Under USPSTF guidelines for lung cancer screening, when should annual LDCT screening be discontinued?

• A. If the person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative surgery.
• B. At age 75.
• C. If the person has not had a positive CT result.
• D. After 5 years of screening regardless.

Answer: (A)

The main concept being tested is when USPSTF says to stop annual LDCT lung cancer screening. The best answer says to discontinue if the person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative surgery. This reflects the balance of benefits and harms: if someone quit smoking many years ago or has a serious illness that limits life expectancy or makes curative treatment unlikely or not desired, the potential mortality benefit from screening is minimal and the risks from false positives, unnecessary procedures, and anxiety outweigh any benefit.

Age alone (such as being 75) does not mandate stopping, since the screening age range can include that age. Not having any positive CT results does not automatically end screening, because the decision to continue is based on ongoing risk and the stopping criteria, not prior results. There is no hard 5-year limit, as screening is annual as long as the person continues to meet eligibility and has not reached a stopping criterion.