Lung cancer screening: an update, discussion, and look ahead.

Over the past few years there has been a great deal of debate about the status of lung cancer screening. The debate has focused on at least three areas: the unmet need to prove a mortality reduction from the screening tests being studied, the potential for these screening tests to produce harm, and the possible cost-effectiveness of an image-based screening program. In this manuscript, I review the chest imaging cohort and controlled trials that have been added to the evidence base over the past few years. I then discuss the evidence related to the areas that are currently debated, describe the ongoing trials that will help to clarify these issues, and speculate about the future.