Lung cancer screening: an update.

Two prominent and timely issues in lung cancer screening are discussed in this article. First, findings from extended mortality follow-up of participants enrolled as part of the Mayo Lung Project are reviewed. These findings suggest that overdiagnosis-the identification, through screening, of clinically unimportant lung cancer lesions-may occur when screening for lung cancer. Second, the question of whether sufficient evidence exists to advocate mass lung cancer screening with low radiation dose spiral computed tomography (CT) is discussed. Given the absence of lung cancer mortality data for spiral CT, it is concluded that such activities should not be advocated at this point in time. The Lung Screening Study, an ongoing randomized controlled trial of lung cancer screening with spiral CT, also is described.