Lung cancer in coal-miners.

In a study of coal-miners suffering from lung cancer two features of special interest are recorded. The difficulties in diagnosis are illustrated by case reports. The two-year survival rate after surgical removal of the tumour is significantly better in coal-miners than in non-miners. After operation 87% of coal-miners were alive two years later, compared with only 36% of other patients operated upon. It is suggested that the rate of spread of the tumour to the mediastinal structures, lymph glands, and blood vessels is retarded by the effects of pre-existing dust disease in the lungs. This factor explains the'good results in a group of patients selected for surgery.