Lung cancer screening in high-risk groups is beneficial in detecting early lung cancer and improving lung cancer survival rates. Low-dose spiral CT is 4-10 times more sensitive than conventional chest X-ray in detecting early stage lung cancer and can detect peripheral lung cancer at an early stage. Data from the International Early Lung Cancer Action Plan show that annual low-dose spiral CT screening 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 low-dose spiral CT screening reduces lung cancer mortality by 20 percent in high-risk groups and is the most effective lung cancer screening tool available. A recent study from the European Lung Cancer Screening Trial showed a 24% reduction in lung cancer mortality in men and a 33% reduction in lung cancer mortality in women with low-dose spiral CT screening, and in China, low-dose spiral CT is recommended for lung cancer screening in high-risk groups in a few regional pilot technical guidelines for cancer screening and early detection and treatment.
The latest guidelines issued by the National Comprehensive Cancer Network (NCCN) in 2021 suggest risk assessment factors for lung cancer screening, including history of smoking (current and past), history of radon gas exposure, history of occupational exposure (silica, cadmium, asbestos, arsenic, beryllium, chromium, diesel exhaust, nickel, soot and soot) history of malignancy, family history of lung cancer in first-degree relatives, history of chronic obstructive pulmonary gas or pulmonary fibrosis, and history of passive smoking.
The risk status was divided into 2 groups as follows.
1. High-risk group
Age ≥ 50 years, smoking history ≥ 20 pack years.
2. Low-risk group
Age <50 years and/or history of smoking <20 pack years.
The NCCN guidelines recommend lung cancer screening for the high-risk group and not for the low-risk group.
Lung cancer screening is recommended for high-risk groups in the Chinese Lung Cancer Screening Criteria published by the National Cancer Center in 2020 and in the latest Chinese Guidelines for Lung Cancer Screening and Early Diagnosis and Treatment (2021, Beijing) published in 2021. It is recommended that people at high risk for lung cancer should meet one of the following conditions.
(1) Smoking: ≥30 pack-years of smoking, including having smoked ≥30 pack-years but quit for less than 15 years.
(2) Passive smoking: living or working in the same room with a smoker for ≥20 years.
(3) Having COPD.
(4) History of occupational exposure (asbestos, radon, beryllium, chromium, cadmium, nickel, silica, soot and soot dust) for at least 1 year.
(5) Have a first-degree relative with a confirmed diagnosis of lung cancer.
Note 1: Number of pack-years of smoking = number of packs smoked per day (20 packs per day) x number of years of smoking
Note 2: First-degree relatives refer to parents, children and siblings