Some results of screening for early lung cancer.

Screening for lung cancer is somewhat controversial in that very few evaluations of the screening process have been made, and even fewer have involved the use of concomitant, unscreened controls. This report of the Mayo Lung Project provides evaluation of a randomly selected 4500 clinic patients, offered screening for lung cancer at four-month intervals for six years. Another 4500 randomly selected controls not offered screening were merely observed. Good screening is defined, the Mayo project is evaluated, and puzzling results are presented and discussed. From the screened group, 98 new cases of lung cancer have been detected, 67 by study screening and 31 by spontaneous reporting of symptoms (15) or by x-ray examinations (16) done in other than study circumstances. From the controls, 64 new lung cancer cases have been detected, 43 by symptoms and 1 by other methods. Lung cancer mortality is 39 for study patients and 41 for controls. There is thus no evidence at this time that early case finding hs decreased mortality from lung cancer.