Lung cancer screening: making the transition from research to clinical practice

The purpose of this review is to examine the literature on lung cancer screening with an emphasis on the prevalence of cancer in screen-detected nodules. On the basis of the evidence, we will then develop a practical approach to screen-detected lung nodules.

The first large randomized controlled trial using low-dose computed tomography (LDCT) found that persons undergoing three annual screening examinations with LDCT had a 20% relative reduction in lung cancer mortality as compared with those screened with annual chest X-rays. The probability of cancer in screen-detected nodules depends on their size and whether the nodules are detected on prevalence or incidence screens. The probability of cancer in screen-detected nodules ranges from 2.4 to 5.2%. Management strategies for screen-detected nodules that have been used successfully include careful observation using serial CT imaging, CT-guided fine needle biopsy, and surgery in carefully selected cases. The most frequently used strategies involve serial CT imaging and CT-guided biopsy for larger nodules and those that demonstrate growth on follow-up.

There is now evidence that LDCT in carefully selected high-risk populations can lead to better outcomes but the cost effectiveness of mass screening with LDCT is still unknown. Only patients at high risk for cancer should be screened.