The National Lung Screening Trial (NLST) showed a reduction in deaths from low-dose CT screening compared to CXR screening. (CXR screening is known to be ineffective at reducing deaths from lung cancer.)
53,454 current and former smokers who quit within the past 15 years, 55-74 years of age, with at least 30 pack-years of smoking were randomly assigned to be screened once a year for 3 years with low-dose CT or CXR.
Participants must have had no symptoms or signs of lung cancer or other serious medical conditions, and be medically fit for surgery. After 6.5 years of follow-up there were 3 in 1,000 fewer lung cancer deaths in the CT screening group, on average. (21 in 1,000 lung cancer deaths in the CXR group vs. 18 in 1,000 in the CT group.)
These findings represent an average benefit, and benefits actually vary dramatically. Consider the benefit for sample patients on the following pages.