The National Lung Screening Trial (NLST) aimed to determine whether low-dose helical computed tomography (CT) could reduce mortality from lung cancer. The study enrolled 53,454 high-risk participants at 33 U.S. medical centers and randomly assigned them to receive three annual screenings with either low-dose CT or single-view posteroanterior chest radiography. The trial found that low-dose CT screening reduced lung cancer mortality by 20.0% compared to radiography, with a relative reduction in mortality from any cause of 6.7%. The majority of positive screening results were false positives, but complications from diagnostic procedures were rare. The study highlights the potential benefits of low-dose CT screening for lung cancer, but also emphasizes the need for rigorous evaluation of its cost-effectiveness and long-term safety.The National Lung Screening Trial (NLST) aimed to determine whether low-dose helical computed tomography (CT) could reduce mortality from lung cancer. The study enrolled 53,454 high-risk participants at 33 U.S. medical centers and randomly assigned them to receive three annual screenings with either low-dose CT or single-view posteroanterior chest radiography. The trial found that low-dose CT screening reduced lung cancer mortality by 20.0% compared to radiography, with a relative reduction in mortality from any cause of 6.7%. The majority of positive screening results were false positives, but complications from diagnostic procedures were rare. The study highlights the potential benefits of low-dose CT screening for lung cancer, but also emphasizes the need for rigorous evaluation of its cost-effectiveness and long-term safety.