[Lung cancer in different chronic lung diseases]

The studies performed have indicated that nearly in 50% of cases lung cancer is associated with different chronic lesions of the lung: chronic purulent bronchitis, tuberculosis, chronic pneumonia, pulmonary emphysema and diffuse pneumosclerosis, and these provide favourable conditions for epithelial metaplasia of the bronchi, bronchioli and alveoli with subsequent cell atypism and development of lung cancer.