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

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.

Air pollution and survival in patients with malignant mesothelioma and asbestos-related lung cancer: a follow-up study of 1591 patients in South Korea

BACKGROUND

Despite significant advancements in treatments such as surgery, radiotherapy, and chemotherapy, the survival rate for patients with asbestos-related cancers remains low. Numerous studies have provided evidence suggesting that air pollution induces oxidative stress and inflammation, affecting acute respiratory diseases, lung cancer, and overall mortality. However, because of the high case fatality rate, there is limited knowledge regarding the effects of air pollution exposures on survival following a diagnosis of asbestos-related cancers. This study aimed to determine the effect of air pollution on the survival of patients with malignant mesothelioma and asbestos-related lung cancer.

METHODS

We followed up with 593 patients with malignant mesothelioma and 998 patients with lung cancer identified as asbestos victims between 2009 and 2022. Data on five air pollutants-sulfur dioxide, carbon monoxide, nitrogen dioxide, fine particulate matter with a diameter < 10 μm, and fine particulate matter with a diameter < 2.5 μm-were obtained from nationwide atmospheric monitoring stations. Cox proportional hazard models were used to estimate the association of cumulative air pollutant exposure with patient mortality, while adjusting for potential confounders. Quantile-based g-computation was used to assess the combined effect of the air pollutant mixture on mortality.

RESULTS

The 1-, 3-, and 5-year survival rates for both cancer types decreased with increasing exposure to all air pollutants. The estimated hazard ratios rose significantly with a 1-standard deviation increase in each pollutant exposure level. A quartile increase in the pollutant mixture was associated with a 1.99-fold increase in the risk of malignant mesothelioma-related mortality (95% confidence interval: 1.62, 2.44). For lung cancer, a quartile increase in the pollutant mixture triggered a 1.87-fold increase in the mortality risk (95% confidence interval: 1.53, 2.30).

CONCLUSION

These findings support the hypothesis that air pollution exposure after an asbestos-related cancer diagnosis can negatively affect patient survival.

The Pleural Mesothelioma Cases and Mortality in Portugal in 2014-2020: A Descriptive Study

BACKGROUND

The incidence and mortality of pleural mesothelioma (PM) reflect the production and consumption of asbestos over time. However, despite the current global concern, these data remain to be known.

OBJECTIVE

Our aim was to carry out a descriptive analysis of PM cases and mortality from some Portuguese databases between 2014 and 2020.

METHODS

A retrospective observational study was carried out between 2014 and 2020. Data on the number of PM cases were provided by the Portuguese Cancer Registry, and data on mortality were from the Portuguese Death Certificate Information System.

RESULTS

Between 2014 and 2020, 315 cases of PM were reported, with 222 (70.5%) men. The average age of patients was 72.1, with the highest number of cases in patients aged >70 years (n = 198; 62.9%). The highest number of cases was reported in 2018 (n = 62; 19.7%). Regarding mortality, 169 deaths were reported, with 126 (74.6%) men and mostly in individuals aged >70 years (n = 109; 64.5%). It is estimated that around 520 years of potential life were lost. The highest number of deaths occurred in 2015 (n = 33; 19.5%).

CONCLUSION

It is mandatory to reinforce the need for surveillance programs that allow us to gather real and reliable data and eliminate asbestos-related diseases.

Issue 3-The occupational burden of respiratory diseases, an update

INTRODUCTION AND AIMS

Workplace exposures are widely known to cause specific occupational diseases such as silicosis and asbestosis, but they also can contribute substantially to causation of common respiratory diseases. In 2019, the American Thoracic Society (ATS) and the European Respiratory Society (ERS) published a joint statement on the occupational burden of respiratory diseases. Our aim on this narrative review is to summarise the most recent evidence published after the ATS/ERS statement as well as to provide information on traditional occupational lung diseases that can be useful for clinicians and researchers.

RESULTS

Newer publications confirm the findings of the ATS/ERS statement on the role of workplace exposure in contributing to the aetiology of the respiratory diseases considered in this review (asthma, COPD, chronic bronchitis, idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, infectious pneumonia). Except for COPD, chronic bronchitis and infectious pneumonia, the number of publications in the last 5 years for the other diseases is limited. For traditional occupational lung diseases such as silicosis and asbestosis, there are old as well as novel sources of exposure and their burden continues to be relevant, especially in developing countries.

CONCLUSIONS

Occupational exposure remains an important risk factor for airways and interstitial lung diseases, causing occupational lung diseases and contributing substantially in the aetiology of common respiratory diseases. This information is critical for public health professionals formulating effective preventive strategies but also for clinicians in patient care. Effective action requires shared knowledge among clinicians, researchers, public health professionals, and policy makers.

Metabolic Carcinogenesis

Several types of environmental, chemical and metabolic carcinogens exist both exogenously and endogenously. Humans are daily exposed to aforementioned carcinogens through various sources such as through water, air and food or through metabolic and inflammatory products. This chapter will summarize the links between exogenous and endogenous carcinogen exposure and their metabolism with the cancer pathogenesis and associated risks. This chapter will also cover the carcinogens acquired through lifestyle factors like tobacco use and occupational exposures to different chemicals like asbestos, arsenic, chloroform, vinyl chloride, etc. Moreover, environmental carcinogens such as radiation, sunlight, diet, smoke, etc. will also be discussed in this chapter. Furthermore, there are certain carcinogens that require bio-activation and various human enzymes that play a vital role in the metabolic carcinogenesis will also be recapitulated. Necessary preventive measures against carcinogenic exposure from the exogenous environment are significant to be taken into account to reduce the risks associated with the carcinogens.

Disease Latency according to Asbestos Exposure Characteristics among Malignant Mesothelioma and Asbestos-Related Lung Cancer Cases in South Korea

Korea was one of the major consumers of asbestos in the late 1900s, and asbestos-related disease patients have been reported continuously to date, owing to long disease latency. Several studies have been conducted to predict the future incidence of malignant mesothelioma and lung cancer in Korea, but little is understood about the latency time. Therefore, the aim of this study is to estimate the latency period of malignant mesothelioma and asbestos-related lung cancer in Korea and its determinants. We obtained information from the Environmental Health Centers for Asbestos in Korea on the history of asbestos exposure and demographic characteristics of 1933 patients with malignant mesothelioma and asbestos-related lung cancer. In our study, the latency periods for malignant mesothelioma and lung cancer were 33.7 and 40.1 years, respectively. Regardless of the disease type, those with a history of exposure related to the production of asbestos-containing products or asbestos factories had the shortest latency period. In addition, we observed that those who worked in or lived near asbestos mines tended to have a relatively long disease latency. Smoking was associated with shorter latency, but no linear relationship between the lifetime smoking amount (expressed in pack years) and latent time was observed. In addition, the age of initial exposure showed a negative linear association with the latency period for mesothelioma and lung cancer.

Mesothelioma and Colorectal Cancer: Report of Four Cases with Synchronous and Metachronous Presentation

There is evidence that asbestos could play a role in the carcinogenesis of digestive cancers. The presence of asbestos fibres in histological samples from gastric, biliary, colon cancers has been reported, but the mechanism is still controversial. It has been hypothesised that asbestos reaches these sites, especially through contaminated water; however, some experimental studies have shown that the inhaled fibres are mobile, so they can migrate to many organs, directly or via blood and lymph flow. We report four unusual cases of colorectal cancers in patients with a long history of asbestos exposure who also developed synchronous or metachronous mesothelioma. We evaluated the roles of BRCA associated protein-1 (BAP1) and cyclin-dependent kinase inhibitor 2A (CDKN2A) in colon cancer and mesothelioma to support the hypothesis that BAP-1 and CDKN2A are tumour suppressor genes involved in disease progression, recurrence, or death in both digestive cancers and mesothelioma. Potentially, these markers may be used as predictors of worse prognosis, but we also stress the importance of clinical surveillance of exposed patients because asbestos could induce cancer in any organ.

Asbestosis diagnosis algorithm combining the lung segmentation method and deep learning model in computed tomography image

BACKGROUND

Early detection of asbestosis is important; hence, quick and accurate diagnostic tools are essential. This study aimed to develop an algorithm that combines lung segmentation and deep learning models that can be utilized as a clinical decision support system (CDSS) for diagnosing patients with asbestosis in segmented computed tomography (CT) images.

METHODS

We accurately segmented the lungs in CT images of patients examined at Seoul St. Mary's Hospital using a threshold-based method. Lungs with asbestosis and normal lungs were classified by applying the segmented image to the long-term recurrent convolutional network deep learning model. Performance was evaluated using the area under the receiver operating characteristic curve (AUROC) and F1 score from the test data.

RESULTS

The algorithm developed using the DenseNet201pre-trained model showed excellent performance, with a sensitivity of 0.962, specificity of 0.975, accuracy of 0.970, AUROC of 0.968, and F1 score of 0.961.

CONCLUSIONS

We developed an algorithm with significantly better diagnostic accuracy than a radiologist (0.970 vs. 0.73-0.79). Our developed algorithm is expected to be an excellent support tool if used as a CDSS to diagnose asbestosis using CT images.

Using GIS to Estimate Population at Risk Because of Residence Proximity to Asbestos Processing Facilities in Colombia

The recent enactment of the law banning asbestos in Colombia raises a significant number of challenges. The largest factories that have historically processed asbestos include five asbestos-cement facilities located in the cities of Sibaté (Cundinamarca), Cali (Valle del Cauca), and Barranquilla (Atlántico), and Manizales (Caldas), which has two, as well as a friction products facility in Bogotá D.C. An asbestos chrysotile mine has also operated in Colombia since 1980 in Campamento (Antioquia). In the framework of developing the National Asbestos Profile for Colombia, in this study, we estimated the population residing in the vicinity of asbestos processing plants or the mine and, therefore, potentially at risk of disease. Using a geographic information system, demographic data obtained from the last two general population censuses were processed to determine the number of people living within the concentric circles surrounding the asbestos facilities and the mine. In previous studies conducted in different countries of the world, an increased risk of asbestos-related diseases has been reported for people living at different distance bands from asbestos processing facilities. Based on these studies, circles of 500, 1000, 2000, 5000, and 10,000 m radii, centered on the asbestos processing facilities and the mine that operated in Colombia, were combined with the census data to estimate the number of people living within these radii. Large numbers of people were identified. It is estimated that in 2005, at the country level, 10,489 people lived within 500 m of an asbestos processing facility or mine. In 2018, and within a distance of 10,000 m, the number of people was 6,724,677. This information can aid public health surveillance strategies.

Laryngeal Squamous Cell Carcinoma: Clinical Significance and Potential Mechanism of Cell Division Cycle 45

Background: Cell division cycle 45 (CDC45) plays an important role in the occurrence and development of numerous carcinomas, but its effect in laryngeal squamous cell carcinoma (LSCC) remains unclear. Materials and Methods: The messenger RNA and protein expression levels of CDC45 in LSCC were evaluated with a t test and the standard mean difference (SMD). The ability of CDC45 expression to distinguish the LSCC was assessed through receiver operating characteristic (ROC) curves. Gene set enrichment analysis (GSEA), protein-protein interaction, public databases, and online tools were used to explore the potential molecular mechanism of CDC45 in LSCC. Results: A high expression of CDC45 was identified in LSCC (SMD = 2.61, 95% confidence interval [1.62-3.61]). Through ROC curves, the expression of CDC45 makes it feasible to distinguish the LSCC group from the non-LSCC counterpart. CDC45 was relevant to the progression-free interval of LSCC patients (log-rank p = 0.03). GSEAs show that CDC45 is related to the cell cycle. CDC45, CDC6, KIF2C, and AURKB were identified as hub genes of LSCC. E2F1 may be the regulatory transcription factor of CDC45. Conclusions: High expression of CDC45 likely demonstrates carcinogenic effects in LSCC, and CDC45 is a potential target in screening and treatment of LSCC.

Standardized Incidence Ratio and Standardized Mortality Ratio of Malignant Mesothelioma in a Worker Cohort Using Employment Insurance Database in Korea

Malignant mesothelioma is one of the appropriate indicators for assessing the carcinogenic effects of asbestos. This study compared the risk ratio of mesothelioma according to the industry in the worker cohort. A cohort was constructed using the Korean employment insurance system during 1995–2017, enrolling 13,285,895 men and 10,452,705 women. The standardized mortality ratio (SMR) and standardized incidence ratio (SIR) were calculated using the indirect standardization method. There were 641 malignant mesotheliomas that occurred; the SIR was significantly higher than the general population (men 1.36, 95% confidence interval (CI) 1.24–1.48, women 1.44, 95% CI: 1.23–1.7). More than half (52.8%) of malignant mesothelioma cases occurred in the manufacturing (n = 240, 38.6%, SIR: men, 1.72, 95% CI: 1.37–2.15, women, 3.31, 95% CI: 1.71–5.79) and construction industries (n = 88, 14.2%, SIR: men, 1.54 95% CI: 1.33–1.78, women, 1.62 95% CI: 1.25–2.11). The accommodation and food service (men, 2.56 95% CI: 1.28–4.58, women 1.35, 95% CI: 0.65–2.48) and real estate (men 1.34, 95% CI: 0.98–1.83, women 1.95, 95% CI: 0.78–4.02) also showed a high SIR, indicating the risk of asbestos-containing materials in old buildings. The incidence of malignant mesothelioma is likely to increase in the future, given the long latency of this disease. Moreover, long-term follow-up studies will be needed.

Disease Burden and Attributable Risk Factors of Ovarian Cancer From 1990 to 2017: Findings From the Global Burden of Disease Study 2017

Aim: We aimed to estimate the disease burden and risk factors attributable to ovarian cancer, and epidemiological trends at global, regional, and national levels.

Methods: We described ovarian cancer data on incidence, mortality, and disability-adjusted life-years as well as age-standardized rates from 1990 to 2017 from the Global Health Data Exchange database. We also estimated the risk factors attributable to ovarian cancer deaths and disability-adjusted life-years. Measures were stratified by region, country, age, and socio-demographic index. The estimated annual percentage changes and age-standardized rates were calculated to evaluate temporal trends.

Results: Globally, ovarian cancer incident, death cases, and disability-adjusted life-years increased by 88.01, 84.20, and 78.00%, respectively. However, all the corresponding age-standardized rates showed downward trends with an estimated annual percentage change of −0.10 (−0.03 to 0.16), −0.33 (−0.38 to −0.27), and −0.38 (−0.32 to 0.25), respectively. South and East Asia and Western Europe carried the heaviest disease burden. The highest incidence, deaths, and disability-adjusted life-years were mainly in people aged 50–69 years from 1990 to 2017. High fasting plasma glucose level was the greatest contributor in age-standardized disability-adjusted life-years rate globally as well as in all socio-demographic index quintiles and most Global Disease Burden regions. Other important factors were high body mass index and occupational exposure to asbestos.

Conclusion: Our study provides valuable information on patterns and trends of disease burden and risk factors attributable to ovarian cancer across age, socio-demographic index, region, and country, which may help improve the rational allocation of health resources as well as inform health policies.

The Epidemiologic Characteristics of Malignant Mesothelioma Cases in Korea: Findings of the Asbestos Injury Relief System from 2011-2015

(1) Background: The purpose of this study was to investigate the epidemiological characteristics of malignant mesothelioma in Korea by investigating cases compensated under the asbestos injury relief system. (2) Methods: A total of 407 compensated cases between 2011 and 2015 were reviewed using medical records and resident registrations in order to investigate the dates of diagnosis and death. Asbestos exposure and patients’ general characteristics were investigated through face-to-face interviews. The standardized incidence ratio was calculated as the number of observations from 2005 to 2014 per exposure region in Korea, using the mid-annual population of each region in 2009 as the standard population. (3) Results: Among the 407 cases, 65.1% were male. The pleura and peritoneum were affected in 76.9% and 23.1% of cases, respectively. For peritoneal mesothelioma, the median survival duration was longer (p = 0.005), and the proportion of affected women was higher than that in pleural mesothelioma. The standardized incidence ratio (95% CI) by province of primary exposure was Chungnam 3.33 (2.51–4.35), Ulsan 1.85 (0.97–3.21), and Seoul 1.32 (1.06–1.63). (4) Conclusions: Although the representativeness of the data is limited, it is sufficient to assume the epidemiologic characteristics of malignant mesothelioma, help improve the compensation system, and contribute to future policies.

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.

The underlying molecular mechanism and identification of transcription factor markers for laryngeal squamous cell carcinoma

The screening and treatment of laryngeal squamous cell carcinoma (LSCC) still perplexes clinicians, making it necessary to explore new markers. To this end, this research examined the underlying molecular mechanism of LSCC based on high-throughput datasets (n = 249) from multiple databases. It also identified transcription factors (TFs) independently associated with LSCC prognosis. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, differential expression genes of LSCC were deemed relevant to the extracellular matrix and its related structures or pathways, suggesting that the extracellular matrix plays an important role in LSCC. At the same time, several hub genes that may also have important roles in LSCC were identified via protein–protein interaction analysis, including CDC45, TPX2, AURKA, KIF2C, NUF, MUC1, MUC7, MUC4, MUC15, and MUC21. Eight unreported LSCC prognostic TFs – BCAT1, CHD4, FOXA2, GATA6, HNF1A, HOXB13, MAFF, and TCF4 – were screened via Kaplan–Meier curves. Cox analysis determined for the first time that HOXB13 expression and gender were independently associated with LSCC prognosis. Compared to control tissues, elevated expression of HOXB13 was found in LSCC tissues (standardized mean difference = 0.44, 95% confidence interval [0.13–0.76]). HOXB13 expression also makes it feasible to screen LSCC from non-LSCC (area under the curve = 0.77), and HOXB13 may play an essential role in LSCC by regulating HOXB7. In conclusion, HOXB13 may be a novel marker for LSCC clinical screening and treatment.

Sex Difference and Smoking Effect of Lung Cancer Incidence in Asian Population

Simple Summary

This study analyzed the sex difference in the effect of smoking exposure on lung cancer in terms of absolute and relative risks despite the increasing lung cancer incidence in Asian female never smokers. Lung cancer risk is positively associated with the duration of smoking, quantity of smoking, and pack-years of smoking, and negatively associated with the number of years since smoking cessation for both sexes. However, higher lung cancer incidence in men than in women with the same level of smoking exposure was observed, suggesting a higher susceptibility for lung cancer in men. Sex should be considered in combination with smoking history in the selection of a lung cancer screening target population.

Abstract

This study analyzed the sex difference in the effect of smoking exposure on lung cancer in terms of absolute and relative risks despite the increasing lung cancer incidence in Asian female never smokers. A retrospective cohort study was conducted on individuals aged 40–79 years who participated in the national health screening program in 2007 and 2008 with linkage to the Korea Central Cancer Registry records. We evaluated sex differences in the age-standardized incidence rate (ASR) of lung cancer by smoking history and the hazard ratio (HR) after adjusting for potential confounders. ASRs for male and female never smokers were 92.5 and 38.3 per 100,000 person-years, respectively (rate ratio (RR) = 2.4; 95% confidence interval (CI) = 2.3–2.5). ASRs for male and female current smokers with a 30 pack-year smoking history were 305.3 and 188.4 per 100,000 person-years, respectively (RR = 1.6; 95% CI = 1.3–2.0). Smoking was significantly associated with lung cancer risk for both sexes. HRs for former smokers versus never smokers were 1.27 (95% CI = 1.23–1.33) for men and 1.43 (95% CI = 1.16–1.81) for women. HRs for current smokers versus never smokers were 2.71 (95% CI = 2.63–2.79) for men and 2.70 (95% CI = 2.48–2.94) for women. HRs for lung cancer increased similarly in both men and women according to smoking status. However, among Korean individuals with comparable smoking statuses, lung cancer incidence is higher in men than in women. Sex should be considered in combination with smoking history in the selection of a lung cancer screening target population.

Laryngeal Squamous Cell Carcinoma: Potential Molecular Mechanism and Prognostic Signature Based on Immune-Related Genes

BACKGROUND Immune-related genes (IRGs) are closely related to the incidence and progression of tumors, potentially indicating that IRGs play an important role in laryngeal squamous cell carcinoma (LSCC). MATERIAL AND METHODS An RNA sequencing dataset containing 123 samples was collected from The Cancer Genome Atlas. Based on immune-related differentially expressed genes (IRDEGs), a potential molecular mechanism of LSCC was explored through analysis of information in the Gene Ontology (GO) resource and the Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interactions (PPIs). A regulatory network of transcriptional regulators and IRDEGs was constructed to explore the underlying molecular mechanism of LSCC at the upstream level. Candidates from IRDEGs for signature were screened via univariate Cox analysis and using the least absolute shrinkage and selection operator (LASSO) technique. The IRDEG signature of LSCC was constructed by using a multivariate Cox proportional hazards model. RESULTS GO and KEGG analysis showed that IRDEGs may participate in the progression of LSCC through immune-related reactions. PPI analysis demonstrated that, among the IRDEGs in LSCC, the Kininogen 1; C-X-X motif chemokine ligand 10; elastase, neutrophil expressed; and LYZ genes are hub genes in the development of LSCC. At the upstream level, SPI1, SP140, signal transducer and activator of transcription 4, zinc finger E-box binding homeobox, and Ikaros family zinc finger 2 are the hub transcriptional regulators of IRDEGs. The risk score based on the IRDEG signature was able to distinguish prognosis in patients with LSCC and represents an independent prognostic risk factor for LSCC. CONCLUSIONS From the perspective of IRGs, we first constructed an IRDEG signature related to the prognosis of LSCC, which can be used as a novel marker to predict prognosis in patients with LSCC.

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.

Prostate Cancer and Asbestos: A Systematic Review and Meta-Analysis

INTRODUCTION

Asbestos-related diseases and cancers represent a major public health concern.

OBJECTIVE

To conduct a systematic review and meta-analysis to demonstrate that asbestos exposure increases the risk of prostate cancer.

METHODS

The PubMed, Cochrane Library, Embase, and ScienceDirect databases were searched using the keywords (prostate cancer OR prostatic neoplasm) AND (asbestos* OR crocidolite* OR chrysotile* OR amphibole* OR amosite*). To be included, articles needed to describe our primary outcome: Risk of prostate cancer after any asbestos exposure.

RESULTS

We included 33 studies with 15,687 cases of prostate cancer among 723,566 individuals. Asbestos exposure increased the risk of prostate cancer (effect size = 1.10, 95% confidence interval [CI] = 1.05-1.15). When we considered mode of absorption, respiratory inhalation increased the risk of prostate cancer (1.10, 95% CI = 1.05-1.14). Both environmental and occupational exposure increased the risk of prostate cancer (1.25, 95% CI = 1.01-1.48; and 1.07, 1.04-1.10, respectively). For type of fibers, the amosite group had an increased risk of prostate cancer (1.12, 95% CI = 1.05-1.19), and there were no significant results for the chrysotile/crocidolite group. The risk was higher in Europe (1.12, 95% CI = 1.05-1.19), without significant results in other continents.

DISCUSSION

Asbestos exposure seems to increase prostate cancer risk. The main mechanism of absorption was respiratory. Both environmental and occupational asbestos exposure were linked to increased risk of prostate cancer.

CONCLUSION

Patients who were exposed to asbestos should possibly be encouraged to complete more frequent prostate cancer screening.

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.

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.