Lung cancer screening: examining the issues.

Abstract

The goal of screening is to detect disease at a stage when cure or control is possible, thereby decreasing disease-specific deaths in the population. Many studies have attempted to demonstrate that lung cancer screening using chest radiography or computed tomography (CT) identifies patients with lung cancer and reduces cancer-related mortality. Until recently, there was no evidence confirming a reduction in disease-specific mortality with screening. Early cancer screening should result in a gradual population-wide stage shift toward earlier cancer stages over time, but stage shifting was not reported in early lung cancer screening studies. Lead-time, length-time, and overdiagnosis biases may each have an impact on screening studies reporting survival as an outcome. In this past year, the National Lung Screening Trial reported a significant reduction in cancer-related mortality as a result of screening with chest CT imaging. This will shape the direction of future screening programs.