Risk Factors
A risk factor is a characteristic, behavior, or condition that raises the possibility of developing a disease. Here are some known risk factors for developing lung cancer:
Smoking
Smoking any type of tobacco product is the biggest risk factor for lung cancer, and is responsible for over 80% of all diagnoses. Your risk increases with the amount you smoke per day and the length of time you've been smoking. The good news is that you can greatly lower this risk by quitting as early as possible. After you quit smoking, the damaged tissues in your lungs will gradually begin to heal. In addition, screening for patients at high risk for developing lung cancer is available. High-risk patients include those aged 50-80 years, who are current or former smokers, and patients with 30 pack-years of smoking. A "pack year" is the number of packs of cigarettes smoked per day multiplied by the number of years smoked, e.g. 1 pack per day for 30 years = 30 pack years; 2 packs per day for 15 years = 30 pack years; etc. Former smokers must have stopped smoking within the past 15 years.
Secondhand Smoke
Breathing in the smoke of other peoples' cigarettes can raise your chance of getting lung cancer. Someone who lives with a smoker has a much higher-than-average risk for developing lung cancer.
Exposure
Exposure to certain carcinogenic toxins such as radiation, asbestos, radon, cadmium, arsenic, soot, and tar can increase your risk for lung cancer. Radon is an odorless gas that occurs naturally. Radon detection kits are inexpensive and available at most home-improvement stores.
Family History
Close relatives of a person who has had lung cancer are more likely to develop the disease in some cases. Some people inherit certain genetic mutations that increase the likelihood of developing lung cancer.
Air Pollution
People who live in major cities with lots of traffic and air pollution may be at a slightly higher risk for lung cancer.
Radiation Therapy
People who have received prior radiation therapy to the chest are at higher risk for lung cancer. Women treated with adjuvant radiation therapy after a lumpectomy or mastectomy (removal of entire breast) for breast cancer and patients treated for Hodgkin disease are among those at higher risk, particularly if the treatment started before 1990.
Lung Disease
Lung diseases such as tuberculosis and other severe infections can damage the tissue in your lungs and potentially increase your risk for lung cancer or prevent early detection due to scarring.
