Chest x ray screening for lung cancer at three British chromates plants from 1955 to 1989.

Chest x ray screening for lung cancer had been undertaken over a period of 34 years, initially at yearly intervals, then at eight-monthly intervals, on chromates workers at three plants in the United Kingdom. A review of the records of 229 employees who were diagnosed as having carcinoma of the lung during the screening programme was conducted. Survival data were available on 124 cases (123 now deceased) who constitute the study population. The cases were analysed by age and regularity of attendance for screening. The numbers detected by works x ray screening and by other means were determined with five and 10 year survival rates. A modest but predictable improvement in the five year survival of those who attended regularly for radiography was shown. Taking the total population of cases for whom screening was available, no significant improvement in five year survival was found.