BALTIMORE, Sept. 21 (UPI) -- A new biology, diagnosis and treatment guide issued by U.S. researchers finds that lung cancer in those who have never smoked is different from that of smokers.
Dr. Charles M. Rudin of The Johns Hopkins Kimmel Cancer Center in Baltimore said exposures to second-hand smoke and radon gas are thought to play important roles in causing the disease in never-smokers.
Radon, which leaks into homes from naturally occurring uranium in soil, is known to be the leading cause of such cancers in U.S. populations, but in about half of never-smokers, lung cancer cannot be explained by known risk factors identified in the guide -- which also include asbestos, indoor wood-burning stoves and aerosolized oils caused by cooking.
"It is becoming increasingly clear that the genetic, cellular, and molecular nature of lung cancer in many never-smokers is different from that of smoking-related lung cancers, and there is good evidence now that the best treatment and prevention strategies for never-smokers may be different as well," Rudin said in a statement.
The guide, published in Clinical Cancer Research, resulted from a two-day meeting of 13 lung cancer experts who convened at Johns Hopkins in 2007. The committee reviewed available evidence from several hundred studies published by experts.
Lung cancer in never-smokers usually presents at an advanced stage with non-specific symptoms like cough and chest pain, and is often incorrectly treated as a respiratory illness with antibiotics and asthma medications, Rudin said.