A. The idea of screening for lung cancer is appealing, because it has the potential of finding the cancer earlier, when it’s easier to treat. But screening carries risks that may outweigh the benefits for everyone except those at higher than average risk for lung cancer, often heavy smokers. A type of CT scan known as low-dose spiral CT (or helical CT) has shown some promise in detecting early lung cancers in heavy smokers and former smokers. But a drawback of the scan is that it finds a lot of abnormalities that turn out not to be cancer but that still need to be assessed to be sure. This may lead to additional scans or even more-invasive tests such as needle biopsies or even surgery to remove a portion of lung in some people. A small number of people who do not have cancer or have very early stage cancer have died from these tests. There is also a risk that comes with increased exposure to radiation. These factors, and others, need to be taken into account by people and their doctors who are considering whether or not screening with spiral CT scans is right for them. The American Cancer Society has interim guidance on lung cancer screening.