[Risk groups and effective x-ray screening frequency of bronchial cancer]

Mortality from bronchial carcinoma has increased in Czechoslovakia since 1950 to the threefold and has amounted to 47.6/100,000 in 1979. Looking for ways to influence this unfavorable development two epidemiological studies were performed with the aim to find hints to increase the efficiency of mass x-ray screenings. In a study in the district of Kolín 18% of 1,081 new cases of bronchial carcinoma were detected by x-ray-examinations of the whole population performed every 3 years and 10% by yearly repeated x-ray examinations of the groups with pulmonary tuberculous and nontuberculous alterations in dispensaire care. The rates of pulmonary resections and of 5 year survival were higher in those cases detected by periodic miniature x-ray examinations than in patients examined by reason of complaints. In an experimental study, done in a risk collective of heavy smokers compared with a randomized control group from 8 selected districts of Czechoslovakia 75% of bronchial cancer incidence was found by screening repeated every half a year. But the resection rate was not as high as a third of these cases. For a screening programme miniature x-ray examinations are recommendable every 1/2 to 1 year for those groups being in dispensaire care because of a higher risk of bronchial carcinoma.