What're the risk factors for lung cancer?
A total of 90% of lung cancer cases are related to smoking. The risk of lung cancer is 30 times greater in smokers than in nonsmokers. This correlates with the total exposure to cigarettes (packs smoked per day times the number of years of smoking, referred to as pack-years). One in seven people who smoke at least two packs per day will die of lung cancer.
Cigar and pipe smoke doubles the risk of developing lung cancer. Between 5,000 to 10,000 Americans develop lung cancer each year from secondhand smoke.
Exposure to air pollution, radiation and industrial chemicals, arsenic, nickel, chromium and asbestos increase the risk of lung cancer. Asbestos alone increases the risk of getting lung cancer four times. The combination of asbestos and smoking increase the risk 90 times. Asbestos exposure is also associated with mesothelioma, a type of cancer that starts in the lining of the chest. There is some evidence that women who smoke have a greater risk than men who smoke of developing the disease.
Tobacco smoking - Smoking is by far the most important risk factor for lung cancer. At the beginning of the 20th century, lung cancer was rare. The introduction of manufactured cigarettes, which made them readily available, changed this. About 87% of lung cancers are thought to result from smoking or passive exposure to tobacco smoke. The N-nitrosamines and polycyclic aromatic hydrocarbons are the two major classes of tobacco-related inhaled carcinogens. N-Nitrosamines are formed during tobacco processing and pyrosynthesis. They originate from nicotine and the alkaloid arecoline. People who breathe the smoke of others (for example, the families of smokers) also have an increased risk of developing the disease. People who quit smoking before developing lung cancer can significantly decrease their risk.
Marijuana - Marijuana contains more tar than cigarettes. Marijuana is also inhaled very deeply and the smoke is held in the lungs for a long time. Marijuana is smoked all the way to the end where tar content is the highest. Many of the cancer-causing substances in tobacco are also found in marijuana. Because marijuana is an illegal substance, it is not possible to control whether it contains fungi, pesticides, and other additives. Medical reports suggest marijuana may cause cancers of the mouth and throat.
Asbestos - Exposure to asbestos is a significant risk factor for a particular type of lung cancer called mesothelioma, which starts in the pleura (or lining) of the lung. Asbestos exists in many natural forms. The silicate fiber has been implicated in carcinogenesis, is chemically inert, and can remain in a person's lungs for a lifetime. Asbestos workers who smoke increase their risk of getting lung cancer by 50-100 times. Besides asbestos, mining industry workers who are exposed to coal products or radioactive substances such as uranium, and workers exposed to chemicals such as arsenic, vinyl chloride, mustard gas, and other carcinogens also have a higher than average risk of contracting lung cancer.
Radon - Radon is a naturally occurring, chemically inert gas that is a decay product of uranium. Radon is an invisible, odorless gas that occurs naturally in the soil. Because radon may be present in some homes, it is a good idea to have a radon test performed on a home before purchasing it. Radon test kits are available at many hardware stores. Once a radon problem has been corrected in the home, the hazard from radon is gone. Radon exposure also can occur in the workplace, especially to those individuals who work in mines. Radon decays to products that emit heavy ionizing alpha particles. Radon exposure increases the risk of developing lung cancer as much as 10 times, and lung cancer caused by radon exposure is usually the small-cell type.
Lung diseases - Some lung diseases, like tuberculosis, increase the likelihood of developing lung cancer, especially in regions of the lung that are already scarred. A person who already has been treated for lung cancer is more likely to develop a second lung tumor than someone who has never had lung cancer. Inflammation and scar tissue are sometimes produced in the lung by diseases such as silicosis and berylliosis, which are caused by inhalation of certain minerals; tuberculosis; and certain types of pneumonia.
Radiation therapy to the lung - People who have had radiation therapy to the chest for cancer are at higher risk for lung cancer, particularly if they smoke. The most typical patients are those treated for Hodgkin disease or women who receive radiation to the chest after a mastectomy for breast cancer. Women who receive radiation therapy to the breast after a lumpectomy do not have a higher than expected risk of lung cancer. But if they smoke, their chance of lung cancer goes up markedly.
Work-related exposure to substances - Substances associated with lung cancer include uranium, arsenic, vinyl chloride, nickel chromates, coal products, mustard gas, chloromethyl ethers, gasoline, diesel exhaust and high levels of talc dust.
Diet - Diet may also be a risk factor for lung cancer. Some reports have indicated that a diet low in fruits and vegetables may increase the chances of getting cancer if you are exposed to tobacco smoke. Evidence is growing that fruits and vegetables may protect you against lung cancer.
Genetic factors - Although the exact cause of lung cancer is not known, people with a family history of lung cancer appear to have a slightly higher risk of contracting the disease. The risk of lung cancer appears to be increased in individuals with chronic obstructive pulmonary disease, even when the degree of cigarette consumption is taken into account. Increased metabolism of the antihypertensive drug debrisoquine has been associated with an increased risk of lung cancer.
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.