Lung cancer mortality among a cohort of men in a silicotic register

To examine any association between silicosis and lung cancer, the clinic re cords of a cohort of 1502 silicotic workers diagnosed after 1981 were revie wed. All of the essential data, including occupational exposure, smoking ha bits, radiographic extent of silicosis, and vital status of each subject, w ere noted. The standardized mortality ratio for various causes of death was calculated. Thirty-three patients died from lung cancer, giving a standard ized mortality ratio of 1.94 (95% confidence interval, 1.35 to 2.70). Howev er, smoking accounted for most of the excess of lung cancer deaths among th e silicotic workers in the cohort, and no consistent relationship between l ung cancer mortality risk and either duration of exposure to silica dust or severity of silicosis was observed. There is no conclusive evidence in our data to support the hypothesis that lung cancer may be associated with sil icosis.