Screening for Lung Cancer with Low-Dose Computed Tomography

Goo, Jin Mo

Abstract

Lung cancer is the leading cause of cancer deaths in Korea. It is hoped that the screening for lung cancer will reduce the mortality from these kinds of tumors, which are characterized by a dismal overall survival, relatively well defined risk groups and a lack of early symptoms. The past studies, using sputum cytology and chest radiography, have failed to demonstrate any reduction in lung cancer mortality through screening. The goal of lung cancer screening, with computed tomography (CT), was the detection of small cancers, presumably when they are in the biologically early stages of their evolution, and amendable to surgical cure. Low-dose CT has been shown to have a much higher sensitivity for small pulmonary nodules, but small pulmonary nodules are common, and most are not malignant. Non-invasive diagnostic algorithms are required to correctly classify the detected lesions, and to avoid invasive procedures with benign nodules. Based on these diagnostic algorithms, preliminary studies of low-dose CT, in heavy smokers, have demonstrated a high proportion of asymptomatic, early, resectable cancers. However, reductions in the mortality due to lung cancer screening, with low-dose CT, have still to be demonstrated. Several randomized controlled trials are under way to assess the possible reduction in the mortality by comparison of the mortalities in screening and control groups.