(RxWiki News) Asbestos is a known cancer-causing agent. It was banned in the United States in the 1970s, but can still be found in old insulation and other building materials. People who have been exposed to asbestos are at higher risk of respiratory diseases, including lung cancer.
When smoking, asbestos and asbestosis (disease caused by asbestos) are combined, the risks of developing lung cancer skyrocket. In fact, all three factors increase a person’s risk by 37-fold.
A recent study found that quitting smoking can significantly reduce these risks.
"Quit smoking - today."
Steven B. Markowitz, MD, DrPH, professor of occupational and environmental medicine at the School of Earth & Environmental Sciences at Queens College in New York, led a study that looked at 2,377 long-term North American insulators and 54,243 male blue collar workers with no history of exposure to asbestos.
Researchers found that asbestos exposure among non-smokers increased lung cancer death rates five times compared to people who had not been exposed to asbestos.
Among smokers who worked with asbestos, the cancer death rate increased by more than 28-fold.
Smokers who had asbestosis had a 37-fold higher rate of dying from lung cancer than non-smokers who had not been exposed to asbestos.
Insulators who quit smoking had significantly lower risks of dying from lung cancer over the next 10 years, according to the study. Death rates dropped from 177 per 10,000 among smokers to 90 per 10,000 among those who had quit smoking.
The authors said the study had some limitations. Smoking status and asbestos exposure were evaluated only once, and length of exposure could have been brief.
“Lung cancer carcinogenesis is complex, but we’ve known for long time that lung cancer is smoking related in most of the cases and that asbestos is a risk factor,” Fred R. Hirsch, MD, PhD, professor of medicine and pathology at the University of Colorado Cancer Center, told dailyRx News.
“The result that a combination of the two factors increase the risk of developing lung cancer is anticipated as more risk factors you are exposed to as more genetic changes (i.e., mutations) you induce.”
“Thus, the data are interesting, but not unexpected even with some limitations in the study design as pointed out by the authors. Of specific interest is of course that insulators who quit smoking have a significant drop in lung cancer development,” Dr. Hirsch said.
Results from this research were published the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
Funding was provided by the Center for the Biology of Natural Systems, Queens College, City University of New York. No conflicts of interest were disclosed.