Cigarette smoking is the leading risk factor for most patients who develop lung cancer. However, some patients diagnosed with lung cancer have never smoked a cigarette. Physicians today are seeing more non-smokers and light smokers with lung cancer. Why do these people get lung cancer?
We understand that exposure to secondhand smoke can cause lung cancer. In fact, even passive exposure to tobacco smoke increases your risk of developing lung cancer. Secondhand smoke is responsible for 3,000 lung cancer-related deaths a year in the United States. There’s a 20 to 30 percent increased risk of developing lung cancer for non-smokers living with a smoker. This is why so many cities have passed laws to limit smoking in restaurants, bars and clubs. Many workplaces are also becoming tobacco-free to protect the health of their employees.
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 has also been an association with radon gas and lung cancer, especially in people exposed to high radon levels, such as uranium miners. It is still unclear how much of a factor air pollution plays in developing lung cancer.
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. At Winship Cancer Institute of Emory University, genetic testing is performed for every patient with stage four non-small cell lung cancer to identify specific mutations in tumor tissue that may inform treatment decisions.
Some of the mutations found more frequently in light/never smokers include epidermal growth factor receptor (EGFR), ALK, ROS-1, and RET genes, among others. These patients can be treated with oral drugs that target these specific mutations. Ongoing research at the Winship Cancer Institute of Emory University is helping us understand more about these genetic changes, and other factors will help us treat all patients with lung cancer with better, more personalized treatments.
About Winship Cancer Institute of Emory University
Winship Cancer Institute of Emory University is Georgia’s only National Cancer Institute-designated Comprehensive Cancer Center, a prestigious distinction given to the top 3% of cancer centers nationwide for conducting cancer research and providing training that is transforming cancer care, prevention, detection and survivorship. Winship discovers, develops, delivers and teaches some of the world’s most effective ways to prevent, detect, diagnose and treat each patient’s unique cancer. Cancer care at Winship includes specialists with deep expertise and experience in cancer; multidisciplinary evaluation, treatment planning and care coordination that caters to each patient’s individual needs; therapies supported by the latest advances in cancer research; and comprehensive clinical trials and support services.
About Dr. Carlisle
Jennifer W. Carlisle, MD, is an assistant professor in the Department of Hematology and Medical Oncology at Emory University School of Medicine. A board-certified medical oncologist, Dr. Carlisle specializes in the care of patients with lung cancer, mesothelioma, and thymic malignancies at Winship Cancer Institute. Her research interests include translational studies that advance the understanding of immunobiology and immunotherapies.