[Lung cancer. Epidemiology and etiologic factors].

Lung cancer is the most frequent cause of death by cancer worldwide. Despite improvements in the treatment the vital prognosis remains poor with an estimated 5-year survival rate of 15 % all stages together. Even if some environmental exposure may favour apparition of the disease, tobacco smoking is by far the greatest risk factor for developing lung cancer. Recent progresses have been made on the identification of cellular mechanisms and genetic abnormalities that make the patients more prone to develop lung cancer.