Computed tomography screening for lung cancer: principles and results.

In modern healthcare, one of the most public, most important, and at the same time complicated and scientifically demanding topics is screening for a cancer. Mammographic screening for breast cancer has been, in the last few years, a particularly hotly disputed topic in scientific and public policy circles, with similar confusion and frustration widely reported and thus disseminated by the mass media. Most remarkably, this debacle has taken place against the backdrop of, and despite,a truly enormous amount of completed research designed to address the usefulness of such screening. To avoid a "mammography" debacle for lung cancer, the fundamental principles of screening need to be presented as we have come to think of them. Although it is generally accepted that low-dose computed tomography (CT) screening leads to early diagnosis of lung cancer in a high percentage of the cases, the logical consequence of the current knowledge is that annual CT screening prevents death from lung cancer. Thus, it is not whether CT screening is effective, rather the magnitude of its benefit which needs to be determined. We will illustrate our approach by discussing the Early Lung Cancer Action Project and its New York and International sequels.