Screening for lung cancer: the US studies.

Efforts in lung cancer screening with chest X-ray (CXR) and sputum cytology in the 1970s and 1980s were negative. In the ensuing decade, the early lung cancer action project (ELCAP), and the Mayo screening study showed the promise of low-dose CT. These and other studies led to the National lung screening study (NLST), which showed definitively that low-dose spiral computed tomography had a measurable impact on mortality and could be justified as a tool for lung cancer screening. This review examines the results of past and recent studies of lung cancer screening.