Our previous study, china lung cancer screening study version 1.0, had proven that LDCT led to a 74.1% increase in detecting early-stage lung cancer compare to usual care (NCT02898441). The present one arm study is performed to evaluate the efficacy of new techniques in improving the implementation of lung cancer screening and validate our previous findings. 6000 high-risk subjects (age 45-75) were recruited to take LDCT screening. (Baseline + 2 biennial repeated LDCT screening). Follow-up for lung cancer incidence, lung cancer mortality and overall mortality was performed. Blood samples were stored in a Biobank. Management of positive screening test was carried out by a pre-specified protocol.

Inclusion Criteria:

• Eligible participants were those aged 45-75 years, and with either of the following risk factors:

  1. history of cigarette smoking ≥ 20 pack-years, and, if former smokers, had quit within the previous 15 years;
  2. malignant tumors history in immediate family members;
  3. personal cancer history;
  4. professional exposure to carcinogens;
  5. long term exposure to second-hand smoke;
  6. long term exposure to cooking oil fumes.

Exclusion Criteria:

1. Had a CT scan of chest within last 12 months
2. History of any cancer within 5 years