Hazardous air pollutants and primary liver cancer in Texas

Global, regional and national burden of liver cancer 1990-2021: a systematic analysis of the global burden of disease study 2021

BACKGROUND

Liver cancer is a growing global health issue, with significant geographical disparities in prevalence and mortality. Understanding these differences is key to developing effective prevention and treatment strategies.

METHODS

We analyzed liver cancer trends from 1990 to 2021 across 204 countries using data from the Global Burden of Disease (GBD) study. We modeled mortality from vital registration data and estimated non-fatal burden using primary studies, hospital discharges, and claims data. We calculated prevalence, mortality, YLLs, YLDs, and DALYs, adjusting for age and reporting rates per 100,000 population with 95% UI.

FINDINGS

In 2021, there were 739,299 (673114-821948) cases of liver cancer worldwide. The age-standardized prevalence rate increased from (7.75 [6.91-8.43] per 100,000 people) in 1990 to (8.68[7.90-9.67] per 100,000 people) in 2021, while the mortality rate slightly decreased from(4.48 [4.10-4.93] per 100,000 people) to (6.13 [5.58-6.84] per 100,000 people). High-income North America had the highest prevalence rate, and Southern Latin America had the lowest. Mongolia had the highest prevalence and mortality rates, while Morocco had the lowest. The total YLDs attributed to liver cancer nearly tripled from 1990 to 2021, and the age-standardized DALY rate decreased. In the frontier analysis, countries or regions with higher SDI have greater potential for burden improvement. In the frontier analysis of SDI and age-standardized liver cancer DALY rates in 2021, countries with higher SDI (> 0.85) and higher effective differences relative to their level of development include America, Canada, Germany, Netherlands, etc., while frontier countries with lower SDI (< 0.5) and lower effective differences include Somalia, Papua New Guinea, Yemen, Lao People's Democratic Republic, etc. Countries with larger effective differences include Togo, Gambia, Australia, Norway, etc. CONCLUSION: The global burden of liver cancer is decreasing, but the prevalence of liver cancer is increasing, with significant differences across regions worldwide. These findings can inform health policy and research to address this global challenge.

INTERPRETATION

From 1990 to 2021, the incidence of liver cancer in many regions has increased significantly, which is expected to impose a huge social and economic burden on governments and health systems in the coming years. Our research findings may assist policymakers in devising strategies to combat liver cancer, including educating professionals to address the burden of this complex disease.

Exploring the association between air pollution and the incidence of liver cancers

Liver cancer, namely hepatocellular carcinoma (HCC), is a major global health concern deeply influenced by environmental factors. Air pollutants emerged as significant contributors to its incidence. This review explores the association between air pollution-specifically particulate matter (PM2.5), industrial chemicals like vinyl chloride, and benzene-and the increased risk of liver cancer. Mechanistically, air pollutants may cause liver damage by inducing oxidative stress, inflammation, and genetic mutations, contributing to cancer development. Epidemiological evidence from cohort and geographic studies highlights a positive correlation between long-term exposure to air pollutants and elevated incidence and mortality of liver cancer. Furthermore, air pollution has been shown to worsen survival outcomes in liver cancer patients, particularly those diagnosed at early stages. The review emphasizes the need for stricter air quality regulations and relevant research for underlying mechanisms exposed to air pollution. Addressing air pollution exposure could be crucial for reducing liver cancer risks and improving public health outcomes.

Incidence and Geographical Distribution of Adrenocortical Carcinoma: Retrospective Analysis of a State Cancer Registry

OBJECTIVE

Adrenocortical carcinoma (ACC) is a rare malignancy without established association with environmental risk factors. ACC incidence is stable based on large surgical databases while referral centers data reported increasing number of cases seen. We studied ACC incidence and distribution at a county level to find potential ACC "hot spots" that could be linked to environmental exposures.

METHODS

A retrospective analysis of Texas Cancer Registry that included ACC patients diagnosed between 2000 and 2018. County-level heatmaps were created and compared with breast, prostate, and lung cancer.

RESULTS

We identified 448 ACC cases during the study period. Cases were registered in 110 of the 254 counties (43.3%) in Texas, representing 92.74% of the total population. The median incidence was 23 new cases/y (range 14-33). The mean population-adjusted ACC incidence rate was 0.104 per 100 000 per year (standard deviation 0.005; 95% CI, 0.092-0.116). Seven counties (6.3%) accounted for 215 (48.0%) cases, with more than 10 cases each and median standardized incidence ratio (SIR) of 0.1 (range, 0.0-0.9). One hundred three counties (93.7%) accounted for the remaining 233 cases (52%), with fewer than 10 cases per county. The highest standardized incidence ratios were found in counties with a median population of fewer than 14 000 residents and with only one reported case.

CONCLUSION

Our analysis is the first report to create ACC heatmap and could not detect any geographic clustering of ACC in Texas. The incidence of ACC remained stable and consistent with data from other large databases.

Association of air pollution with postmenopausal breast cancer risk in UK Biobank

BACKGROUND

We investigated the association of several air pollution measures with postmenopausal breast cancer (BCa) risk.

METHODS

This study included 155,235 postmenopausal women (of which 6146 with BCa) from UK Biobank. Cancer diagnoses were ascertained through the linkage to the UK National Health Service Central Registers. Annual exposure averages were available from 2005, 2006, 2007, and 2010 for NO2, from 2007 and 2010 for PM10, and from 2010 for PM2.5, NOX, PM2.5-10 and PM2.5 absorbance. Information on BCa risk factors was collected at baseline. Cox proportional hazards regression was used to evaluate the associations of year-specific and cumulative average exposures with BCa risk, overall and with 2-year exposure lag, while adjusting for BCa risk factors.

RESULTS

PM10 in 2007 and cumulative average PM10 were positively associated with BCa risk (2007 PM10: Hazard ratio [HR] per 10 µg/m3 = 1.18, 95% CI 1.08, 1.29; cumulative average PM10: HR per 10 µg/m3 = 1.99, 95% CI 1.75, 2.27). Compared to women with low exposure, women with higher 2007 PM10 and cumulative average PM10 had greater BCa risk (4th vs. 1st quartile HR = 1.15, 95% CI 1.07, 1.24, p-trend = 0.001 and HR = 1.35, 95% CI 1.25, 1.44, p-trend < 0.0001, respectively). No significant associations were found for any other exposure measures. In the analysis with 2-year exposure lag, both 2007 PM 10 and cumulative average PM10 were positively associated with BCa risk (4th vs. 1st quartile HR = 1.19, 95% CI 1.10, 1.28 and HR = 1.29, 95% CI 1.19, 1.39, respectively).

CONCLUSION

Our findings suggest a positive association of 2007 PM10 and cumulative average PM10 with postmenopausal BCa risk.

Increased Risk of Malignancy with Immunosuppression: A Population-Based Analysis of Texas Medicare Beneficiaries

Immunosuppressive drugs (IMD) are widely utilized to treat many autoimmune conditions and to prevent rejection in organ transplantation. Cancer has been associated with prolonged use of IMD in transplant patients. However, no detailed, systematic analysis of the risk of cancer has been performed in patients receiving IMD for any condition and duration. We analyzed Medicare data from Texas Medicare beneficiaries, regardless of their age, between 2007 and 2018, from the Texas Cancer Registry. We analyzed the data for the risk of cancer after IMD use associated with demographic characteristics, clinical conditions, and subsequent cancer type. Of 29,196 patients who used IMD for a variety of indications, 5684 developed cancer. The risk of cancer (standardized incidence ratio) was particularly high for liver (9.10), skin (7.95), lymphoma (4.89), and kidney (4.39). Patients receiving IMD had a four fold greater likelihood of developing cancer than the general population. This risk was higher within the first 3 years of IMD utilization and in patients younger than 65 years and minorities. This study shows that patients receiving IMD for any indications have a significantly increased risk of cancer, even with short-term use. Caution is needed for IMD use; in addition, an aggressive neoplastic diagnostic screening is warranted.

The association between air pollution and cancers: controversial evidence of a systematic review

There are inconsistent reports on the association between air pollution and cancers. This systematic review was, therefore, conducted to ascertain the relationship between air pollution and some cancers. This is a systematic review study, which all articles published in this area were extracted from January 1, 1950 to December 31, 2018 from Web of Science, PubMed, Scopus, Cochrane Library, MEDLINE, EMBASE, Science Direct, Google scholar. Searching was performed independently by two search-method experts. The required data were extracted from the articles by an author-made questionnaire. Forty-eight articles were investigated. Evidence linking air pollution to some cancers is limited. Leukemia had the highest association with exposure to various air pollutants and bladder cancer had the lowest association. It is noteworthy that the specific type of pollutants in all studies was not specified. Based on the findings, the results are contradictory, and the role of air pollution in some cancers cannot be supported. Accordingly, studies are recommended to be performed at the individual level or multifactorial studies to specifically investigate the relationship between air pollution and these types of cancers. In this way, the role of air pollution in the incidence of these cancers can be determined more accurately.

Separation of air components and pollutants by the Earth's gravitational field

In this work, we develop a model able to predict the equilibrium separation of gases due to differences in their molecular weights and the action of gravity. The separation of H, He, O, and N₂ with altitude is a characteristic phenomenon of the heterosphere. The model is able to qualitatively recreate the compositional profile of the whole heterosphere from a single composition measurement. The model is applied to the separation of air components and pollutants by empty wells drilled on the planet surface. It predicts that the separation of gases would be possible in wells deep enough under equilibrium. The high molecular weight of some anthropogenic pollutants (SO₂, O₃, NO₂, CO₂, etc.) would facilitate their segregation along shorter distances compared to those involved in the heterosphere. The simulations indicate that deep wells could concentrate some air components and pollutants by orders of magnitude over the levels at the Earth's surface without external energy input. For instance, argon molar fractions of >40% and >60% could be achievable at 44 km and 55 km depth, respectively. Finally, we discuss the feasibility of gravitational separation as a potential pollution abatement technology.

microRNA-16 Via Twist1 Inhibits EMT Induced by PM2.5 Exposure in Human Hepatocellular Carcinoma

Epidemiological study has confirmed that PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 μm) is associated with the incidence and progression of human hepatocellular carcinoma (HCC). Accordingly, this study was undertaken to investigate the pro-metastatic effects of PM2.5 on human HCC cell line SMMC-7721 in vitro and to explore the underlying mechanisms. CCK-8 assay was performed to examine the effect of PM2.5 on the proliferation of SMMC-7721 cells; scratch wound assay and transwell matrigel system has been used to examine the effect of PM2.5 on the migration and invasion ability of SMMC-7721 cells; furthermore, effect of PM2.5 on epithelial mesenchymal transition (EMT) of SMMC-7721 cells were examined by examining the EMT markers vimentin, ɑ-smooth muscle actin (ɑ-SMA), and E-cadherin; furthermore, the roles of microRNA-16 (miR-16) and its target Twist1 in PM2.5 induced carcinogenic effects were also examined. Results of CCK-8 assay suggested that PM2.5 promoted the proliferation of SMMC-7721 cells in a dose and time dependent manner. PM2.5 also markedly promoted the migration and invasion ability of SMMC-7721 cells. Moreover, epithelial mesenchymal transition (EMT) was also triggered by PM2.5. On the other hand, microRNA-16 (miR-16) and its target Twist1 was found to be mediated by PM2.5, and miR-16 mimic could suppress the metastatic ability of SMMC-7721 cells exposure to PM2.5 via inversely regulating the expression of Twist1. Furthermore, dual Luciferase reporter assay confirmed the specifically binding of miR-16 to the predicted 3′-UTR of Twist1. The present study confirmed the pro-proliferative and pro-metastatic effect of PM2.5 on HCC cell line SMMC-7721. The possible mechanisms were EMT process induced by PM2.5 in SMMC-7721 cells, which was accompanied by a decrease in miR-16 and increase in Twist1 expression.

Hazardous air pollutants and telomere length in the Sister Study

BACKGROUND

Telomeres are vital for genomic integrity and telomere length has been linked to many adverse health outcomes. Some hazardous air pollutants, or air toxics, increase oxidative stress and inflammation, two possible determinants of shortened telomere length. No studies have examined air toxic-telomere length associations in a non-occupational setting.

METHODS

This study included 731 Sister Study participants (enrolled 2003-2007) who were randomly selected to assess telomere length in baseline blood samples. Multiplex qPCR was used to determine telomere to single copy gene (T/S) ratios. Census tract concentration estimates of 29 air toxics from the 2005 National Air Toxics Assessment were linked to baseline residential addresses. Air toxics were classified into tertile-based categories of the exposure. Multivariable linear regression was used to estimate β coefficients and 95% confidence intervals (CI) in single pollutant models. Multipollutant groups were identified with regression trees.

RESULTS

The average T/S ratio was 1.24. Benzidine (T3vsT1 β= -0.08; 95% CI: -0.14, -0.01) and 1,4-dioxane (T3vsT1 β= -0.06; 95% CI: -0.13, 0.00) in particular, as well as carbon tetrachloride, chloroprene, ethylene dibromide, and propylene dichloride, were associated with shorter relative telomere length. Benzidine (p=0.02) and 1,4-dioxane (p=0.06) demonstrated some evidence of a monotonic trend. The regression tree identified age, BMI, physical activity, ethylene oxide, acrylonitrile, ethylidene dichloride, propylene dichloride, and styrene in multipollutant groups related to telomere length.

CONCLUSIONS

In this first study of air toxics and telomere length in a non-occupational setting, several air toxics, particularly 1,4-dioxane and benzidine, were associated with shorter relative telomere length.