Lung cancer screening is a way in which doctors check the lungs for early signs of cancer in people who have no symptoms of lung cancer. Doctors suggest it for certain people who are at high risk of lung cancer because they smoke or used to smoke. Although screening is not likely to be helpful for all smokers, doctors do think it might help prevent cancer deaths in some heavy smokers, or those who smoked for many years (even if they have already quit).
Researchers have been studying chest X-rays and low-dose CT scans, two types of imaging tests, to see if they are good screening tools. Imaging tests create pictures of the inside of the body. A low-dose CT scan uses much less radiation than a normal CT scan and shows a more detailed image of the lungs than a standard X-ray. It turns out that X-rays do not work for screening. Low-dose CT scans, on the other hand, might be helpful screening tools for some people at high risk of lung cancer.
The goal of lung cancer screening is to find cancer early, before it has a chance to grow, spread or cause problems. One large study found that smokers who were screened with low-dose CT scans were less likely to die of lung cancer than those who were screened with standard X-ray. Even so, experts are not yet ready to recommend low-dose CT scans for all heavy smokers. That's because it's unclear whether screening outside of a research study—in the "real world"—would work as well. Plus, screening comes with certain risks, including the need for more tests if a person has an abnormal screening test.
The best way to lower your chances of getting or dying from lung cancer is to quit smoking. It does not matter how much or how long you have smoked. Quitting now will reduce your chances not only of lung problems, but also of heart disease and many forms of cancer.