Cigarette smoke is the leading cause of lung cancer in the United States, accounting for approximately 90 percent of all lung cancer cases. Unfortunately, at this time, there is no reliable test for predicting which smokers are at highest risk for developing lung cancer. It is also difficult to detect lung cancer at an early stage, when treatment might be more effective.

Now, according to a study published April 7 in the journal Science Translational Medicine, a team of researchers from around the United States has identified a gene pathway that is activated in the airways of people with lung cancer. Cigarette smoke causes injury to the entire respiratory tract and not just the lung. So, these researchers collected normal tissue from the airways of smokers both with and without lung cancer to study early smoking-induced damage. They found that activity of a gene pathway called phosphatidylinositol 3-kinase (PI3K) is significantly increased only in the airway cells of smokers with lung cancer. In addition, the scientists were able to demonstrate that PI3K activation in the airways was associated only with lung cancer, and not with lifetime smoke exposure, smoking status, or presence of other smoking-related lung diseases.

Lung cancer develops deep in the lungs, but based on the findings of this study, PI3K activation is present even in normal airway cells of smokers with lung cancer. This means that physicians might be able to identify smokers who are at risk for, or already have, lung cancer using a procedure called bronchoscopy to collect cells from their windpipes rather than having to perform more invasive lung tests. It also means that smokers with lung cancer might be diagnosed and treated at an earlier stage of the disease with better outcomes.

Tune in tomorrow to read more about how the findings of this study may help to prevent lung cancer in smokers.

Source:

Science Translational Medicine 7 April 2010.