Lung cancer remains the leading cause of cancer death worldwide, largely because most cases are diagnosed late. Low-dose CT screening aims to find cancer at an earlier, curable stage.
The evidence
The US National Lung Screening Trial showed a 20% relative reduction in lung cancer mortality with low-dose CT compared with chest radiography. The European NELSON trial found a similar benefit, with a reduction in lung cancer deaths of around a quarter in men.
Who is eligible?
Eligibility is based on age and smoking history. The US Preventive Services Task Force (2021) recommends annual screening for adults aged 50 to 80 with at least 20 pack-years who currently smoke or quit within the past 15 years. Other countries use risk-prediction models.
Harms to weigh:
- False positives and anxiety
- Invasive follow-up procedures
- Overdiagnosis of slow-growing cancers
- Incidental findings outside the lungs
Making screening work
Structured nodule management protocols, such as Lung-RADS, standardise reporting and reduce unnecessary follow-up. Programmes work best when they combine screening with smoking cessation support.
“Screening is not a scan — it is a programme.”
This article is for education only and does not replace clinical judgement or local guidelines.
