At world level, silicosis does not predispose to bronchial cancer. But from region to region, the relationship silicosis-cancer varies and depends on factors other than silica. 2. It has not been proved that silica is cancerigen in laboratory animal. 3. Subjects exposed to silica can also be exposed in other circumstances to known carcerigen agents (ionizing radiations, iron oxides, arsenic, exhaust gases of explosion engins). In Switzerland, it is possible that miners in galeries could breath low concentrations of radon and benzopyrene. But it is very difficult to know to what extent these potential risks are involved. 4. Bronchial carcinoma in silicotic patients does not own any characteristics. It is quite similar to that found in the remainder of the population. On the other hand, its diagnosis and treatment are more difficult because of the presence of silicosis. 5. The fortuitous association of silicosis and bronchial cancer is due to overlapping of the profiles of both diseases. The increasing life span of the silicotic patient and the high frequency of bronchial cancer explain why this association is not more exceptional.
