What causes lung cancer?
Cigarette smoking is the most significant cause of lung cancer. Cigarette smoke contains more than 4000 chemicals, many of which have been identified as causing cancer. These substances are known as carcinogens (which means "cancer-causing agents"), and it is these carcinogens that cause the actual damage to the cells in the lungs. A cell that is damaged may become cancerous over a period of time. An estimated 80% of lung cancers result from smoking, due to the hundreds
of known carcinogens, such as benzene, present in cigarette smoke. The length of time that a person continues to smoke as well as the amount smoked increases their chances of contracting lung cancer. However if someone stops smoking then these chances steadily decrease as the damage to their lungs is repaired.
Passive smoking, whereby exhaled smoke is taken up by other people, has recently been identified as a much larger cause of lung cancer in non-smokers than previously believed. A person living with a smoker has twice the risk of lung cancer of someone not regularly exposed to smoke. Prolonged exposure to the smoke of others, in for example, the working environment, also increases risk, and this increase may apply not only to non-smokers, but to smokers as well.
Asbestos exposure increases the risk of lung cancer by 9 times. A combination of asbestos exposure and cigarette smoking compounds the risk by as much as 50 times. Asbestos is a family of fibrous minerals that occur in underground deposits. Asbestos is used in home insulation, fire-proofing, tiles for floors and ceilings, automobile brake linings, and other products. It is believed that irritating asbestos fibers can cause cancer. The risk of lung cancer is higher in workers who are exposed to asbestos on the job (miners, construction workers, auto mechanics who work with brakes), as well as in people who live or work in buildings where asbestos-containing building products are deteriorating. In general, asbestos exposure tends to increase the risk of squamous cell carcinoma or adenocarcinoma, especially in people who also smoke cigarettes.
Radon gas, which occurs naturally in rocks and soil in certain areas, may cause lung damage and may eventually result in lung cancer if it seeps into your home. High levels of a radioactive gas (radon) that cannot be seen or smelled pose a risk for lung cancer. This gas is produced by the breakdown of uranium, and does not present any problem outdoors. In the basements of some houses that are built over soil containing natural uranium deposits, however, radon may accumulate to dangerous levels. Having one's house inspected for the presence of radon gas when buying or renting is a good idea. Other forms of environmental pollution (e.g., auto exhaust fumes) may also slightly increase the risk of lung cancer.
Lung diseases such as tuberculosis (TB) and chronic obstructive pulmonary disease (COPD) also create a risk for lung cancer. A person with COPD has a 4-6 times greater risk of lung cancer even when the effect of cigarette smoking is excluded.
Oncogenes are genes which is believed make people more susceptible to cancer. Proto-oncogenes are believed to turn in to oncogenes when exposed to particular carcinogens. Viruses are suspected to cause cancer in humans, as this link has already been proven in animals.
More information on lung cancer
What is lung cancer? - Lung cancer is a malignant tumour of the lungs. Lung cancer is the cancer that originates in the tissues of the lungs. Lung cancer is the leading cause of cancer deaths.
What types of lung cancer are there? - The lungs are made up of several kinds of cells that perform different functions. The type of lung cancer depends on which cell type is affected.
What is small cell lung cancer? - Small cell lung cancer is a type of lung cancer in which the cells look like oats. Small cell lung cancer is almost always caused by smoking.
What is non-small cell lung cancer? - Non-small cell lung cancers include squamous cell carcinoma, adenocarcinoma, large cell carcinoma, adenosquamous carcinoma, and undifferentiated carcinoma.
What causes lung cancer? - Cigarette smoking is the most significant cause of lung cancer. Asbestos exposure increases the risk of lung cancer. Lung diseases create a risk for lung cancer.
What're the risk factors for lung cancer? - Risk factors for lung cancer include tobacco smoking, marijuana, asbestos, radon, lung diseases, radiation therapy, work-related exposure to substances.
What're the signs and symptoms of lung cancer? - Lung cancer may cause a number of symptoms. The primary symptoms of lung cancer are cough, shortness of breath, hoarseness, blood in the sputum, and pain.
How is lung cancer diagnosed? - Diagnosis of lung cancer may be made by physical examination, chest X rays, bronchoscopy, or percutaneous needle biopsy. Lung biopsy is the most definitive diagnostic tool for cancer.
What're the lung cancer stages? - Lung cancer is staged according to its location, size, cell type, and spread. Knowing the stage of lung cancer helps the doctor set the treatment plan.
What're the treatments for lung cancer? - The treatment of lung cancer depends on the type and stage of the disease and includes surgery, radiation therapy, and chemotherapy.
What's the treatment for small cell lung cancer? - At limited stage treatments for small cell lung cancer include various combinations of chemotherapy, radiation.
What's the treatment for non-small cell lung cancer? - Surgery is the primary treatment for all non¨Csmall cell lung cancers. Radiation therapy may be administered.
Treatment for non-small cell lung cancer by stage - Stage III non-small cell lung cancer are treated with radiation and sometimes with surgery, chemotherapy, or combinations of each.
What's the prognosis of lung cancer survival rate? - The prognosis of lung cancer depends on the type of lung cancer, its stage, and the overall health of the patient.
How to prevent lung cancer? - Prevention of lung cancer includes quitting smoking and avoiding exposure to potentially cancer-causing substances in the work environment.
Asbestos lung cancer - The most serious hazard of exposure to asbestos is cancer. Lung cancer causes the largest number of deaths related to asbestos exposure.