What is the recommended lung cancer screening criterion?

• A. Annual chest radiograph for adults aged 50-80 with 20+ pack-year history
• B. MRI screening for high-risk individuals
• C. Annual low-dose CT for adults aged 50-80 with 20+ pack-years who currently smoke or quit within 15 years
• D. Low-dose CT every 5 years for adults aged 60-80 with 20+ pack-years

Answer: (C)

Screening for lung cancer should be done only in a clearly defined high-risk group, using an annual low-dose CT scan. The best-supported criterion identifies adults 50 to 80 years old who have a 20 pack-year smoking history and who currently smoke or have quit within the past 15 years. This combination captures those at substantial risk while keeping the balance of benefits and harms favorable, since low-dose CT has been shown to reduce lung cancer mortality in this population and annual testing ensures cancers aren’t missed between longer intervals. Chest radiographs have not demonstrated mortality benefit for screening, MRI is not used for this purpose, and screening every five years or with different age ranges or smoking histories does not align with the evidence supporting annual low-dose CT in this high-risk group.