Histological types of lung cancer attributable to fine particulate, smoking, and genetic susceptibility

Long-term exposure to air pollution and lung cancer incidence: findings from improved exposure assessment and extended population

PURPOSE

Accumulating evidence suggested long-term exposure to air pollution as a risk factor of lung cancer. Recent efforts confirmed the association based on extended population and individual exposure by leveraging administrative databases and complete address information. However, few studies achieved simultaneous improvements. Using the 2 million cohort along with their individual residential exposures, this study aimed to investigate the association of four criteria pollutants and incident lung cancer in the Seoul Metropolitan Area, South Korea.

METHODS

Our study population included 2,035,278 people aged ≥ 30 years and without cancer for 2002-2006 from the National Health Insurance System database. We identified lung cancer incidence for 2007-2016 and assessed individual long-term exposure to particulate matter ≤ 10 µm and 2.5 µm in diameter (PM10 and PM2.5), nitrogen dioxide (NO2), and ozone at participants' home addresses by using previously validated exposure prediction models. Using time-varying Cox proportional hazard models, we estimated hazard ratios (HRs) per interquartile range increase in each pollutant concentration adjusting for individual and area-level characteristics.

RESULTS

There were 18,229 lung cancer new cases over 10 years. We did not find the association for all four pollutants (PM10: HR = 0.99 [95% Confidence Interval = 0.93-1.04]; PM2.5: 0.97 [0.92-1.02]; NO2: 1.00 [0.96-1.05]; and ozone: 1.01 [0.98-1.04]). The extended stratified and sensitivity analyses mostly showed null associations.

CONCLUSION

Our findings of no association contradictory to existing evidence, despite the considerable improvement in exposure assessment and population size, suggest further examination by integrating histological variation and indoor and/or personal exposure.

Fine particulate matter exposure and cancer risk: a systematic review and meta-analysis of prospective cohort studies

Studies examining the relationship between fine particulate matter (PM2.5) exposure and cancer risk is inconclusive, with an evident scarcity of comprehensive data on the overall cancer risk. Given the emergence of new evidence, updated meta-analyses is essential. A search was performed on multiple databases including PubMed, Embase, Scopus, Web of Science, and the Cochrane Library up to Jan 2025. Hazard ratios (HRs), relative risks (RRs), or incidence rate ratios (IRRs) with their 95 % confidence intervals (CIs) were extracted and pooled. Moreover, a comprehensive and detailed quality assessment of the included studies was conducted to validate the plausibility of the findings. Overall, 57 original studies were included, covering 36 cancer categories and including overall cancer and malignancies specific to particular anatomical sites. For each increase of 10 μg per cubic meter in PM2.5 concentration, there was an observed pooled HR of 1.07 for overall cancer (95 %CI:1.02-1.13). In the case of site-specific cancers, the pooled HRs were 1.11 (95 %CI:1.07-1.15), 1.06 (95 %CI:1.02-1.11), 1.17 (95 %CI:1.07-1.28), and 1.14 (95 %CI:1.03-1.26) for lung, breast, liver and esophageal cancers, respectively. Furthermore, PM2.5 exposure may potentially correlate with the risk of cancers at other anatomical locations including upper aerodigestive tract, oral cavity, kidney, skin, as well as digestive organs. In light of available evidence, it is inferred that PM2.5 exposure could potentially raise overall cancer risk with moderate certainty. As for site-specific malignancies, there is very low certainty evidence for lung cancer, low certainty evidence for breast cancer, and moderate certainty evidence for both liver and esophageal cancers.

Hypothetical Behavioral Interventions for Mitigating the Cardiovascular Effects of Long-Term Fine Particulate Matter Exposure: Analyses From 2 Prospective Cohorts

BACKGROUND

Whether healthy behaviors can attenuate the adverse association between ambient fine particulate matter (PM2.5) and cardiovascular disease (CVD) is inconclusive.

METHODS AND RESULTS

The parametric g-formula was used to quantify the potential reduction in PM2.5 effect on CVD under different scenarios of hypothetical behavioral interventions (including dietary patterns, physical activity, body mass index, alcohol consumption, smoking, and dietary supplements). Feasible intervention scenarios, defined on the basis of values considered feasible in previous real-world interventions (eg, overweight participants lose 6.69% of their weight). Intensive scenarios, in which all participants are adopting completely healthy behaviors (eg, maintain normal weight). We also estimate the effect of joint interventions that incorporate the above behaviors. Long-term PM2.5 exposure was associated with incident CVD in both cohorts, with the risk difference per 1000 person-years for a 5 μg/m3 increase in PM2.5 being 1.42 (95% CI, 1.04-1.79) in the UKB (UK Biobank) and 2.15 (95% CI, 1.65-2.59) in the Sichuan Cohort (China Multi-Ethnic Cohort, Sichuan Region). In both feasible and intensive scenarios, improving diet, physical activity, and body mass index could significantly reduce the risk difference of PM2.5 on CVD, with the reduced proportion ranging from 4.59% to 37.22%. A feasible joint hypothetical intervention on 6 behaviors would reduce the effect of PM2.5 on CVD by 31.47% (10.13%-57.26%) and 19.75% (10.78%-42.89%) in the low-pollution UK Biobank and high-pollution Sichuan cohort, respectively. A combination of more intensive interventions would reduce risk difference by 57.51% (21.64%-100.69%) and 45.54% (22.66%-106.66%), respectively.

CONCLUSIONS

Healthier behaviors could serve as individual-level complementary strategies to emission control for minimizing the health impact of PM2.5, whether in high- or low-pollution areas.

Basement membranes in lung metastasis growth and progression

The lung is a highly vascularized tissue that often harbors metastases from various extrathoracic malignancies. Lung parenchyma consists of a complex network of alveolar epithelial cells and microvessels, structured within an architecture defined by basement membranes. Consequently, understanding the role of the extracellular matrix (ECM) in the growth of lung metastases is essential to uncover the biology of this pathology and developing targeted therapies. These basement membranes play a critical role in the progression of lung metastases, influencing multiple stages of the metastatic cascade, from the acquisition of an aggressive phenotype to intravasation, extravasation and colonization of secondary sites. This review examines the biological composition of basement membranes, focusing on their core components-collagens, fibronectin, and laminin-and their specific roles in cancer progression. Additionally, we discuss the function of integrins as primary mediators of cell adhesion and signaling between tumor cells, basement membranes and the extracellular matrix, as well as their implications for metastatic growth in the lung. We also explore vascular co-option (VCO) as a form of tumor growth resistance linked to basement membranes and tumor vasculature. Finally, the review covers current clinical therapies targeting tumor adhesion, extracellular matrix remodeling, and vascular development, aiming to improve the precision and effectiveness of treatments against lung metastases.

Noise Exposure in the Workplace, Genetic Susceptibility, and Incidence of Atrial Fibrillation: A Prospective Cohort Study

BACKGROUND

No study explored the association of noise exposure in the workplace and genetic susceptibility with incidence of atrial fibrillation (AF). We aimed to assess the separate and joint relationship of noise exposure in the workplace and genetic susceptibility with the risk of AF.

METHODS AND RESULTS

We included 167 577 participants without AF at baseline in UK Biobank. Cox proportional hazards models were used to assess the separate and joint association of noise exposure in the workplace and genetic susceptibility with the risk of AF. During a median follow-up of 11.83 years, we observed 9355 AF cases. Compared with no noise exposure in the workplace, the hazard ratios (HRs) and were 1.08 (95% CI, 0.99-1.18) for noise exposure in the workplace of <1 year, 1.03 (95% CI, 0.95-1.12) for noise exposure in the workplace of around 1 to 5 years, and 1.08 (95% CI, 1.02-1.14) for noise exposure in the workplace of >5 years, respectively, after adjusting for potential confounders. Genetic risk was positively associated with AF, compared with low genetic risk (tertile 1), the HRs were 1.50 (95% CI, 1.41-1.59) for medium genetic risk (tertile 2) and 2.51 (95% CI, 2.38-2.65) for high genetic risk (tertile 3). However, no interaction between noise exposure in the workplace and genetic susceptibility was observed (P>0.05).

CONCLUSIONS

Long-term noise exposure in the workplace is positively associated with a higher incidence of AF regardless of genetic background.

Insulin-like growth factor 1 receptor expression correlates with programmed death ligand 1 expression and poor survival in non-small cell lung cancer

The insulin-like growth factor 1 receptor (IGF1R) has been associated with growth and metastasis in various cancers. However, its role in postoperative recurrence and prognosis in lung cancer lacks clear consensus. Therefore, this study aimed to investigate the potential relationship between IGF1R and postoperative recurrence as well as long-term survival in a large cohort. Additionally, we assessed the relationship between IGF1R and programmed death ligand 1 (PD-L1) expression. Our study encompassed 782 patients with non-small cell lung cancer (NSCLC). Immunostaining of surgical specimens was performed to evaluate IGF1R and PD-L1 expression. Among the patients, 279 (35.8%) showed positive IGF1R expression, with significantly worse relapse-free survival (RFS) and overall survival (OS). Notably, no significant differences in RFS and OS were observed between IGF1R-positive and -negative groups in stages 2 and 3. However, in the early stages (0-1), the positive group displayed significantly worse RFS and OS. In addition, PD-L1 expression was detected in 100 (12.8%) patients, with a significant predominance in the IGF1R-positive. IGF1R may serve as a prognostic indicator and a guide for perioperative treatment strategies in early-stage lung cancer. In conclusion, our findings underscore an association between IGF1R expression and poor survival and PD-L1 expression in NSCLC.

Causal role of immune cells in lung cancer subtypes: Mendelian randomization study

Lung cancer, characterized by its high incidence and mortality rates, is a challenging malignancy to treat. Immunotherapy has emerged as a crucial treatment modality, yet its effectiveness varies significantly among patients due to the diverse immune microenvironment involved. Our study aims to analyze the similarities and differences in immune cell profiles across different subtypes of lung cancer. We employed a comprehensive two-sample Mendelian randomization analysis to establish causal connections between immune cells and lung cancer. We examined differential expression of 731 immune cell types and compared their profiles among various lung cancer subtypes. Our analysis revealed that 47 immune cell types exhibited differential expression in lung cancer, with 15 showing a protective effect and 32 having a tumor-promoting effect. Notably, we observed greater similarities in immune cell profile between squamous carcinoma and adenocarcinoma subtypes, while small cell lung cancerHHHH displayed less overlap with the other two types. Specifically, CD4+ naive T cells showed differential expression across all three lung cancer subtypes, whereas three other immune cell types exhibited differential expression exclusively in adenocarcinoma and squamous cell carcinoma. Our findings substantiate a causal link between immune cell dynamics and lung cancer progression. Moreover, our identification of distinct immune cell composition among histological subtypes of lung cancer may serve as a valuable reference for further investigation into immunotherapeutic strategies.

Targeting microRNAs as a promising anti-cancer therapeutic strategy against traffic-related air pollution-mediated lung cancer

Air pollutants are increasingly emitted into the atmosphere because of the high dependency of humans on fossil-derived fuels. Wind speed and direction assisted high dispersibility and uncontrolled nature of air pollution across geo-/demographical borders, making it one of the major global concerns. Besides climate change, air pollution has been found to be associated with various diseases, such as cancer. Lung cancer, which is the world's most common type of cancer, has been found to be associated with traffic-related air pollution. Research and political efforts have been taken to explore green/renewable energy sources. However, these efforts at the current intensity cannot cope with the increasing need for fossil fuels. More specifically, political tensions such as the Russian-Ukraine war, economic tension (e.g., China-USA economic tensions), and other issues (e.g., pandemic, higher inflation rate, and poverty) significantly hindered phasing out fossil fuels. In this context, an increasing global population will be exposed to traffic-related air pollution, which justifies the current uptrend in the number of lung cancer patients. To combat this health burden, novel treatments with higher efficiency and specificity must be designed. One of the potential "life changer" options is microRNA (miRNA)-based therapy to target the expression of oncogenic genes. That said, this review discusses the association of traffic-related air pollution with lung cancer, the changes in indigenous miRNAs in the body during lung cancer, and the current status of miRNA therapeutics for lung cancer treatment. We believe that the article will significantly appeal to a broad readership of oncologists, environmentalists, and those who work in the field of (bio)energy. It may also gain the policymakers' attention to establish better health policies and regulations about air pollution, for example, by promoting (bio)fuel exploration, production, and consumption.

Identification of the novel biomarkers involved in the mitochondrial metabolism-related reactive oxygen species and their role in lung cancer T-cell exhaustion and immunotherapy

Purpose

To study the role of mitochondrial metabolism and obtain novel biomarkers in immunotherapy for non-small cell lung cancer (NSCLC).

Methods

We collected the 188 genes involved in mitochondrial metabolism(MMGs) from the MSIGDB project and then quantified the activity of mitochondrial metabolism. All the NSCLC patients were divided into C1 and C2 clusters based on the 26 prognosis-related MMGs. The differences in biology, differential immune microenvironment, chronic hypoxia and prognosis between C1 and C2 patients were also analyzed. In addition, we validated the results of bioinformatics analysis in lung cancer tissues and cell lines.

Results

Patients in the C2 cluster had a higher level of mitochondrial metabolism. Patients in the C2 cluster responded better to immunotherapy and had a lower level of T-cell exclusion. The markers of T-cell failure were upregulated in the C1 patients. Hypoxia can lead to a high percentage of C1 patients. ADH1C might be involved in mitochondrial metabolism and immunotherapy response, which can be affected by hypoxia, making it an underlying biomarker. The expression levels of ADH1C in BEAS-2B, H1299, A549 and H460 cells were detected, revealing that ADH1C is upregulated in lung cancer cells. We observed that patients with low ADH1C expression had a longer survival time. The enzyme activities of HK, PK, LDH and SDH were significantly reduced in H1299 and H460 cells with ADH1C knockdown, along with more ROS. Furthermore, the expression levels of PD-L1 and HHLA2 in tumor tissues were analyzed, which found that ADH1C was significantly positively correlated with the expression of PD-L1 and HHLA2.

Conclusions

In summary, our study comprehensively explored the molecules involved in mitochondrial metabolism and their role in immunotherapy and T lymphocyte failure.

Exploration of the prognostic prediction value of the PANoptosis-based risk score and its correlation with tumor immunity in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a common cancer with high mortality worldwide. PANoptosis is a novel inflammatory programmed cell death modality with the characteristics of pyroptosis, apoptosis and necroptosis. It is necessary to explore PANoptosis-related genes in LUAD patients and offer evidence for prognosis prediction and therapeutic strategies. Single-cell RNA sequencing data and RNA expression profiles of LUAD patients from The Cancer Genome Atlas and Gene Expression Omnibus databases are used to screen PANoptosis-related differential genes for the construction of a risk model. Fifteen PANoptosis-related markers with prognostic value were identified by Least Absolute Shrinkage and Selection Operator (LASSO)-Cox regression analysis. Kaplan-Meier analysis and receiver operating characteristic curve analysis further demonstrated the significant predictive capability. Immune infiltration, Single Nucleotide Variants (SNV) mutations, and clinical drug susceptibility were analyzed. In conclusion, a risk model of 15 PANoptosis-related genes has significant value in prognostic prediction for LUAD and has potential to direct clinical therapeutic strategies during the treatment.

Short-Term Ambient Air Pollution and Urticaria in Guangzhou, China: Estimating the Association and Population Attributable Fraction

Limited evidence is available regarding the association between acute exposure to ambient air pollutants and the risk of urticaria, even though the skin is an organ with direct contact with the external environment. This study utilized generalized additive models to investigate the association between particulate matter with an aerodynamic diameter smaller than 10 μm (PM10) and 2.5 μm (PM2.5), nitrogen dioxide (NO2) and sulfur dioxide (SO2), and daily outpatient visits for urticaria in Guangzhou, China from 2013 to 2017. We also estimated the attributable fraction of urticaria outpatient visits due to air pollution. A total of 216,648 outpatient visits due to urticaria occurred during the study period. All air pollutants were significantly associated with an increased excess risk of urticaria. Each 10 μg/m3 increase in PM2.5, PM10, NO2, and SO2 was associated with an increase of 1.23% (95% CI: 0.42%, 2.06%), 0.88% (95% CI: 0.28%, 1.49%), 3.09% (95% CI: 2.16%, 4.03%), and 2.82% (95% CI: 0.93%, 4.74%) in hospital visits for urticaria at lag05, respectively. It was estimated that 3.77% (95% CI: 1.26%, 6.38%), 1.91% (95% CI: 0.60%, 3.26%), 6.36% (95% CI: 4.38%, 8.41%), and 0.08% (95% CI: 0.03%, 0.14%) of urticaria outpatient visits were attributable to PM2.5, PM10, NO2, and SO2 using the World Health Organization's air quality guideline as the reference. Relatively stronger associations were observed during the cold season. This study indicates that short-term air pollution may play a significant role in outpatient visits for urticaria, and that such relationships could be modified by season.

Association of telomere length with risk of lung cancer: A large prospective cohort study from the UK Biobank

OBJECTIVES

Leukocyte telomere length (LTL) is associated with a wide variety of diseases, including cancer. However, findings regarding the association between LTL and the risk for lung cancer have been inconclusive and inconsistent across previous observational studies.

METHODS

This prospective cohort study included data from 425,146 participants 37-73 years of age housed in the UK Biobank. Quantitative polymerase chain reaction (qPCR) was used to measure LTL in baseline DNA samples. A multivariate Cox proportional hazards model was used to evaluate the relationship between LTL and the risk for lung cancer.

RESULTS

An increase in LTL per interquartile range (IQR) was associated with a 9% increase in the risk for lung cancer (hazard ratio [HR] 1.09 [95% confidence interval (CI) 1.03-1.16]). Participants in the highest LTL quintile exhibited an approximately 25% elevated risk for developing lung cancer (HR 1.25 [95% CI 1.09-1.45]) compared with those in the lowest quintile. The relationship between per IQR increase in LTL and elevated risk for lung cancer was greater in the histological subtype of adenocarcinoma (HR 1.30 [95% CI 1.18-1.43]), female sex (HR 1.16 [95% CI 1.06-1.26]), non-smokers (HR 1.45 [95% CI 1.23-1.71]), and individuals with high genetic risk for lung cancer (HR 1.18 [95% CI 1.03-1.34]), respectively. Surprisingly, a per IQR increase in LTL was associated with increased risks for both lung adenocarcinoma (HR 1.56 [95% CI 1.24-1.96]) and squamous cell carcinoma (HR 2.01 [95% CI 1.13-3.56]) in never smokers.

CONCLUSIONS

Longer LTL was associated with an elevated risk for lung cancer, particularly for adenocarcinoma and squamous cell carcinoma in never smokers. The results suggest the potential of telomeres as non-invasive biomarkers for the early screening of lung cancer, particularly in non-smokers, who are typically overlooked.

Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk

Lung cancer (LC) is the second-most prevalent tumor worldwide. According to the most recent GLOBOCAN data, over 2.2 million LC cases were reported in 2020, with an estimated new death incident of 1,796,144 lung cancer cases. Genetic, lifestyle, and environmental exposure play an important role as risk factors for LC. E-cigarette, or vaping, products (EVPs) use has been dramatically increasing world-wide. There is growing concern that EVPs consumption may increase the risk of LC because EVPs contain several proven carcinogenic compounds. However, the relationship between EVPs and LC is not well established. E-cigarette contains nicotine derivatives (e.g., nitrosnornicotine, nitrosamine ketone), heavy metals (including organometal compounds), polycyclic aromatic hydrocarbons, and flavorings (aldehydes and complex organics). Several environmental toxicants have been proven to contribute to LC. Proven and plausible environmental carcinogens could be physical (ionizing and non-ionizing radiation), chemicals (such as asbestos, formaldehyde, and dioxins), and heavy metals (such as cobalt, arsenic, cadmium, chromium, and nickel). Air pollution, especially particulate matter (PM) emitted from vehicles and industrial exhausts, is linked with LC. Although extensive environmental exposure prevention policies and smoking reduction strategies have been adopted globally, the dangers remain. Combined, both EVPs and toxic environmental exposures may demonstrate significant synergistic oncogenicity. This review aims to analyze the current publications on the importance of the relationship between EVPs consumption and environmental toxicants in the pathogenesis of LC.