Which of the following best describes the typical annual low-dose CT lung cancer screening eligibility criteria?

• A. Age 55–80 years with a 30 pack-year smoking history and currently smoking or quit within the past 15 years.
• B. Age 50–75 with 20 pack-years;
• C. Age 60–85 with 40 pack-years;
• D. Age 40–70 with 10 pack-years.

Answer: (A)

Screening with annual low-dose CT is aimed at people at high risk for lung cancer based on age and smoking exposure. The best criteria describe individuals aged 55 to 80 who have smoked at least 30 pack-years and are either current smokers or quit within the past 15 years. This combination targets those with substantial cumulative tobacco exposure and within an age range where risk is high enough to justify screening, while still including recent quitters who retain elevated risk. The other options either use an inappropriate age range, a lower pack-year threshold, or a longer time since quitting, making them less aligned with the traditional high-risk criteria established by major screening trials.