Lung Cancer

            
             I am doing my report on lung cancer so I can learn the effects, symptoms and .
             prevention's that I can take to avoid getting this disease. Cancer is a disease in which .
             cells multiply without control, destroy healthy tissue, and endanger life. About 100 kinds .
             of cancer attack human beings. Lung cancer is the leading cause of cancer deaths in the .
             United States, among both men and women. Lung cancer claims more lives then colon, .
             prostate and breast cancer combined. In 1999 about 91,000 men and 68,000 women died .
             of lung cancer. The peak age for lung cancer is 65years for men and 70 years for woman. .
             The disease is uncommon before the age of 40. The exact cause of lung cancer remains .
             unclear. .
             Some risk factors of this disease include tobacco smoking, exposure to .
             carcinogenic and industrial air pollutants and genetic predisposition. Lung cancer is also .
             among the most preventable of all cancers. Smoking alone accounts for about 85 percent .
             to 90 percent of lung cancer cases. Although the mortality rate for men has decreased the .
             rate for women has increased. One reason may be that although smoking rates have .
             decreased overall, the rate decreased more rapidly for men. However new cases of lung .
             cancer in women have been declining, which means that their mortality rate is likely to .
             decline in the future. .
             According to the Medical and Health Encyclopedia various theories .
             Rocca 2.
             have been proposed to explain the mechanism by which smoking causes cancer in human .
             beings; none has been proved. However it is known that the lungs of some cigarette .
             smokers show tissue changes before cancer appears, changes apparently caused by .
             irritation of the lining of the bronchi. Physicians believe these changes can be reversed .
             before the onset of cancer if the source of irritation "smoking" is removed.