Since symptoms of lung cancer often do not appear until the disease is advanced, only about 15% of the lung cancer cases are found in the early stages.

Sallye Roth has been smoking for 20 years, and is about to go through her first CT lung scan. "I'm scared, I'm afraid that they'll find something. Hopefully not. But if they do, maybe we'll catch it early."

Dr. Dosani says that the goal of screening is to uncover all lung nodules, some of which will need further exploration. "Most lung cancers are not symptomatic, which means that most patients do not have any complaints when they are early. By the time they start coughing up blood, and start losing weight and have shortness of breath, frequently it is late and the survival rate it not as good."

But catching lung cancer early - when surgery is a treatment option - improves survival substantially, and 70 percent of patients who are diagnosed early may survive at least five years. Chest X-rays alone have not been shown to reduce the death rate from lung cancer. Dr. Donsani also says, "they have a low dose CT scan, which is called spiral CT scan, which is the amount of radiation exposure is very low."

Sallye's scan fortunately turned out to be cancer free. Is she interested in quitting smoking now? "Possibly. Maybe I'll quit."

Lung cancer has to be among the most tragic, that's because in most cases, it can be prevented. In fact 83% of people who develop lung cancer are smokers.

If you're looking for resources that are available to help you quit smoking you can call the American Cancer Society at 1-800-acs-2345.