Screening for lung cancer in high-risk groups is beneficial for early detection of early lung cancer and improves the cure rate. Low-dose CT ( low-dose
computedtomography (LDCT) is 4-10 times more sensitive than conventional chest radiography in detecting early stage lung cancer, and can detect early peripheral lung cancer early. Data from the International Early Lung Cancer Action Plan show that annual screening with LDCT can detect 85% of stage I peripheral lung cancers, with an expected survival rate of 92% at 10 years after surgery. The U.S. National Lung Cancer Screening Trial demonstrated that LDCT screening reduced lung cancer mortality by 20%, making it the most effective lung cancer screening tool available. Risk assessment factors for lung cancer screening proposed in the National Comprehensive Cancer Network guidelines include smoking history (current and past), history of radon exposure, occupational history, history of cancer, family history of lung cancer, history of disease (chronic obstructive pulmonary disease or tuberculosis), and history of smoke exposure (passive smoking exposure). Risk status was divided into 3 groups: (1) high-risk group: age 55-74 years, history of smoking ≥ 30 packs/year, history of quitting smoking <
15 years; or age ≥50 years, history of smoking ≥20 packs/year, with additional risk factors other than passive smoking. (2) Intermediate risk group: age ≥ 50 years, history of smoking or passive smoking exposure ≥ 20 packs/year, no other risk factors. (3) Low-risk group: age <50 years, history of smoking <20 packs/year. The guidelines recommend lung cancer screening for the high-risk group, and do not recommend screening for the low- and intermediate-risk groups.