For ten years, a population of 6,136 male volunteers aged 45 years and over was screened every six months with 70-mm chest photofluorograms and with questionnaires regarding symptoms; 121 developed bronchogenic carcinoma. Only 8% of the men with cancer survived five years. Intervals between detection of the cancers and prior films read "negative" for cancer varied with volunteer cooperation. The five-year survival rate was 12% for 67 men whose tumors were detected within six months of a negative roentgenogram and 4% for 54 with intervals exceeding six months. In each of these two groups, some cases were found by the screen and some came to medical attention as a result of clinical illness. When cancer was detected by the screen, the survival curves were similar regardless of the interval between detection and the prior negative roentgenogram.
Boucot KR, Weiss W. Is Curable Lung Cancer Detected by Semiannual Screening?. JAMA. 1973;224(10):1361-1365. doi:10.1001/jama.1973.03220240015004