Long-term exposure to several constituents and sources of PM2.5 is associated with incidence of upper aerodigestive tract cancers but not gastric cancer: Results from the large pooled European cohort of the ELAPSE project

Associations between long-term exposure to fine particulate matter and its constituents with lung cancer incidence: Evidence from a prospective cohort study in Beijing, China

Association between long-term exposure to ambient fine particulate matter (PM2.5) and lung cancer incidence is well-documented. However, the role of different PM2.5 constituents [black carbon (BC), ammonium (NH4+), nitrate (NO3-), organic matter (OM), and inorganic sulfate (SO42-)] remain unclear. The study aimed to specify the associations between PM2.5 constituents and lung cancer incidence. Based on a prospective cohort of 130,860 participants in Beijing, the present study utilized Cox model to explore the associations between PM2.5 constituents and lung cancer incidence. We further used mixed exposure models [weighted quantile sum (WQS) and quantile-based g-computation (Qgcomp)] and machine learning model [random forest model with SHapley Additive exPlanations (SHAP)] to specify the importance of each constituent. Results indicated that PM2.5 mass and its constituents were significantly associated with increased lung cancer incidence. The hazard ratios (HRs) and 95% confidence intervals (CIs) of 1-μg/m3 increase in the 5-year average concentrations were 1.01 (95% CI: 1.00, 1.02) for PM2.5 mass, 1.23 (95% CI: 1.06, 1.42) for BC, 1.15 (95% CI: 1.04, 1.27) for NH4+, 1.08 (95% CI: 1.02, 1.16) for NO3-, 1.04 (95% CI: 1.01, 1.06) for OM, and 1.08 (95% CI: 1.03, 1.15) for SO42-. Both the WQS and Qgcomp models assigned the two highest positive weights to BC and SO42-. SHAP analysis identified SO42- and BC as the first and third most important contributors, respectively. Our results indicated that PM2.5 mass and its constituents were significantly associated with lung cancer incidence, and BC and SO42- were the key constituents in these associations.

Does ambient particulate matter 1 increase the risk of gastric cancer in the northwest of China?

Gastric cancer (GC) remains a significant health concern in Gansu province, China, with morbidity and mortality rates surpassing national averages. Despite the recognized health risks associated with ambient particulate matter with an aerodynamic diameter <1 μm (PM1), the relationship between PM1 exposure and GC incidence has not been extensively studied. Data on GC cases from 2013 to 2021 were gathered from 262 hospitals in Gansu, China. Concurrently, data on the normalized vegetation index (NDVI), gross domestic product (GDP), drinking and smoking behavioral index (DSBI), PM1, PM2.5, and PM2.5-1 were collected. Utilizing a Bayesian conditional autoregressive (CAR) combined generalized linear model (GLM) with quasi-Poisson regression, we evaluated the impact of PM1, PM2.5, PM2.5-1, NDVI, DSBI, and GDP on GC morbidity while adjusting for potential confounders. Our analysis indicated that exposure to PM1 (μg/m3) is significantly positively correlated with GC incidence in regions with an overall age-standardized incidence rate (ASIR) >40 (relative risks [RR]: 1.023, 95% confidence intervals [CI, 1.007, 1.039]), male ASIR >50 (RR: 1.014, 95% CI [1.009, 1.019]), and female ASIR >20 (RR: 1.010, 95% CI [1.002, 1.018]). PM2.5, PM2.5-1, DSBI, and GDP were positively correlated with GC incidence, while NDVI was negatively correlated in the study regions. Our findings provided evidence of a positive correlation between PM1 exposure and GC incidence in high-risk areas of GC within arid regions. Further research is warranted to elucidate the complex nonlinear relationships between environmental factors and GC. These insights could inform strategies for improving the control and prevention of GC in Gansu and similar regions.

Specifying the Associations between PM2.5 Constituents and Gastrointestinal Cancer Incidence: Findings from a Prospective Cohort Study in Beijing, China

This study aimed to test the association between PM2.5 and the incidence of gastrointestinal (GI) cancer, and further to detect the primary constituents on this association. A sum of 142,982 participants without GI cancer at baseline were derived from the National Urban Cancer Screening Program in Beijing (2013-2019). The 5 year averaged concentrations of PM2.5 mass and its five constituents, namely, black carbon (BC), ammonium (NH4+), nitrate (NO3-), organic matter (OM), and inorganic sulfate (SO42-), were estimated by using a hybrid machine learning model. The Cox proportional hazard model with fixed effects was used to explore the associations between PM2.5 mass and its constituents with the incidence of GI cancer. The double-exposure linear model, the mixture exposure model of quantile-based g-computation, and an explainable machine learning model were utilized to evaluate the importance of different PM2.5 constituents. Long-term exposure to PM2.5 mass and its constituents was linearly associated with GI cancer; the estimated hazard ratio and 95% confidence interval (95% CI) of per standard deviation increment were 1.367 (95% CI: 1.257 to 1.487) for PM2.5 mass, 1.434 (95% CI: 1.307 to 1.574) for BC, 1.255 (95% CI: 1.169 to 1.349) for NH4+, 1.217 (95% CI: 1.139 to 1.301) for NO3-, 1.410 (95% CI: 1.287 to 1.546) for OM, and 1.410 (95% CI: 1.288 to 1.542) for SO42-. By using multiple methods, results indicated that SO42- and BC were the most important constituents. Results indicated that long-term exposure to PM2.5 was associated with a high incidence of GI cancer, and BC and SO42- were robustly identified as the primary constituents.

Long-term exposure to air pollution and incidence of gastric and the upper aerodigestive tract cancers in a pooled European cohort: The ELAPSE project

Air pollution has been shown to significantly impact human health including cancer. Gastric and upper aerodigestive tract (UADT) cancers are common and increased risk has been associated with smoking and occupational exposures. However, the association with air pollution remains unclear. We pooled European subcohorts (N = 287,576 participants for gastric and N = 297,406 for UADT analyses) and investigated the association between residential exposure to fine particles (PM2.5), nitrogen dioxide (NO2), black carbon (BC) and ozone in the warm season (O3w) with gastric and UADT cancer. We applied Cox proportional hazards models adjusting for potential confounders at the individual and area-level. During 5,305,133 and 5,434,843 person-years, 872 gastric and 1139 UADT incident cancer cases were observed, respectively. For gastric cancer, we found no association with PM2.5, NO2 and BC while for UADT the hazard ratios (95% confidence interval) were 1.15 (95% CI: 1.00-1.33) per 5 μg/m3 increase in PM2.5, 1.19 (1.08-1.30) per 10 μg/m3 increase in NO2, 1.14 (1.04-1.26) per 0.5 × 10-5 m-1 increase in BC and 0.81 (0.72-0.92) per 10 μg/m3 increase in O3w. We found no association between long-term ambient air pollution exposure and incidence of gastric cancer, while for long-term exposure to PM2.5, NO2 and BC increased incidence of UADT cancer was observed.

Ezrin's role in gastric cancer progression: Implications for immune microenvironment modulation and therapeutic potential

At present, surgical resection is the most effective method for the treatment of gastric cancer. However, death caused by inoperable metastasis is still very common, despite research in this area. The mechanisms underlying the occurrence, development, and metastasis of gastric cancer are not fully understood. Ezrin, a plasma membrane-microfilament junction participates in a variety of cellular activities and is closely related to tumorigenesis and development. Few studies have explored the relationship between the tumor immune microenvironment and ezrin expression in gastric cancer. In this study, we used proteomic techniques to analyze the differentially expressed proteins between the gastric cancer cell lines MKN-45 and HGC-27 and screened ezrin as the target protein. We collected patient information from The TCGA and GEO databases, and the results showed that ezrin was positively correlated with adverse clinical features. We further explored the relationship between ezrin expression levels, immune microenvironment, and genomic changes. We found that ezrin was involved in immune regulation and genomic instability in gastric cancer. When the expression of ezrin is high, immune cell infiltration also increases. We also predicted that ezrin is closely related to immunotherapy and chemosensitivity. Single-cell transcriptome data showed that the ezrin gene was mainly expressed in B cells and epithelial cells, and the expression of EZR in these epithelial cells was positively correlated with the epithelial-mesenchymal transformation pathway and Pi3k-AKT pathway score. Through functional verification of the stably transfected cell line constructed by lentivirus, the results of the liver metastasis model in nude mice suggested that high expression of ezrin leads to the formation of more metastatic foci. In summary, our results clarify the prognostic, immunological, and therapeutic value of ezrin in gastric cancer and provide a theoretical basis for more accurate treatment.