Lung Carcinoma is most commonly associated with: March 2005

Ans. B: Asbestosis Cigarette smoking is the most impoant cause of lung cancer. About 90% of lung cancers arise due to tobacco use. Other causes of lung cancer include the following: Passive smoking, or secondhand smoke, presents another risk for lung cancer. Air pollution from motor vehicles, factories, and other sources probably increase the risk for lung cancer. Asbestos exposure increases the risk of lung cancer nine times. A combination of asbestos exposure and cigarette smoking raises the risk to as much as 50 times. Another cancer known as mesothelioma (a type of cancer of the lining of the chest cavity called the pleura or of the lining of the abdominal cavity called the peritoneum) is also strongly associated with exposure to asbestos. Lung diseases, such as chronic obstructive pulmonary disease (COPD), also create a risk for lung cancer. A person with COPD has a four to six times greater risk of lung cancer even when the effect of cigarette smoking is excluded. Radon exposure poses another risk. Radon is a by-product of naturally occurring radium, which is a product of uranium. Silicosis is associated with pulmonary fibrosis. X-ray of chest shows rounded opacities in the upper lobes after 15-20 years (simple silicosis). Calcification of hilar nodes may produce 'eggshell' pattern. Beryllium may produce acute pneumonitis, but it is more commonly associated with a chronic granulomatous disease similar to sarcoidosis.