Passive exposure leads more nonsmokers to lung cancer

4/4/2014, 6:45 a.m.

Lung cancer is not just a disease of smokers as more and more nonsmokers are developing lung cancer.

Rathi Pillai

Rathi Pillai

Dr. Rathi Pillai, Emory University’s assistant professor in the Division of Hematology and Medical Oncology, said some patients who are diagnosed with lung cancer have never smoked a cigarette.

“We now understand that exposure to secondhand smoke can cause lung cancer,” Pillai said. “In fact, even passive exposure to tobacco smoke increases your risk for developing lung cancer.”

While cigarette smoking is the main risk factor for most patients who develop lung cancer, secondhand smoke is responsible for 3,000 lung cancer-related deaths a year in the United States. There is also a 20 percent to 30 percent increased risk for nonsmokers living with a smoker.

The high incidence of secondhand smokers getting cancer has prompted many cities to pass laws to limit smoking in restaurants, bars and clubs, the Georgia Department of Public Health says. Many workplaces also are becoming tobacco-free to protect the health of their employees.

Other factors that play into lung cancer among nonsmokers:

n Other environmental exposures besides tobacco smoke have been associated with lung cancer including chemicals used in some workplaces, such as asbestos, tar and soot, and heavy metals like chromium, nickel and arsenic. There also has been an association with radon gas and lung cancer, especially in people exposed to high levels of radon, such as uranium miners. People who have been exposed to large doses of radiation, like atomic bomb survivors in Japan, also have a higher risk of lung cancer. It is still unclear how much of a factor air pollution plays.

n Family history also can impact chances of being diagnosed with lung cancer. There is almost a twofold increased risk of lung cancer in a person with a family history and this risk is even higher if more than two relatives in a family have lung cancer. Researchers still have not identified a particular gene that is passed on in these families that makes them more prone to lung cancer; however, at Winship Cancer Institute of Emory University, genetic testing is now given to every patient diagnosed with lung cancer to identify specific mutations in tumor tissue that may inform treatment decisions.

n Research has identified genetic mutations in lung cancers from people who have never smoked or are/were light smokers. These mutations are not inherited, rather they originate in the lung tissue and create lung cancer.

Mutations in the epidermal growth factor and ALK genes have been found more frequently in lung cancer patients who never smoked. These patients can be treated with drugs that target these specific mutations.

For more information, visit http://dph.georgia.gov.