Correlation Between Short-Term Exposure To PM_2.5,Inflammatory Factors And Lung Cancer

Background:Lung cancer is one of the most common cancers in the world with high morbidity and mortality.At present,the pathogenesis of lung cancer is unknown,and it is mainly believed to be related to smoking,air pollution,exposure to occupational carcinogens and genetic factors.Among air pollution,the pollutant most closely associated with lung cancer is PM_2.5.The mechanisms by which PM_2.5contributes to the development of lung cancer are unclear,but numerous studies have found a strong association between changes in inflammatory factor levels and the deleterious health effects caused by PM_2.5exposure.Therefore,in this study,we conducted a case-control population study to investigate the relationship between short-term exposure to PM_2.5,inflammatory factors,and lung cancer.Objective:To investigate the relationship between PM_2.5short-term exposure,inflammatory factors and lung cancer and to reveal the possible role of inflammatory factors in PM_2.5short-term exposure affecting lung cancer.Methods:Case-control study,select 295 patients with lung cancer from September2021 to October 2022 at the Sixth Clinical School of Guangzhou Medical University as the case group and 329 non-oncology patients admitted to the hospital during the same period as the control group.Questionnaires were combined with clinical data to collect Baseline data of subjects and blood samples.The Flow cytometry was used to analyze the levels of related inflammatory factors in the blood of the subjects.Collect data of PM_2.5concentration monitoring stations in Qingyuan City and its surrounding areas from August 2021 to October 2022,use the inverse interpolation method to evaluate the subjects PM_2.5exposure levels on the day of blood collection and in the preceding 7 days.The relationship between PM_2.5exposure and lung cancer,blood inflammatory factor levels and lung cancer was analysed using logistic regression,and the relationship between PM_2.5short-term exposure and blood inflammatory factor levels was analysed using multiple linear regression.Mediation analysis was used to further explore the possible role of blood inflammatory factor levels in the association between PM_2.5and lung cancer.Results:Case group versus control group,PM_2.5was associated with a 1.7%（OR=1.017,95%CI:1.002 to 1.032）increased risk of lung cancer for each additional quartile spacing at the 3-day lag level,a 2%（OR=1.021,95%CI:1.007 to1.035）increased risk of lung cancer for each additional quartile interval at 4-day lag;and a 1.7%（OR=1.017,95%CI:1.003～1.032）increased risk of lung cancer for each additional quartile spacing at the 5-day lag level.Multiple linear regression was used to analyse the association between PM_2.5short-term exposure and inflammatory factors,and in the control group,IFN-γwas found to change at each interquartile spacing increase in PM_2.5exposure concentration between 2 and 5 days after PM_2.5lag,with levels of change of 1.119%（0.454 to 1.789）,1.102%（0.445 to 1.762）,1.189%（0.549 to 1.833）,0.757%（0.091～1.428）.IL-10 in PM_2.5lagged 2 to 4 days at PM_2.5exposure concentrations changed by 3.190%（1.111～5.312）,4.171%（2.121～6.261）,3.404%（1.401～5.448）for each increasing interquartile interval.TNF-αat PM_2.5lagged 3days at PM_2.5exposure concentrations varied at 2.250%（0.795 to 3.726）for each increasing interquartile interval.IL-17A at PM_2.5exposure concentrations at PM_2.5lagged 1 to 5 days varied at 1.512%（0.541 to 2.491）,1.996%（0.963 to3.040）,1.604%（0.580 to 2.638）,1.863%（0.866 to 2.870）,and 1.415%（0.379 to2.461）.In the case group IL-2,IL-4,IL-10,and TNF-αchanged at each increasing interquartile spacing of PM_2.5exposure concentrations at the 7-day lag time of PM_2.5with levels of-1.772%（-2.817 to-0.716）,-2.321%（-3.911 to-0.704）,23.395%（3.752 to 46.756）,and-1.867%（-3.558 to-0.147）.Using univariate logistic regression analysis,the risk of lung cancer increased with increasing levels of seven blood inflammatory factors.For example,for each quartile spacing increase in IFN-γlevels,the risk of lung cancer increased by 64%（OR=1.639,95%CI:1.311 to 2.066）.Mediation analysis revealed a significant IFN-γmediating effect in the association between PM_2.5short-term exposure lag of 3 days and lung cancer,with a mediating effect of 20.6%（95%CI:5.0%to 98.0%）.IL-17A mediating effect was significant in the association between PM_2.5short-term exposure lag of 3 to 5 days and lung cancer.The mediating effects were 25.5%（95%CI:6.1%to 119.0%）,11.5%（95%CI:1.5%to 47.0%）,and 22.3%（3.5%to 106.0%）,respectively.Conclusion:Short-term exposure to PM2.5 increases the risk of lung cancer,and there is a significant positive correlation with the plasma levels of inflammatory factors.Inflammatory factors IFN-γand IL-17A play an intermediary role in the association between short-term exposure to PM2.5 and lung cancer.The above studies provide clues for exploring the mechanism research on the relationship between health damage caused by PM2.5 exposure.