancer (IARC) defined that asbestos is a group 1 substance that causes lung cancer, mesothelioma (pleura and peritoneum), laryngeal cancer, and ovarian cancer in humans. Many studies on lung cancer, and mesothelioma caused by asbestos exposure have been conducted, but there was no case report of ovarian cancer due to asbestos exposure in Korea. We describe a case of ovarian cancer caused by asbestos exposure in a worker who worked at an asbestos textile factory for 3 years and 7 months in the late 1970s.

Case presentation

A 57-year-old woman visited the hospital because she had difficulty urinating. Ovarian cancer was suspected in radiologic examination, and exploratory laparotomy was performed. She was diagnosed with epithelial ovarian cancer. The patient did not undergo postoperative chemotherapy and recovered. She joined the asbestos factory in March 1976 and engaged in asbestos textile twisting and spinning for 1 year, 2 years and 7 months respectively. In addition, she lived near the asbestos factory for more than 20 years. There was no other specificity or family history.

Conclusion

Considering the patient’s occupational and environmental history, it is estimated that she had been exposed to asbestos significantly, so we determined that ovarian cancer in the patient is highly correlated with the occupational exposure of asbestos and environmental exposure is a possible cause as well. Social devices are needed to prevent further exposure to asbestos. It is also necessary to recognize that ovarian cancer can occur in workers who have previously been exposed to asbestos, and the education and social compensation for those workers are needed.

Occupational Burden of Asbestos-Related Diseases in Korea, 1998-2013: Asbestosis, Mesothelioma, Lung Cancer, Laryngeal Cancer, and Ovarian Cancer

BACKGROUND

Asbestos exposure causes asbestos-related diseases (ARDs) including asbestosis, malignant mesothelioma, lung cancer, laryngeal cancer, and ovarian cancer. Although Korea used substantial amounts of asbestos in the past, no study has focused on its occupational burden of disease (OBD). Therefore, this study aimed to determine the OBDs of ARDs in Korea.

METHODS

The CARcinogen Exposure (CAREX) database was used to determine the proportion of exposed population. Relative risks for lung cancer, laryngeal cancer, and ovarian cancer were used to determine the population-attributable fraction. Data for deaths caused by ARDs during 1998-2013 were obtained from the World Health Organization mortality database. The potential years of life lost (PYLL) and annual average PYLL (APYLL) indicated OBDs.

RESULTS

In Korea, the number of ARD-attributable deaths and PYLL due to all ARDs during 1998-2013 were 4,492 and 71,763.7, respectively. The number of attributable deaths and PYLL due to asbestosis, malignant mesothelioma, lung cancer, laryngeal cancer, and ovarian cancer were 37 and 554.2, 808 and 15,877.0, 3,256 and 47,375.9, 120 and 1,605.5, and 271 and 6,331.1, respectively; additionally, the APYLL were 15.0, 19.7, 14.6, 13.4, and 23.4, respectively, and the average age at death was 70.4, 62.6, 69.1, 69.9, and 61.8, respectively. Our study showed that although the use of asbestos has ceased in Korea, the incidence of ARDs tends to increase.

CONCLUSION

Therefore, efforts to reduce future OBDs of ARDs, including early detection and proper management of ARDs, are needed in Korea.

Occupational exposures and cancer: a review of agents and relative risk estimates

OBJECTIVES

The contribution of occupational exposures to the cancer burden can be estimated using population-attributable fractions, which is of great importance for policy making. This paper reviews occupational carcinogens, and presents the most relevant risk relations to cancer in high-income countries using France as an example, to provide a framework for national estimation of cancer burden attributable to occupational exposure.

METHODS

Occupational exposures that should be included in cancer burden studies were evaluated using multiple criteria: classified as carcinogenic or probably carcinogenic by the International Agency for Research on Cancer (IARC) Monographs volumes 1-114, being a primary occupational exposure, historical and current presence of the exposure in France and the availability of exposure and risk relation data. Relative risk estimates were obtained from published systematic reviews and from the IARC Monographs.

RESULTS

Of the 118 group 1 and 75 group 2A carcinogens, 37 exposures and 73 exposure-cancer site pairs were relevant. Lung cancer was associated with the most occupational carcinogenic exposures (namely, 18), followed by bladder cancer and non-Hodgkin's lymphoma. Ionising radiation was associated with the highest number of cancer sites (namely, 20), followed by asbestos and working in the rubber manufacturing industry. Asbestos, bis(chloromethyl)ether, nickel and wood dust had the strongest effect on cancer, with relative risks above 5.

CONCLUSIONS

A large number of occupational exposures continues to impact the burden of cancer in high-income countries such as France. Information on types of exposures, affected jobs, industries and cancer sites affected is key for prioritising policy and prevention initiatives.

Ovarian Cancer Incidence in the U.S. and Toxic Emissions from Pulp and Paper Plants: A Geospatial Analysis

Ovarian cancer is the fifth leading cause of female cancer mortality in the U.S. and accounts for five percent of all cancer deaths among women. No environmental risk factors for ovarian cancer have been confirmed. We previously reported that ovarian cancer incidence rates at the state level were significantly correlated with the extent of pulp and paper manufacturing. We evaluated that association using county-level data and advanced geospatial methods. Specifically, we investigated the relationship of spatial patterns of ovarian cancer incidence rates with toxic emissions from pulp and paper facilities using data from the Environmental Protection Agency’s Toxic Release Inventory (TRI). Geospatial analysis identified clusters of counties with high ovarian cancer incidence rates in south-central Iowa, Wisconsin, New York, Pennsylvania, Alabama, and Georgia. A bivariate local indicator of spatial autocorrelation (LISA) analysis confirmed that counties with high ovarian cancer rates were associated with counties with large numbers of pulp and paper mills. Regression analysis of state level data indicated a positive correlation between ovarian cancer and water pollutant emissions. A similar relationship was identified from the analysis of county-level data. These data support a possible role of water-borne pollutants from pulp and paper mills in the etiology of ovarian cancer.

Review on the adverse health effects of asbestiform antigorite, a non-regulated asbestiform serpentine mineral

BACKGROUND

Although antigorite is generally described as platy, its fibrous (asbestiform) variant is present widespread in serpentinite rocks. In addition to its primarily fibrous occurrence, asbestiform antigorite may also be formed from serpentinite with massive appearance during tunneling and mining. It is not of commercial interest, but exposure may occur in the certain environments.

METHODS AND RESULTS

Detailed studies of the structural features of this antigorite type revealed characteristics closely related to those of chrysotile. Therefore, it is plausible that this serpentine mineral may present a similar health risk for exposed subjects. This is in agreement with results from clinical and animal studies, as well as in vitro experiments showing the cytotoxic, fibrogenic, and carcinogenic potential of antigorite, similar to that of chrysotile and amphibole asbestos.

CONCLUSIONS

Current evidence supports a need for an update to existing regulations to include unregulated asbestiform antigorite, similar to regulatory measures taken for asbestos.

Cosmetics and Cancer: Adverse Event Reports Submitted to the Food and Drug Administration

There have been numerous controversies surrounding cosmetic products and increased cancer risk. Such controversies include associations between parabens and breast cancer, hair dyes and hematologic malignancies, and talc powders and ovarian cancer. Despite the prominent media coverage and numerous scientific investigations, the majority of these associations currently lack conclusive evidence. In 2016, the US Food and Drug Administration (FDA) made publically available all adverse event reports in Center for Food Safety and Applied Nutrition's Adverse Event Reporting System (CAERS), which includes complaints related to cosmetic products. We mined CAERS for cancer-related reports attributed to cosmetics. Between 2004 and 2017, cancer-related reports caused by cosmetics represented 41% of all adverse events related to cosmetics. This yielded 4427 individual reports of cancer related to a cosmetic product. Of these reports, the FDA redacted the specific product names in 95% of cancer-related reports under the Freedom of Information Act exemptions, most likely due to ongoing legal proceedings. For redacted reports, ovarian cancer reports dominated (n = 3992, 90%), followed by mesothelioma (n = 92, 2%) and malignant neoplasm unspecified (n = 46, 1%). For nonredacted reports, or those reports whose product names were not withheld (n = 218), 70% were related to ovarian cancer attributed to talc powders, followed by skin cancer (11%) and breast cancer (5%) attributed to topical moisturizers. Currently, CAERS is of limited utility, with the available data having been subjected to significant reporter bias and a lack of supportive information such as demographic data, medical history, or concomitant product use. Although the system has promise for safeguarding public health, the future utility of the database requires broader reporting participation and more complete reporting, paired with parallel investments in regulatory science and improved molecular methods.

Douching, Talc Use, and Risk of Ovarian Cancer

BACKGROUND

Douching was recently reported to be associated with elevated levels of urinary metabolites of endocrine disrupting phthalates, but there is no literature on douching in relation to ovarian cancer. Numerous case-control studies of genital talc use have reported an increased risk of ovarian cancer, but prospective cohort studies have not uniformly confirmed this association. Behavioral correlation between talc use and douching could produce confounding.

METHODS

The Sister Study (2003-2009) enrolled and followed 50,884 women in the US and Puerto Rico who had a sister diagnosed with breast cancer. At baseline, participants were asked about douching and talc use during the previous 12 months. During follow-up (median of 6.6 years), 154 participants reported a diagnosis of ovarian cancer. We computed adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for ovarian cancer risk using the Cox proportional hazards model.

RESULTS

There was little association between baseline perineal talc use and subsequent ovarian cancer (HR: 0.73, CI: 0.44, 1.2). Douching was more common among talc users (odds ratio: 2.1, CI: 2.0, 2.3), and douching at baseline was associated with increased subsequent risk of ovarian cancer (HR: 1.8, CI: 1.2, 2.8).

CONCLUSIONS

Douching but not talc use was associated with increased risk of ovarian cancer in the Sister Study.

Asbestos-Related Disorders in Germany: Background, Politics, Incidence, Diagnostics and Compensation

There was some limited use of asbestos at end of the 19th century in industrialized countries including Germany, but its consumption dramatically increased after World War II. The increase in use and exposure was followed by the discovery of high numbers of asbestos-related diseases with a mean latency period of about 38 years in Germany. The strong socio-political pressure from the asbestos industry, its affiliated scientists and physicians has successfully hindered regulatory measures and an asbestos ban for many years; a restrictive stance that is still being unravelled in compensation litigation. This national experience is compared with the situation in other industrialized countries and against the backdrop of the constant efforts of the WHO to eliminate asbestos-related diseases worldwide.

Asbestos fibre burden in gallbladder: A case study

The methods conventionally used to determine the burden of asbestos fibres inhaled/incorporated in lung require chemical digestion of the biological matrix before counting/characterising the inorganic fibrous phases under scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS). Asbestos fibres can also be present in extra-pulmonary organs, and we set out to quantify the fibres in gallbladder. Although the standardised procedure requires approximately 5 × 10^-1 g of wet tissue, this amount of tissue is not always available. We applied the procedure on about 9 × 10^-4 g of gallbladder from a patient with known environmental and workplace exposure to asbestos. The patient died of malignant pleural mesothelioma and was also affected by severe bile-tract problems. The traditional procedure of digesting tissue samples in NaClO and filtering the resulting suspension was carried out. The filter was then examined under SEM/EDS using two methods 1. following the standardised procedure to assess the fibre burden in lung by investigating only 2 mm² of the filter (660 microscopic fields), and 2. analysing all the microscopic fields in one-quarter of the filter (about 82 mm²). In parallel, histological sections (prepared in the usual way for medical diagnosis) were analysed without digestion or manipulation of the sample using variable pressure SEM/EDS. The fibre counts obtained using the two methods were of the same order of magnitude, i.e., ∼10⁵ fibres/g of wet tissue. We showed that the counting of fibres in human tissue may be successfully carried out even when a limited amount of tissue is available. We also found that, when exposure to asbestos is considerable, the number of asbestos fibres accumulating in the gallbladder may be significant.