Findings from a recent study demonstrate that female lung cancer patients who have never smoked have significantly greater exposure rates to outdoor air pollution than female lung cancer patients with a history of smoking.
Renelle L. Myers, British Columbia Cancer Agency, Vancouver, presented these findings today at the International Association for the Study of Lung Cancer’s (IASLC’s) 19th World Conference on Lung Cancer (WCLC) in Toronto, Canada.
The study enrolled 681 patients with newly diagnosed lung cancer, including 439 “ever-smokers” and 242 “never-smokers.”
A detailed residential history was conducted to estimate their air pollution exposure since 1996, when accurate high-resolution concentration estimates of ambient particulate matter (PM2.5) derived from satellite observations and ground measurements became available.
The average PM2.5 exposure was then quantified by combining residential histories with exposure data.
The results of the study showed median air pollution exposure of all cancer patients was 7.1 PM2.5 ug/m3 (IQR 6.8-7.3; Range 4.3-65.8).
Of the ever-smokers, 6.1 percent had a PM2.5 > 10 ug/m3 , whereas more than double – 15.1 percent – of the never-smokers had a PM2.5 > 10 ug/m3 .
Among never-smokers with lung cancer with high PM2.5 exposure >10 ug/m3 , 74 percent were female, and 83 percent were of Asian descent.
Using a logistic regression model, researchers demonstrated a significant association between air pollution exposure and never-smokers compared to ever-smokers in women, an association that was absent in males.
“The results of this study underscore the importance of factoring outdoor air pollution into lung cancer development among women, particularly those who have never smoked,” said Myers. “Although longterm exposure to ambient particulate matter has been associated with an increased risk of developing lung cancer and is estimated to be responsible for almost 25 percent of global lung cancer deaths, there is currently no lung cancer screening risk prediction model that includes air pollution as an individual risk factor in its calculation.”