Lung cancer is the presence of malignant cells (a malignant tumor) in the lungs. These malignant cells grow and spread rapidly, destroying healthy lung tissue in the process. Lung cancer is the result of cancerous lung cells, although cancerous cells of other types can spread to the lungs.
Non-small cell lung cancer is the most common form of lung cancer. Around 80% of lung cancer is of this type. While the cells grow more rapidly than normal cells, the non-small cell lung cancer does not grow as fast as small cell lung cancer, which makes up the other 20%.
One major cause of lung cancer is smoking. Smoking causes about 87% of lung cancer cases. This includes both smokers and those who live or work with smokers, inhaling secondhand smoke on a regular basis.
The next leading cause of lung cancer is radon exposure, coming from the soil beneath homes and buildings. Other forms of exposure that lead to lung cancer include chromium, nickel, arsenic, asbestos, uranium and some petroleum products.
Lung cancer does not have a high cure rate, as compared with certain other forms of cancer. This is mainly because it is hard to detect in the beginning stages. When lung cancer begins, the individual is usually asymptomatic for some time. Unfortunately, for the individual to notice symptoms, the cancer usually has to be in its advanced stages. By then, it is often too late. The avoidance of cigarette smoke and other carcinogenic substances is thus imperative for protection from this fatal disease.