What increases my risk for lung cancer?

If you are a smoker or have been exposed to hazards such as second-hand smoke, radon, asbestos, arsenic or diesel exhaust, you may have a higher risk for developing lung cancer.

In many cases, cancers can develop because of a combination of factors. For example, no one doubts that smoking increases the incidence of lung cancer. Almost 90 percent of lung cancers are linked to cigarette smoking. Nevertheless, some smokers appear to be even more susceptible to cancer than others. Some people appear to produce higher levels of the enzyme that makes smoke carcinogenic. Thus, their genetic predisposition, combined with their behavioral choices, contributes to an even greater risk of lung cancer. This effect is a good example of how cancer can be caused by both environmental factors and inherited tendencies.

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Tobacco smoking remains the primary cause of lung cancer, although anyone, including non-smokers, can develop the disease from some combination of genetics, radon or asbestos exposure, air pollution or secondhand smoke. Treatments include surgery, chemotherapy and radiation or a combination of options.

Cancer occurs when cells in the body divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant growths. These growths can invade nearby tissues and then spread to other parts of the body.

Factors that may increase your chance of developing lung cancer include:

  • Smoking
  • Using chewing tobacco
  • Being exposed to second-hand smoke
  • Being exposed to asbestos or radon
  • Having a lung disease, such as tuberculosis
  • Having a family or personal history of lung cancer
  • Being exposed to certain air pollutants
  • Being exposed to coal dust
  • Radiation therapy that was used to treat other cancers

This content originally appeared on the HCA Virginia Physicians blog.

Doctors aren't sure exactly what causes lung cancer, but they do know that the main risk factor is cigarette smoking. Lung cancer is also more common as people get older and if there is lung cancer in the family.

However, people may get lung cancer even without risk factors, just as some people with risk factors may never get lung cancer. For smokers, the best way to reduce the risk of getting lung cancer is by not smoking, which helps at any age. Even if a smoker gets lung cancer, stopping smoking can help with treatment.

Dr. Daniel A. Nader, DO
Pulmonary Disease Specialist

The most common cause of lung cancer is tobacco smoking. More than 70 percent of lung cancer is as a result of tobacco use. There are other causes, which include asbestos exposure, radon gas exposure and other chemicals. Secondhand tobacco smoke exposure is also considered a significant risk.

Eighty-seven percent of all cancers of the lung, trachea (windpipe), and bronchi (large airways) are linked to tobacco use, especially cigarette smoking. Exposure to certain environmental carcinogens (substances that cause cancer) also increases your risk of lung cancer.

Dr. Raja M. Flores, MD
Cardiothoracic Surgeon

Family and patient history are the best ways to assess your risk factor for lung cancer. In this video, Raja Flores, MD, thoracic surgeon at The Mount Sinai Medical Center, explains why it's harder to assess lung cancer risk than other diseases.

The Cancer Exercise Training Institute states that tobacco use is to blame for 85 percent of all lung cancers. Fifteen percent arise mainly from occupational and environmental exposures to radon, asbestos and second-hand smoke. Incidence of lung cancer decreases when smoking is stopped; after about fifteen years the risk is the same as that of non-smokers.
According to the National Cancer Institute ( there are over 7,000 chemicals in cigarettes, 250 of them are harmful and 69 out of the 250 cause cancer. Harmful substances in smoke damage lung cells which is why second hand smoke is harmful to nonsmokers.

Risk factors include: (

  • Tobacco smoke: Tobacco smoke causes most cases of lung cancer. It’s by far the most important risk factor for lung cancer.
  • Radon: Radon damages lung cells, and people exposed to radon are at increased risk of lung cancer. The risk of lung cancer from radon is even higher for smokers.
  • Asbestos and other substances: Exposure to asbestos, arsenic, chromium, nickel, soot, tar and other substances can cause lung cancer. Risk is highest for those with years of exposure. The risk of lung cancer for these substances is even higher for smokers.
  • Air pollution: The risk from air pollution is higher for smokers.
  • Family history of lung cancer: People with a father, mother, brother, or sister who had lung cancer may be at slightly increased risk of disease, even if they don’t smoke.
  • Personal history of lung cancer: People who have had lung cancer are at increased risk of developing a second lung tumor.
  • Age over 65: Most people are older than 65 when diagnosed with lung cancer.

You can minimize your risk of lung cancer by:

  • Eliminating your exposure to second hand smoke.
  • Use a home radon testing kit.
  • If you do smoke you can take advantage of:
  1. A smoking cessation course. Check with your local health system. They may offer a course
  2. Nicotine sprays and gum.
  3. Getting the support of family and friends. They can help if they know this is a goal.
  4. Replace the habit with a healthy one.
  5. Understand what triggers your urge for tobacco and find a healthy distraction.
Dr. Ajay K. Sahajpal, MD
Transplant Surgeon

Having risk factors does not mean that you will develop lung cancer. Some people who get the disease may not have had any known risk factors. However, for every risk factor listed, the risk is much higher for people who smoke.

  • Smoking is by far the leading risk factor for lung cancer. The longer a person has been smoking and the more packs per day smoked, the greater the risk. People who don't smoke but who breathe the smoke of others may also be at a higher risk for lung cancer.
  • Radon is a radioactive gas released by the normal breakdown of uranium in soil and rocks. It is found at higher levels in the soil in some parts of the United States. Radon can't be seen, tasted or smelled. It can build up indoors and create a possible risk for cancer. However, the lung cancer risk from radon is much lower than that from tobacco smoke.
  • People who work with asbestos have a higher risk of getting lung cancer. Those exposed to asbestos have a greater risk of developing mesothelioma.
  • Radioactive ores, such as uranium.
  • Inhaled chemicals or minerals like arsenic, beryllium, cadmium, vinyl chloride, nickel compounds, chromium compounds, coal products, mustard gas and chloromethyl ethers.
  • Diesel exhaust. 
  • People who have had radiation therapy to the chest to treat other cancers are at higher risk for lung cancer, although the actual risk is still quite low. However, women who have radiation to the breast after a lumpectomy for breast cancer do not appear to have a higher risk of lung cancer.
  • People who have had lung cancer have a higher risk of getting another lung cancer. Brothers, sisters and children of people who have had lung cancer have a slightly higher risk themselves, especially if the family member developed cancer at a young age.
  • Air pollution may slightly increase the risk of lung cancer, but the risk is still far less than that caused by smoking.

The main risk factor for lung cancer is smoking, with approximately 90 percent of lung cancers being caused by this behavior. A person’s risk for getting lung cancer increases as the amount they smoke, and how long they smoke, increase. Other risk factors for lung cancer include exposure to secondhand smoke, alcohol consumption, air pollution, work exposure to cancer causing chemicals such as silica and asbestos, and a family history of lung cancer.

Though regular cigarette smokers are at the highest risk, even those who haven't smoked but have spent a significant amount of time around secondhand smoke—the smoke from other people—can also develop lung cancer. In some cases, people can develop lung cancer without either of those factors. In those cases, the cause is unknown.

Lung cancer develops because something damages the lung cell's DNA, the genetic material at the heart of lung cells. Many of these damaged cells die but, very rarely, some gain the ability to multiply rapidly, become resistant to death, and spread throughout the body.

By far, the most common activity that causes this damage is cigarette smoking. The chemicals that exist in all cigarette smoke are absorbed by the cells that line the lung. These chemicals damage the cells causing changes, known as mutations, in the DNA. Usually the mutations simply cause the cell to die, but sometimes the mutations trigger rapid growth and a resistance to death, the hallmarks of cancer. Unfortunately, the chemicals that are present in inhaled smoke are also in exhaled smoke. So regardless of whether you are doing the smoking or you inhale the smoke from someone else's cigarette, known as passive or secondhand smoke, your risk of getting cell damage is increased. Smoking pipes and cigars is also a risk, but not as high a risk as cigarettes because the smoke from cigars and pipes is usually not deeply inhaled.

Other things that can cause damage to the DNA in lung cells and thus result in lung cancer include radon gas, a radioactive gas that very rarely can leak into basements. Asbestos fibers, used for insulation in many industries, can be inhaled into the lung during their use and can also lead to chronic inflammation and a higher chance of developing lung cancer. Finally, some of the mutations are hereditary, meaning you are born with them. This means some that some families have a tendency for their members to develop lung cancer, especially if the family member smokes.

When compared to white Americans, African Americans appear to have a higher incidence of lung cancer, as well as a higher risk of dying from the cancer. Both Asian Americans and Hispanic Americans have a lower incidence and lower risk of dying when compared to Caucasians with lung cancer.

There are many potential reasons for these differences. It's possible that the genetic makeup of these different races might predispose one or another of these ethic groups to have different outcomes. Other possible causes include differences in rates of smoking or access to healthcare and other socioeconomic or environmental factors.

There may very well be a slight increase in risk if you live in the city. Cities tend to have higher levels of air pollution because of the greater population density when compared to rural communities. There is concern that air pollution can be associated with a slightly increased risk of lung cancer over long time periods of up to 20 to 30 years. This risk would be increased when combined with smoking, exposure to smoke and other risk factors for lung cancer.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.