Screening for lung cancer

In 1968, the first of three screening projects employing chest x-ray and sputum cytology was begun at Johns Hopkins. Subsequently, Mayo Clinic and Preventive Medicine Institute were added to form the Early Lung Cancer Detection Group. The Johns Hopkins and Mayo Clinic projects employ a chest x-ray annually for all participants and a quarterly sputum cytology for the study group. The Mayo Clinic utilizes a chest x-ray and sputum cytology quarterly for the study group and follow-up only for the comparison group. Entry in the study requires a screening examination for all participants, and those who have lung cancer at the initial examination constitute a "prevalence" group. Those who do not have a lung cancer at the initial examination are randomized into study and comparison groups. The goal was to determine if mortality from lung cancer could be reduced and if so, how much? That evaluation is not yet available. Prevalence data and incidence rate, stage at diagnosis, and survival by stage are now available. The diagnostic value of each modality, chest x-ray, and sputum cytology has been determined and varies by tumor cell type and location.