Generalizability of results from the national lung screening trial

Lung cancer is the major cause of cancerrelated death worldwide, with a 5-year survival of only 16%. Most lung cancer cases are diagnosed at an advanced incurable stage. As earlier stages have a better prognosis, the key to reducing mortality could be early diagnosis of the disease. At present, low-dose computed tomographic (CT) screening has shown promising data. Lung cancer death rates were reduced by 20% when CT screening is compared to chest radiography in a high-risk group. There are many advantages of CT screening in lung cancer, however there are also some important issues that should be taken into account. Therefore, the applicability of the results to clinical practice is not clear yet. In this Commentary we discuss different aspects that play important roles in the balance between harms and benefits of screening, including overdiagnosis, availability of treatment options worldwide, ethical considerations, costs, and prolonged life expectancy. We conclude that clinicians should be cautious in generalizing findings to the total population of smokers and take into account that the use of lung cancer screening in clinical practice may have limitations.