Researchers have found weak evidence supporting an effect of secondhand tobacco smoke exposure on the incidence of lung adenocarcinoma in situ/minimally invasive adenocarcinoma (AIS/MIA), according to a new study published online ahead of print in the journal Cancer Epidemiology, Biomarkers & Prevention.1
The US Department of Health and Human Services estimates that secondhand smoke causes approximately 7330 deaths from lung cancer each year. It also increases the risk for heart attack and stroke and leads to approximately 33 950 deaths from heart disease each year.2
For the study, a team of researchers led by Zuo-Feng Zhang, MD, PhD, professor of Epidemiology at the University of California, Los Angeles, Fielding School of Public Health, analyzed data from 7 case-control studies that were part of the International Lung Cancer Consortium. The researchers identified 625 cases of AIS/MIA and 7403 controls, of which 170 and 3035, respectively, were in never smokers.
Results showed that ever exposure, compared with never exposure, to secondhand tobacco smoke was positively associated with AIS/MIA incidence both overall and in never smokers; however, the researchers note that the results were largely impacted by 1 large study.
“Further studies are needed to assess the impact of secondhand tobacco smoke exposure using the newly recommended classification of subtypes of lung adenocarcinoma,” the authors conclude.
1. Kim CH, Lee Y-C, Hung RJ, et al. Secondhand tobacco smoke exposure and lung adenocarcinoma in situ/minimally invasive adenocarcinoma (AIS/MIA) [published online ahead of print October 26, 2015]. Cancer Epidemiol Biomarkers Prev. doi:10.1158/1055-9965.EPI-15-0436.
2. Health effects of secondhand smoke. American Lung Association Web site. http://www.lung.org/stop-smoking/smoking-facts/health-effects-of-secondhand-smoke.html. Accessed October 28, 2015.