A new study in the New England Journal of Medicine has found that screening for lung cancer with low-dose spiral computed tomography (CT) does reduce mortality; however, the screening method s high rate of false positives means that it should be used judiciously.
In a study led by Dr. Christine Berg of the National Cancer Institute for the multi-institute National Lung Screening Trial Research Team, over 53,000 people at high risk for lung cancer (meaning smokers, or recent ex-smokers) were randomly assigned to undergo three annual screenings with either low-dose CT or as a control group simple chest radiography. The screenings occurred between 2002 and 2004, and data collected through 2009 revealed a 20 percent reduction in lung cancer mortality and a nearly seven percent decrease in all-cause mortality among patients who received CT scans. Both methods, however, resulted in a high rate of false positives: over 96 percent for the CT group, and over 94 percent for the chest radiography group.
Because of the physically invasive tests and the psychological stress that can result from a false positive, ACSH s Dr. Gilbert Ross believes that patients should discuss their risks for lung cancer with a physician before undergoing a CT screening. There is actually a much higher risk for a false positive result than for a lung cancer diagnosis, says Dr. Ross. That said, he continues, lung cancer is an awful disease, so it s very important to take into account the pack-year status of the patient number of cigarettes per day multiplied by the years of smoking and the length of time since quitting, if a former smoker, when deciding whether to have a CT screening.