An ecological analysis of associations between ambient air pollution and cancer incidence rates in Taiwan.

Air pollution is deemed a human carcinogen and can be linked to certain types of cancer other than lung cancer. The present study aimed to investigate the pollutant-cancer associations in a population-level cohort. We obtained the annual age-standardized incidence rates of 28 different cancer types between 2015 to 2019 from the Taiwan Cancer Registry. Outdoor concentrations of particulate matter with a diameter of 10 µm or less (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ground-level ozone (O3), and carbon monoxide (CO) between 2001 to 2010 were retrieved from the Taiwan Air Quality Monitoring Network. Weighted quantile sum (WQS) regression models were used to determine the combined effects of five air pollutants on the relationship to cancer incidence rates after controlling for sex ratio, age, average disposable income per household, overweight/obesity prevalence, current smoking rate, and drinking rate. Trend analyses showed that NO2 and CO concentrations tended to decrease, while SO2 concentrations increased in some counties. WQS regression analyses revealed significantly positive correlations between air pollutants and liver cancer, lung and tracheal cancer, colorectal cancer, thyroid cancer, kidney cancer, and small intestine cancer. Altogether, the results from this ecological study unravel that exposure to ambient air pollution is associated with the incidence of several non-lung cancer types.

Acute exposure to diesel particulate matter promotes collective cell migration in thyroid cancer cells.

Several ecological studies suggest that ambient air pollution is associated with the occurrence of thyroid cancer. In this study, we used certified diesel particulate matter as a proxy for fine particulate matter. Human thyroid cancer cell lines 8505C and TPC-1 were incubated with different concentrations of NIST1650b for 5 days and subjected to functional assays. We found that NIST1650b treatment did not affect short-term cell growth but reduced colony formation at high concentrations. Notably, NIST1650b-treated cells showed altered morphology toward cluster coalescence following treatment. Wound healing assays revealed that leading-edge cells formed protruding tips while maintaining cell-cell adhesion, and a significantly higher ratio of wound closure following treatment at 10 µg/mL was seen in both cell lines. A weak stimulatory effect on transwell cell migration was observed in 8505C cells. Taken together, our results suggest that fine particulate matter induced a coherent phenotype accompanied by augmented collective cell migration in thyroid cancer cells.

Impact of social and economic factors on global thyroid cancer incidence and mortality.

PURPOSE: The incidence of thyroid cancer has increased substantially over the past few decades and is partially explained by overdiagnosis. Geographical variations in incidence rates were reported to be related to national development status. This study aimed to gain deeper insights into global thyroid cancer burden by incorporating additional social and economic factors to account for cross-national disparities. METHODS: We performed a multivariate analysis of age-standardized incidence and mortality data from the GLOBOCAN 2020 database for 126 countries that had more than 100 incident cases of thyroid cancer. The human development index (HDI), current health expenditure, and additional Global Health Observatory indicators were extracted from multiple sources. RESULTS: Age-standardized incidence was highly correlated with HDI (standardized coefficient beta = 0.523, 95% confidence interval [CI] = 0.275-0.771) among the countries studied. The prevalence of raised fasting blood glucose was associated with age-standardized mortality (beta = 0.277, 95% CI = 0.038-0.517). Generally, the mortality-to-incidence ratio was higher in males than in females. In multivariate analysis, HDI (beta = - 0.767, 95% CI = - 0.902 to - 0.633), current health expenditure (beta = 0.265, 95% CI = 0.137-0.394), and fine particulate matter (PM2.5) concentrations (beta = 0.192, 95% CI = 0.086-0.298) were associated with mortality-to-incidence ratios. CONCLUSIONS: National developments gauged by HDI explain the majority of the variation in incidence rates of thyroid cancer but play a smaller role in disparities in mortality rates. The association between air pollution and thyroid cancer outcomes warrants further investigation.

Trends in thyroid cancer burden in Taiwan over two decades.

PURPOSE: Thyroid cancer incidence has increased over recent decades with considerable geographic variations in incidence patterns. Here, we analyzed temporal trends in the incidence and mortality rates of thyroid cancer in Taiwan. METHODS: We obtained age-standardized rates at a national level using data from the Taiwan Cancer Registry annual reports from 1995 to 2019. Trends in age-standardized rates were characterized by joinpoint regression analysis. RESULTS: The age-standardized incidence rate of thyroid cancer increased from 3.00 per 100,000 person-years in 1995 to 15.46 per 100,000 person-years in 2019 (p < 0.001). Significant upward trends were observed in virtually all age groups, including adolescents and the geriatric population. The average annual percent changes were 7.97%, 2.60%, 2.77%, and 1.43% for papillary, follicular, medullary, and anaplastic thyroid cancers, respectively. The mortality rate from thyroid cancer decreased over time in women but remained stable in men. CONCLUSION: The incidence rates of thyroid cancer have steadily increased across gender, age groups, and tumor types over the past two decades. Future studies are needed to investigate potential etiological factors other than overdiagnosis that may drive these trends.