For now, there is only scientific evidence that early detection of lung cancer is sufficiently effective in people who smoke or have smoked and thereby have an increased risk of developing long-term lung cancer. Future research will reveal this further

4-in-the-lung run:
is to examine a large group of people for the presence of a disease. Importantly, it is a study where a relatively small group may have large benefits, while a relatively large group may have smaller drawbacks. Important potential benefits are fewer deaths from lung cancer and more treatments that are relatively less invasive. On the other hand, screening involves exposure to a small amount of X-rays. Also, participation can cause anxiety/uncertainty during the scanning and waiting for the results. It is also possible that an abnormality may be seen, but that after additional testing it does not turn out to be lung cancer (false positive). It is very important that the advantages clearly outweigh the disadvantages: the so-called utility-risk ratio. This is also defined in the Population Screening Act.

In this regard, it is important to know well who is at (greatly) increased risk for the disease. Smoking behavior is an important part of determining lung cancer risk. About 80-90% of lung cancers are related to smoking history. Importantly, at least half of those at high risk have already quit smoking. However, the risk remains high for a long time. Factors such as secondhand smoke and air pollution/exposure to chemicals increase the risk of lung cancer, but we are not currently well positioned to determine when a person is at such a high risk of lung cancer based on these factors that screening may be useful. These factors do get included in analyses, and once such factors can be included, they will certainly be. Until then, it is important to be alert for symptoms that may indicate lung cancer if there is long-term second-hand smoke or exposure to polluted air, for example.