Clinical Question

Does low-dose computed tomography (CT) screening for lung cancer reduce lung cancer–related mortality and what are the harms?

Evidence-Based Answer

Low-dose CT screening decreases deaths from lung cancer in people 40 years and older with an absolute risk reduction of approximately 0.4% and a number needed to screen of approximately 226 people over an average of 8.8 years of follow-up to prevent one death. Low-dose CT screening is associated with harms, including overdiagnosis and false-positive results, with a number needed to screen to produce one harmful outcome of approximately 44.¹ (Strength of Recommendation: A, systematic review of randomized controlled trials.)

Practice Pointers

Lung cancer is the leading cause of cancer-related death in the world, with an estimated 139,600 lung cancer deaths in the United States in 2019.^2,3 Tobacco smoking is the most significant risk factor for developing lung cancer. Low-dose CT screening is an established tool used to detect lung cancer at an early stage.⁴ The authors of the Cochrane review sought to determine if low-dose CT screening reduces lung cancer–related mortality and the possible harms associated with screening.¹