Stomach cancer and occupational exposure to asbestos: a meta-analysis of occupational cohort studies

Discovery of the Natural Bibenzyl Compound Erianin in Dendrobium Inhibiting the Growth and EMT of Gastric Cancer through Downregulating the LKB1-SIK2/3-PARD3 Pathway

Erianin, a bibenzyl compound found in dendrobium extract, has demonstrated broad anticancer activity. However, its mechanism of action in gastric cancer (GC) remains poorly understood. LKB1 is a tumor-suppressor gene, and its mutation is an important driver of various cancers. Yet some studies have reported contradictory findings. In this study, we combined bioinformatics and in vitro and in vivo experiments to investigate the effect and potential mechanism of Erianin in the treatment of GC. The results show that LKB1 was highly expressed in patients' tumor tissues and GC cells, and it was associated with poor patient prognosis. Erianin could promote GC cell apoptosis and inhibit the scratch repair, migration, invasion, and epithelial-mesenchymal transition (EMT) characteristics. Erianin dose-dependently inhibited the expression of LKB1, SIK2, SIK3, and PARD3 but had no significant effect on SIK1. Erianin also inhibited tumor growth in CDX mice model. Unexpectedly, 5-FU also exhibited a certain inhibitory effect on LKB1. The combination of Erianin and 5-FU significantly improved the anti-tumor efficacy of 5-FU in the growth of GC cells and xenograft mouse models. In summary, Erianin is a potential anti-GC compound that can inhibit GC growth and EMT properties by targeting the LKB1-SIK2/3-PARD3-signaling axis. The synergistic effect of Erianin and 5-FU suggests a promising therapeutic strategy for GC treatment.

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.

Risk Factors of Gastric Cancer and Lifestyle Modification for Prevention

Gastric cancer has been consistently decreasing worldwide, whereas cardia gastric cancer is on the rise. This indicates that the exposure rates to epidemiological causes are changing. In this study, we aim to review the risk factors for gastric cancer with respect to cardia and non-cardia types. One of the most significant risk factors for gastric cancer is Helicobacter pylori infection. H. pylori infection is known as a risk factor for non-cardia gastric cancer, and there have been results indicating that H. pylori infection is not associated with cardia gastric cancer. However, in the East Asian region, there is epidemiological evidence suggesting that H. pylori infection might be a risk factor for cardia gastric cancer. Smoking and alcohol consumption are known risk factors for gastric cancer, regardless of anatomical location. Obesity is considered a factor in the development of cardia gastric cancer. However, further research is needed to understand the specific relationship with non-cardia gastric cancer. The consumption of high-salt and processed meat is more distinctly associated with non-cardia gastric cancer than in cardia gastric cancer. In addition to these factors, exposure to chemicals and radiation are considered risk factors for gastric cancer. Primary prevention of gastric cancer involves eliminating or avoiding risk factors such as H. pylori eradication and adopting a healthy lifestyle, including quitting smoking, reducing alcohol consumption, maintaining a healthy weight, and having a low-salt diet.

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.

Asbestos exposure and small cell lung cancer: Systematic review and meta-analysis

Asbestos is a mineral that is carcinogenic to humans. Its use has been banned in many occidental countries yet it is still produced in the United States, and materials that contain asbestos remain in many occupational settings and indoor environments. Even though asbestos carcinogenicity is well known, there is scant literature on its specific effects regarding small cell lung cancer (SCLC). We therefore conducted a systematic review and meta-analysis to determine SCLC risk among workers exposed to asbestos. A systematic search of the literature was conducted to identify studies which reported occupational exposure to asbestos and SCLC-related deaths and/or incidence. We identified seven case-control studies that included 3,231 SCLC cases; four studies reported smoking-adjusted risks. A significantly increased risk of SCLC (pooled OR 1.89; 95% CI, 1.25-2.86) was observed on pooling studies on men (six studies) that displayed moderate heterogeneity (I2 = 46.0%). Overall, our synthesis suggests that occupational exposure to asbestos significantly increases the risk of SCLC on men.

Mobility of crocidolite asbestos in sandy porous media mimicking aquifer systems

Asbestos is widely recognized as being a carcinogen when dispersed in air, but very little is known about its exposure pathways in water and its subsequent effects on human health. Several studies have proved asbestos presence in groundwater but failed to assess its mobility in aquifer systems. This paper aims to fill this gap by studying the transport of crocidolite, an amphibole asbestos, through sandy porous media mimicking different aquifer systems. To this purpose, two sets of column test were performed varying the crocidolite suspension concentration, the quartz sand grain size distribution, and the physicochemical water parameters (i.e., pH). The results proved that crocidolite is mobile in quartz sand due to the repulsive interactions between fibres and porous media. The concentration of fibres at the outlet of the column were found to decrease when decreasing the grain size distribution of the porous medium, with a bigger impact on highly concentrated suspensions. In particular, 5-to-10-µm-long fibres were able to flow through all the tested sands while fibres longer than 10 µm were mobile only through the coarser medium. These results confirm that groundwater migration should be considered a potential exposure pathway while implementing human health risk assessment.

Duration-response association between occupational exposure and pancreatic cancer risk: meta-analysis

BACKGROUND

Evidence is lacking on the occupational exposure time window to chemical agents related to pancreatic cancer risk.

AIMS

This study performed meta-regression and meta-analysis to examine the dose-response association between occupational exposure duration to chemical agents and pancreatic cancer risk.

METHODS

We searched and reviewed studies on exposure duration and pancreatic cancer in five databases (Cochrane Library, EMBASE, PubMed, ScienceDirect and Web of Science) from inception to 16 May 2022. Exposure refers to the years a worker was exposed to any chemical agent, and outcome variables were pancreatic cancer incidence and mortality.

RESULTS

We identified 31 studies, including 288 389 participants. In the meta-regression, the positive dose-response association indicated pancreatic cancer risk increased slightly with every additional year of exposure duration (slope = 1.01; 95% confidence interval [CI] 1.00-1.02). Pancreatic cancer risk increased with an exposure duration of 1-10 (relative risk [RR] = 1.04; 95% CI 1.02-1.06), 11-20 (RR = 1.11; 95% CI 1.05-1.16), and 21-30 years (RR = 1.39; 95% CI 1.12-1.73).

CONCLUSIONS

Pancreatic cancer risk increased as occupational exposure duration increased, with an exposure time window ranging from 1 to 30 years.

Updates on global epidemiology, risk and prognostic factors of gastric cancer

Gastric cancer (GC) is defined as the primary epithelial malignancy derived from the stomach, and it is a complicated and heterogeneous disease with multiple risk factors. Despite its overall declining trend of incidence and mortality in various countries over the past few decades, GC remains the fifth most common malignancy and the fourth leading cause of cancer-related death globally. Although the global burden of GC has shown a significant downward trend, it remains severe in certain areas, such as Asia. GC ranks third in incidence and mortality among all cancer types in China, and it accounts for nearly 44.0% and 48.6% of new GC cases and GC-related deaths in the world, respectively. The regional differences in GC incidence and mortality are obvious, and annual new cases and deaths are increasing rapidly in some developing regions. Therefore, early preventive and screening strategies for GC are urgently needed. The clinical efficacies of conventional treatments for GC are limited, and the developing understanding of GC pathogenesis has increased the demand for new therapeutic regimens, including immune checkpoint inhibitors, cell immunotherapy and cancer vaccines. The present review describes the epidemiology of GC worldwide, especially in China, summarizes its risk and prognostic factors, and focuses on novel immunotherapies to develop therapeutic strategies for the management of GC patients.

Gastric cancer incidence trends in China and Japan from 1990 to 2019: Disentangling age-period-cohort patterns

BACKGROUND

Recent data have shown divergent trends in gastric cancer (GC) incidence between China and Japan; however, the cause for has not been explored.

METHODS

We retrieved GC incidence data from 1990 to 2019 from the Global Burden of Disease study, stratified by sex for both countries. We analyzed annual average percentage change (AAPC) via a joinpoint regression model and estimated the effects of age, period, and cohort via the age-period-cohort model.

RESULTS

The age-standardized incidence rate trends for GC decreased in both countries and both sexes, but the reduction was more pronounced in Japan because the AAPC for Japanese males (AAPC = -2.65%; 95% CI, -2.98 to -2.32) was eight times greater than that of Chinese males (AAPC = -0.30%; 95% CI, -0.5 to -0.09). The age and cohort effects on the trend are similar in both countries: the risk of GC incidence increased with age among the Chinese and the Japanese but was lower among younger birth cohorts. The two countries showed contrasting trends over the study period; although the risk of GC rapidly decreased for Japanese males and females, it increased by twofold among Chinese males.

CONCLUSIONS

The period effect is the main reason for the divergent trends in age-standardized incidence rate for GC in China and Japan. By comparing national cancer control programs in both countries, we concluded that countries with a high prevalence of GC, such as China, can learn from Japan's experience in controlling GC by actively conducting national population screening, which is expected to facilitate both prevention and treatment of GC.

LAY SUMMARY

More than one-half of all new gastric cancer (GC) worldwide occur in China and Japan, but the reasons for the different incidence trends have not been thoroughly analyzed. Analysis using the age-period-cohort model confirmed that the cohort effect was the main reason for the decline in age-standardized incidence rate (ASIR) for GC and that the period effect may be the main reason for the divergent trends in gastric cancer ASIR in China and Japan.

Cancer Incidence and Risk of Multiple Cancers after Environmental Asbestos Exposure in Childhood-A Long-Term Register-Based Cohort Study

OBJECTIVES

To examine the asbestos-associated cancer incidence and the risk of multiple cancers in former school children exposed to environmental asbestos in childhood.

METHODS

A cohort of 12,111 former school children, born 1940-1970, was established using 7th grade school records from four schools located at a distance of 100-750 m in the prevailing wind direction from a large asbestos-cement plant that operated from 1928 to 1984 in Aalborg, Denmark. Using the unique Danish personal identification number, we linked information on employments, relatives' employments, date of cancer diagnosis, and type of cancer and vital status to data on cohortees extracted from the Supplementary Pension Fund Register (employment history), the Danish Cancer Registry, and the Danish Civil Registration System. We calculated standardized incidence rates (SIRs) for asbestos-associated cancers, all cancers, and multiple cancers using rates for a gender and five-year frequency-matched reference cohort.

RESULTS

The overall incidence of cancer was modestly increased for the school cohort (SIR 1.07, 95% confidence interval (CI) 1.02-1.12) compared with the reference cohort. This excess was driven primarily by a significantly increased SIR for malignant mesothelioma (SIR 8.77, 95% CI 6.38-12.05). Former school children who had combined childhood environmental and subsequent occupational exposure to asbestos had a significantly increased risk of lung cancer. Within this group, those with additional household exposure by a relative had a significantly increased SIR for cancer of the pharynx (SIR 4.24, 95% CI 1.59-11.29). We found no significant difference in the number of subjects diagnosed with multiple cancers between the two cohorts.

CONCLUSIONS

Our study confirms the strong association between environmental asbestos exposure and malignant mesothelioma and suggests that environmental asbestos exposure in childhood may increase the overall cancer risk later in life.

Effect of Ranitidine Intake on the Risk of Gastric Cancer Development

Gastric cancer is one of the most prevalent cancers globally, with high mortality, particularly in East Asia. Certain ranitidine products contain potentially carcinogenic N-nitrosodimethylamine. We investigated the potential association between gastric cancer risk and ranitidine intake using a nationwide cohort, extracted from the Korean National Health Insurance Service. In this longitudinal study, we employed a 1:1 propensity score matching according to sociodemographic factors. A total of 40,887 subjects were enrolled, of which 906 developed gastric cancer during the follow-up period. We investigated gastric cancer events during the follow-up period using the survival analysis, log-rank test, and Cox proportional hazards regression models to estimate incidence, survival rate, and hazard ratio. The incidence of gastric cancer was 67,422; 67,470; and 67,444 person-years in the control, other histamine-2 blockers, and ranitidine groups, respectively. Because the adjusted hazard ratio of gastric cancer was 0.98 and 1.01 in the other histamine-2 blockers and ranitidine groups, respectively, we could not calculate the likelihood of gastric cancer development in the ranitidine group. Ranitidine intake did not significantly increase the incidence of gastric cancer. Therefore, the relative risk of gastric cancer may be low in patients taking ranitidine products in South Korea.

Increased Risk of Gastric Cancer in Asbestos-Exposed Workers: A Retrospective Cohort Study Based on Taiwan Cancer Registry 1980-2015

Asbestos has been recognized as a human carcinogen associated with malignant mesothelioma, cancers of lung, larynx, and ovary. However, a putative association between gastric cancer and asbestos exposure remains controversial. In this study, we aimed to explore gastric cancer risk of workers potentially exposed to asbestos in Taiwan. The asbestos occupational cohort was established from 1950 to 2015 based on the Taiwan Labor Insurance Database, and Taiwan Environmental Protection Agency regulatory datasets, followed by the Taiwan Cancer Registry for the period 1980–2015. Standardized incidence ratios (SIRs) for cancer were computed for the whole cohort using reference rates of the general population, and also reference labor population. Compared with the general population, SIR of the asbestos occupational cohort for the gastric cancer increased both in males (1.05, 95% confidence interval (CI): 1.02–1.09) and females (1.10, 95% CI: 1.01–1.18). A total of 123 worksites were identified to have cases of malignant mesothelioma, where increased risk for gastric cancer was found with a relative risk of 1.76 (95% CI: 1.63–1.90). This 35-year retrospective cohort study of asbestos-exposed workers in Taiwan may provide support for an association between occupational exposure to asbestos and gastric cancer.

Global Incidence and Mortality of Gastric Cancer, 1980-2018

IMPORTANCE

Gastric cancer is one of the most common cancers, with a high mortality-to-incidence ratio. It is uncertain whether developed nations may encounter an increasing burden of gastric cancer in young adults, as occurs for other cancers.

OBJECTIVES

To evaluate the incidence and mortality of gastric cancer and compare the global incidence trends between younger (<40 years) and older (≥40 years) populations.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study analyzed data from global and national cancer registries, including data from 1980 to 2018, with at least 15 calendar years of incidence and mortality data. Data on age-standardized incidence and mortality rates of gastric cancer among 48 countries were retrieved from the Surveillance, Epidemiology, and End Results Program, the National Cancer Institute, the Nordic Cancer Registries, and the World Health Organization Mortality Database. The 10-year incidence trend of gastric cancer was assessed by age and sex. The 2018 GLOBOCAN database was used for reporting the global incidence and mortality of gastric cancer, the most recent data available at the time of analysis. Analyses were performed between January 10, 2020, and March 20, 2020.

MAIN OUTCOMES AND MEASURES

The average annual percent change (AAPC) of the incidence and mortality trends as evaluated by joinpoint regression analysis.

RESULTS

A total of 1 033 701 new cases of gastric cancer and 782 685 related deaths were reported in 2018. Overall, the incidence of gastric cancer decreased in 29 countries, and mortality decreased in 41 countries. The age-standardized incidence of gastric cancer decreased from a range of 2.6 to 59.1 in 1980 to a range of 2.5 to 56.8 in 2018 per 100 000 persons. The overall age-standardized mortality rate changed from a range of 1.3 to 25.8 in 1980 to a range of 1.5 to 18.5 in 2018 per 100 000 persons, but increasing mortality was observed in Thailand (female: AAPC, 5.30; 95% CI, 4.38-6.23; P < .001; male: AAPC, 3.92; 95% CI, 2.14-5.74; P < .001). The incidence of gastric cancer decreased in most regions among individuals 40 years or older and increased in populations younger than 40 years in several countries, including Sweden (male: AAPC, 13.92; 95% CI, 7.16-21.11; P = .001), Ecuador (female: AAPC, 6.05; 95% CI, 1.40-10.92; P = .02), and the UK (male: AAPC, 4.27; 95% CI, 0.15-8.55; P = .04; female: AAPC, 3.60; 95% CI, 3.59-3.61; P < .001).

CONCLUSIONS AND RELEVANCE

In this population-based cohort study, an increasing incidence of gastric cancer was observed in younger individuals in some countries, highlighting the need for more preventive strategies in younger populations. Future research should explore the reasons for these epidemiologic trends.

Risk of gastric cancer in the environs of industrial facilities in the MCC-Spain study

BACKGROUND

Gastric cancer is the fifth most frequent tumor worldwide. In Spain, it presents a large geographic variability in incidence, suggesting a possible role of environmental factors in its etiology. Therefore, epidemiologic research focused on environmental exposures is necessary.

OBJECTIVES

To assess the association between risk of gastric cancer (by histological type and tumor site) and residential proximity to industrial installations, according to categories of industrial groups and specific pollutants released, in the context of a population-based multicase-control study of incident cancer conducted in Spain (MCC-Spain).

METHODS

In this study, 2664 controls and 137 gastric cancer cases from 9 provinces, frequency matched by province of residence, age, and sex were included. Distances from the individuals' residences to the 106 industries located in the study areas were computed. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance (from 1 km to 3 km) to industries, adjusting for matching variables and potential confounders.

RESULTS

Overall, no excess risk of gastric cancer was observed in people living close to the industrial installations, with ORs ranging from 0.73 (at ≤2.5 km) to 0.93 (at ≤1.5 km). However, by industrial sector, excess risks (OR; 95%CI) were found near organic chemical industry (3.51; 1.42-8.69 at ≤2 km), inorganic chemical industry (3.33; 1.12-9.85 at ≤2 km), food/beverage sector (2.48; 1.12-5.50 at ≤2 km), and surface treatment using organic solvents (3.59; 1.40-9.22 at ≤3 km). By specific pollutant, a statistically significant excess risk (OR; 95%CI) was found near (≤3 km) industries releasing nonylphenol (6.43; 2.30-17.97) and antimony (4.82; 1.94-12.01).

CONCLUSIONS

The results suggest no association between risk of gastric cancer and living in the proximity to the industrial facilities as a whole. However, a few associations were detected near some industrial sectors and installations releasing specific pollutants.

Associations of BNIP3 and DAPK1 gene polymorphisms with disease susceptibility, clinicopathologic features, anxiety, and depression in gastric cancer patients

The purpose of this study is to explore the associations of BNIP3 and DAPK1 polymorphisms with disease susceptibility, clinicopathologic characteristics, depression, and anxiety in gastric cancer (GC) patients. In this study, 150 GC patients and 100 healthy controls were recruited. 1000 Genomes database and Haploview 4.0 software were used to select tag SNPs. Improved multiplex ligase detection reaction was used for genotyping. Data were analyzed using Chi-square test (χ² test) and univariate and multivariate logistic regression. The results demonstrated that the rs10781582 of BNIP3 in the dominant model was associated with a reduced risk of GC in the younger group (P _BH = 0.015), and the minor allele G of rs1329600 at DAPK1 was associated with reduced risk of GC (P _BH = 0.018). In the stratified analysis, the rs3793742 and rs10781582 of BNIP3 in the dominant model were associated with gender and age of GC patients, respectively (rs3793742: P _BH = 0.033; rs10781582: P _BH = 0.030). The rs10781582 of BNIP3 in the dominant model was correlated with depression in GC patients (P _BH = 0.003). However, no association was found between BNIP3 and DAPK1 polymorphisms and differentiation degree, TNM stage, lymph node metastases, visceral metastasis, and anxiety. In summary, polymorphisms of BNIP3 and DAPK1 were associated with a protective effect against GC. So far, this is the first study to explore the association between BNIP3 and DAPK1 gene polymorphism and GC risk, which may provide new insight about biologic mechanisms of GC pathogenesis.

A Quantitative Retrospective Exposure Assessment for Former Chrysotile Asbestos Miners and Millers from Baie Verte, NL, Canada

Despite numerous studies of asbestos workers in the epidemiologic literature, there are very few cohort studies of chrysotile asbestos miners/millers that include high-quality retrospective exposure assessments. As part of the creation of the Baie Verte Miners' Registry in 2008, a two-dimensional job exposure matrix (JEM) was developed for estimating asbestos exposures for former chrysotile asbestos miners/millers. Industrial hygiene data collected between 1963 and 1994 were analysed to assess validity for use in a retrospective exposure assessment and epidemiologic study. Registered former employees were divided into 52 exposure groups (EGs) based on job title and department and mean asbestos concentrations were calculated for each EG. The resulting exposure estimates were linked to individual registrants' work histories allowing for the calculation of cumulative asbestos exposure for each registrant. The distribution of exposure for most EGs (82.6%) could be described as fitting a log-normal distribution, although variability within some EGs (55%) exceeded a geometric standard deviation (GSD) of 2.5. Overall, the data used to create EGs in the development of the JEM were deemed to be of adequate quality for estimating cumulative asbestos exposures for the former employees of the Baie Verte asbestos mine/mill. The variability between workers in the same job was often high and is an important factor to be considered when using estimates of cumulative asbestos exposure to adjudicate compensation claims. The exposures experienced in this cohort were comparable to those of other chrysotile asbestos miners/millers cohorts, specifically Italian and Québec cohorts.

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.

Guidelines for endoscopic diagnosis of early gastric cancer

The Japan Gastroenterological Endoscopy Society developed the Guideline for Endoscopic Diagnosis of Early Gastric Cancer based on scientific methods. Endoscopy for the diagnosis of early gastric cancer has been acknowledged as a useful and highly precise examination, and its use has become increasingly more common in recent years. However, the level of evidence in this field is low, and it is often necessary to determine recommendations based on expert consensus only. This clinical practice guideline consists of the following sections to provide the current guideline: [I] Risk stratification of gastric cancer before endoscopic examination, [II] Detection of early gastric cancer, [III] Qualitative diagnosis of early gastric cancer, [IV] Diagnosis to choose the therapeutic strategy for gastric cancer, [V] Risk stratification after endoscopic examination, and [VI] Surveillance of early gastric cancer.

Colorectal cancer and asbestos exposure-an overview

The relationship between colorectal cancer and asbestos exposure has not been fully clarified. This study aimed to determine the associations between asbestos exposure and colorectal cancer. We performed a meta-analysis to quantitatively evaluate this association. A fixed effects model was used to summarize the relative risks across studies. Sources of heterogeneity were explored through subgroup analyses and meta-regression. We analyzed the dose-effect relationship using lung cancer standardized mortality ratio (SMR) and the risk of mesothelioma as a percent (%) as exposure surrogates. A total of 47 cohort studies were included. We identified 28 incidence cohort studies from 17 separate papers and extracted colorectal cancer standardized incidence ratio (SIR). Cancer mortality data were extracted from 19 separate cohorts among 13 papers. The overall colorectal cancer SMR for synthesis cohort was 1.07 (95% CI 1.02-1.12). Statistically significant excesses were observed in exposure to mixed asbestos (SMR/SIR=1.07), exposure to production (SMR/SIR=1.11), among asbestos cement workers (SMR/SIR=1.18) and asbestos textile workers (SMR/SIR=1.11). Additionally, we determined that the SMR for lung cancer increased with increased exposure to asbestos, as did the risk for colorectal cancer. This study confirms that colorectal cancer has a positive weak associations with asbestos exposure.

Gastric and rectal cancers in workers exposed to asbestos: a case series

BACKGROUND

The Occupational Safety and Health Research Institute (OSHRI) of the Korea had not recognized gastrointestinal cancer as work-related disease during their evaluation. However, in 2018 OSHRI recognized gastric and rectal cancers as work-related disease in asbestos-exposed workers. We present 2 such cases along supportive evidence of causation.

CASE PRESENTATION

Patient A: A 57-year-old man had worked for about 40 years since 1978 as an oxygen cutter at workplaces that dismantle ships, buildings, boilers, and thermal power plants. In November 2016, endoscopy and biopsy confirmed the diagnosis of advanced gastric cancer, for which he underwent subtotal gastrectomy and chemotherapy; however, he later died of the cancer. Patient B: A 71-year-old man had worked in shipbuilding and repair workplaces for approximately 49 years, being employed in pipe laying, asbestos insulation installation, grinding, and other ship repair work. In 2003, he was diagnosed of rectal cancer by abdominal computed tomography. He accordingly underwent surgical removal of the cancer. Based on the occupational history of the 2 patients and our review of the relevant literature addressing the occupational environment, we concluded that both patients had continuous exposure to high levels of asbestos while performing their jobs for 40 and 49 years, respectively.

CONCLUSION

Both patients had a history of smoking and drinking (non-occupational personal risk factors). However, the possibility of an increased risk of gastric and rectal cancers from asbestos exposure cannot be excluded. Therefore, we considered that occupational exposure to asbestos had contributed to the cancer diagnosis in these cases. Workers exposed to asbestos should be made aware of the possibility of gastric or rectal cancer, and should undergo monitoring and medical examinations. Appropriate compensation for gastric and rectal cancers that occur in workers exposed to asbestos are anticipated in future.

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.

Epidemiology of gastric cancer: global trends, risk factors and prevention

Gastric cancer remains one of the most common and deadly cancers worldwide, especially among older males. Based on GLOBOCAN 2018 data, stomach cancer is the 5^th most common neoplasm and the 3^rd most deadly cancer, with an estimated 783,000 deaths in 2018. Gastric cancer incidence and mortality are highly variable by region and highly dependent on diet and Helicobacter pylori infection. While strides in preventing and treating H. pylori infection have decreased the overall incidence of gastric cancer, they have also contributed to an increase in the incidence of cardia gastric cancer, a rare subtype of the neoplasm that has grown 7-fold in the past decades. A better understanding of the etiology and risk factors of the disease can help reach a consensus in approaching H. pylori infection. Dietary modification, smoking cessation, and exercise hold promise in preventing gastric cancer, while genetic testing is enabling earlier diagnosis and thus greater survival.

Cancer incidence and all-cause mortality among civilian men and women employed by the Royal Norwegian Navy between 1950 and 2005

OBJECTIVE

We aimed to investigate cancer incidence and all-cause mortality in a cohort of 8358 civilians (5134 men and 3224 women) employed by the Royal Norwegian Navy at any time between 1950 and 2005.

METHODS

The cohort was followed for cancer incidence and all-cause mortality from 1960 through 2015. Standardised incidence ratios (SIR) and mortality ratios (SMR) were calculated from national rates. Separate SIRs were calculated for a subgroup of male workshop workers and another of female cleaners.

RESULTS

Overall cancer incidence among men was similar to the reference rate; male breast cancer was more frequent (SIR = 3.23). Male workshop workers showed a SIR of 1.77 for stomach cancer, while their incidence of lympho-haematopoietic cancers was half that of the reference rates. Women had increased risks of overall cancer (SIR = 1.11), lung cancer (SIR = 1.35), and ovarian cancer (SIR = 1.39). Female cleaners showed a SIR of 2.33 for bladder cancer and a lowered incidence of brain cancer (SIR = 0.18). In the overall cohort, all-cause mortality was lower than expected for men (SMR = 0.92) and closer to the reference rate for women (SMR = 0.95).

CONCLUSION

In men, we observed a lowered all-cause mortality and an excess of stomach cancer in workshop workers. In women, increased risks of overall cancer, lung cancer and ovarian cancer was seen. An increased risk of bladder cancer and a lowered incidence of brain cancer was observed among female cleaners.

Talc exposure and risk of stomach cancer: Systematic review and meta-analysis of occupational cohort studies

BACKGROUND/PURPOSE

Talc powder is widely used in various industries, but the carcinogenic effects associated with talc are not well understood. The objective of this study was to estimate the risk of stomach cancer after occupational talc exposure.

METHODS

We conducted a meta-analysis was performed to calculate the meta-relative risk (mRR) of stomach cancer. We searched the MEDLINE, EMBASE, CNKI and Wanfang Data databases for publications prior to January 1, 2017 using talc, cancer, and mortality as the search terms. Only cohort studies with occupational talc exposure and stomach cancer statistics were included.

RESULTS

All pooled analyses were based on random-effects models. We selected 13 observational studies (12 publications) for the meta-analysis, and heterogeneity was observed among studies. Workers exposed to all forms of talc had a significantly increased mRR of 1.21 (95% CI: 1.03-1.42, p = 0.02) for stomach cancer. Workers exposed to talc not containing asbestiform fibers also had an increased mRR of 1.26 (95% CI: 0.97-1.63, p = 0.09).

CONCLUSION

The available data showed a positive association between occupational talc exposure and risk of stomach cancer. The association between talc not containing asbestiform fibers and risk of stomach cancer was not significant. Further epidemiological studies are required to evaluate the safety of talc.

Cancer incidence in a cohort of asbestos-exposed workers undergoing health surveillance

OBJECTIVES

To compare a local cohort of 2488 men occupationally exposed to asbestos and enrolled in a public health surveillance program with the 1995-2009 cancer incidence of the general population of Friuli Venezia Giulia (FVG) region, Northeast Italy, we conducted a historical cohort study.

METHODS

Standardized incidence ratios (SIRs), with 95% confidence interval (95% CI), for specific cancer sites were estimated in the cohort and in subgroups of workers employed in shipbuilding between 1974 and 1994. For internal comparisons, we calculated incidence rate ratios (IRRs) for all cancers, lung cancer and mesothelioma, by level of exposure to asbestos and sector of employment adjusted for smoking habits and age at start of follow-up.

RESULTS

Among cohort members the SIR was 8.82 (95% CI 5.95-12.61) for mesothelioma and 1.61 (95% CI 1.26-2.04) for lung cancer. In subgroup analyses, the SIR for lung cancer in subjects hired in shipbuilding between 1974 and 1984 was 2.09 (95% CI 1.32-3.13). In the overall cohort, a borderline increased incidence was also found for stomach cancer (SIR = 1.53 95% CI 0.96-2.31). Internal comparisons within the cohort show that among men with high asbestos exposure level the relative risk was almost threefold for lung cancer (IRR = 2.94 95% CI 1.01-8.57).

CONCLUSIONS

This cohort experienced an excess in the incidence of both mesothelioma and lung cancer, showing increasing incidence rates at higher level of asbestos exposure. For lung cancer, the relative incidence was highest among workers hired in shipbuilding between 1974 and 1984.

Framework for assessment and phytoremediation of asbestos-contaminated sites

We examine the feasibility of phytoremediation as an alternative strategy to limit the exposure of asbestos in site with asbestos-containing materials. We collected soils from four locations from two sites-one with naturally occurring asbestos, and another, a superfund site, where asbestos-containing materials were disposed over decades-and performed ecotoxicology tests. We also performed two experiments with crop cultivar and two grasses from serpentine ecotype and cultivar to determined best choice for phytoremediation. Asbestos concentrations in different size fractions of soils varied by orders of magnitude. However, different asbestos concentrations had little effect on germination and root growth. Presence of co-contaminants such as heavy metals and lack of nutrients affected plant growth to different extents, indicating that several of these limiting factors should be considered instead of the primary contaminant of concern. Crop cultivar survived on asbestos-contaminated soil. Grasses from serpentine ecotype did not show higher biomass than the cultivar. Overall, these results showed that soil conditions play a critical role in screening different crop species for phytoremediation and that asbestos concentration has limited to no effect on plant growth. Our study provided a framework for phytoremediation of asbestos-contaminated sites to limit long-term asbestos exposure.

Occupational Exposure to Talc Increases the Risk of Lung Cancer: A Meta-Analysis of Occupational Cohort Studies

OBJECTIVE

Talc is widely used in industrial applications. Previous meta-analyses of carcinogenic effects associated with inhaled talc included publications before 2004, with a lack of data in China, the largest talc-producing country. The safety of workers exposed to talc was unclear due to limited evidence. The objective of this study was to reevaluate the association between inhaled talc and lung cancer.

SETTING PARTICIPANTS AND OUTCOME MEASURES

A meta-analysis was performed to calculate the meta-SMR of lung cancer. We searched the MEDLINE, EMBASE, CNKI, and Wanfang Data databases through March 2017. Data from observational studies were pooled using meta-analysis with random effects models.

RESULTS

Fourteen observational cohort studies (13 publications) were located via literature search. The heterogeneity of the included data was high (I-squared = 72.9%). Pooling all the cohorts yielded a meta-SMR of 1.45 (95% CI: 1.22-1.72, p < 0.0001) for lung cancer among the study subjects exposed to talc. Subgroup analysis for asbestos contamination showed no significant difference in lung cancer death between subjects exposed to talc with and without asbestos (p = 0.8680), indicating that this confounding factor may have no significance.

CONCLUSIONS

This study provides evidence that nonasbestiform talc might still increase the risk of lung cancer. Further epidemiological studies are required to evaluate the safety of workers with occupational talc exposure.

Gastric cancer: somatic genetics as a guide to therapy

Gastric cancer is the leading cause of cancer-related mortality across the world, with poor prognosis and a median overall survival of ≤12 months for advanced stage gastric cancer. Environmental, genetic and other predisposing factors contribute to the development of gastric cancer and a predominant factor was found to be infection of Helicobacter pylori Advances in understanding the deranged signalling pathways that are critical for normal cellular homeostasis helped in the development of novel drugs that target specific proteins and pathways to curtail the growth of gastric cancer. Genetic studies revealed several single nucleotide polymorphisms, chromosomal aberrations and epigenetic alterations that likely play a major role in elevating the susceptibility to develop gastric cancer. Methylation pattern of specific genes may likely prove to be a valid biomarker for early detection of gastric cancer, but much progress is needed to establish specific markers. Important developments have been made in targeting human epidermal growth factor receptor-2 and vascular endothelial growth factor receptor 2 for treating advanced gastro-oesophageal junction cancer, using specific monoclonal antibodies. Lack of efficacy with regard to targeting other signalling pathways including mesenchymal-epithelial transition/hepatocyte growth factor and mammalian target of rapamycin is probably due to suboptimal patient selection for these clinical trials, which is probably due to the lack of appropriate biomarkers, to decide on responsive patient population. Besides the development of antagonists for the cell growth-related signalling pathways, advances are also being made to tackle gastric cancer by immunotherapies, targeting immune check-points, which may hold promise for better treatment options in future.

Post-9/11 cancer incidence in World Trade Center-exposed New York City firefighters as compared to a pooled cohort of firefighters from San Francisco, Chicago and Philadelphia (9/11/2001-2009)

BACKGROUND

We previously reported a modest excess of cancer in World Trade Center (WTC)-exposed firefighters versus the general population. This study aimed to separate the potential carcinogenic effects of firefighting and WTC exposure by comparing to a cohort of non-WTC-exposed firefighters.

METHODS

Relative rates (RRs) for all cancers combined and individual cancer subtypes from 9/11/2001 to 12/31/2009 were modeled using Poisson regression comparing 11,457 WTC-exposed firefighters to 8,220 urban non-WTC-exposed firefighters.

RESULTS

Compared with non-WTC-exposed firefighters, there was no difference in the RR of all cancers combined for WTC-exposed firefighters (RR = 0.96, 95%CI: 0.83-1.12). Thyroid cancer was significantly elevated (RR = 3.82, 95%CI: 1.07-20.81) from 2001 to 2009; this was attenuated (RR = 3.43, 95%CI: 0.94-18.94) and non-significant when controlling for possible surveillance bias. Prostate cancer was elevated during the latter half (2005-2009; RR = 1.38, 95%CI: 1.01-1.88).

CONCLUSIONS

Further follow-up is needed to assess the relationship between WTC exposure and cancers with longer latency periods. Am. J. Ind. Med. 59:722-730, 2016. © 2016 Wiley Periodicals, Inc.

Asbestos Fiber Preparation Methods Affect Fiber Toxicity

To measure the toxic potential of asbestos fibers-a known cause of asbestosis, lung cancer, and malignant mesothelioma-asbestos minerals are generally first ground down to small fibers, but it is unknown whether the grinding condition itself changes the fiber toxicity. To evaluate this, we ground chrysotile ore with or without water for 5-30 min and quantified asbestos-induced reactive oxygen species generation in elicited murine peritoneal macrophages as an indicator of fiber toxicity. The toxicity of dry-ground fibers was higher than the toxicity of wet-ground fibers. Grinding with or without water did not materially alter the mineralogical properties. However, dry-ground fibers contained at least 7 times more iron than wet-ground fibers. These results indicate that grinding methods significantly affect the surface concentration of iron, resulting in changes in fiber-induced reactive oxygen species generation or toxicity. Therefore, fiber preparation conditions should be accounted for when comparing the toxicity of asbestos fibers between reported studies.

Five years update on relationships between malignant pleural mesothelioma and exposure to asbestos and other elongated mineral particles

Despite the reduction of global asbestos consumption and production due to the ban or restriction of asbestos uses in more than 50 countries since the 1970s, malignant mesothelioma remains a disease of concern. Asbestos is still used, imported, and exported in several countries, and the number of mesothelioma deaths may be expected to increase in the next decades in these countries. Asbestos exposure is the main risk factor for malignant pleural mesothelioma, but other types of exposures are linked to the occurrence of this type of cancer. Although recent treatments improve the quality of life of patients with mesothelioma, malignant pleural mesothelioma remains an aggressive disease. Recent treatments have not resulted in appreciable improvement in survival, and thus development of more efficient therapies is urgently needed. The development of novel therapeutic strategies is dependent on our level of knowledge of the physiopathological and molecular changes that mesothelial cells acquired during the neoplastic process. During the past 5 years, new findings have been published on the etiology, epidemiology, molecular changes, and innovative treatments of malignant pleural mesothelioma. This review aims to update the findings of recent investigations on etiology, epidemiology, and molecular changes with a focus on (1) attributable risk of asbestos exposure in men and women and (2) coexposure to other minerals and other elongated mineral particles or high aspect ratio nanoparticles. Recent data obtained on genomic and gene alterations, pathways deregulations, and predisposing factors are summarized.

Asbestos exposure and laryngeal cancer mortality

OBJECTIVES/HYPOTHESIS

Occupational exposure to asbestos occurs in many workplaces and is well known to cause asbestosis, lung cancer, and mesothelioma. However, the link between asbestos exposure and other malignancies was not confirmed. The aim of the current meta-analysis was to provide a summary measure of risk for laryngeal cancer associated with occupational asbestos exposure.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Electronic databases were searched for studies characterizing the association between asbestos and laryngeal cancer. Standardized mortality rate (SMR) with its 95% confidence interval (CI) of each study was combined using a fixed or random effect model.

RESULTS

Significantly increased SMR for laryngeal cancer was observed when subjects were exposed to asbestos (SMR = 1.69, 95% CI = 1.45-1.97, P < .001), with little evidence of heterogeneity among studies (Q = 15.39, P = .803, I(2) = 0.0%). Effect estimates were larger for cohorts controlling for male subjects, Europe and Oceania, mining and textile industries, exposure to crocidolite, long study follow-up (>25 years), and SMR for lung cancer > 2.0. Publication bias was not detect by Begg test (P = .910) and Egger test (P = .340).

CONCLUSIONS

Our study supports the association of exposure to asbestos with an increased risk of laryngeal cancer mortality among male workers.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:1169-1174, 2016.