Dr. E. Zigiriadis

MD, FC Cardio (SA)

Lung cancer Prevention

  • What is prevention?

    Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.

    To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

    Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.

    Different ways to prevent cancer are being studied, including:

    - Changing lifestyle or eating habits.

    - Avoiding things known to cause cancer.

    - Taking medicines to treat a precancerous condition or to keep cancer from starting.

  • Lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung.

    The lungs are a pair of cone-shaped breathing organs in the chest. The lungs bring oxygen into the body as you breathe in. They release carbon dioxide, a waste product of the body’s cells, as you breathe out. 
    Each lung has sections called lobes. The left lung has two lobes. The right lung is slightly larger, and has three lobes. A thin membrane called the pleura surrounds the lungs. Two tubes called bronchi lead from the trachea (windpipe) to the right and left lungs. 
    The bronchi are sometimes also involved in lung cancer. Tiny air sacs called alveoli and small tubes called bronchioles make up the inside of the lungs.
    Anatomy of the respiratory system, showing the trachea and both lungs and their lobes and airways. Lymph nodes and the diaphragm are also shown. Oxygen is inhaled into the lungs and passes through the thin membranes of the alveoli and into the bloodstream (see inset).

    There are two types of lung cancer: small cell lung cancer and non-small cell lung cancer.

    See the following PDQ summaries for more information about lung cancer:

    - Lung Cancer Screening

    - Non-Small Cell Lung Cancer Treatment

    - Small Cell Lung Cancer Treatment

  • Lung cancer is the leading cause of cancer death in both men and women.

    More people die from lung cancer than from any other type of cancer. Lung cancer is the second most common cancer in the United States, after skin cancer.
    Key Points for This Section
    1) Avoiding risk factors and increasing protective factors may help prevent lung cancer.

    2) The following risk factors may increase the risk of lung cancer:
     - Cigarette, cigar, and pipe smoking
    - Secondhand smoke
    - Environmental risk factors
    - Alcohol use
    - Beta carotene supplements in heavy smokers

    3) The following protective factors may decrease the risk of lung cancer:

    - Not smoking
    - Quitting smoking
    - Eating more fruits and vegetables
    - Exercising

    Taking vitamin E supplements does not affect the risk of lung cancer.
    Cancer prevention clinical trials are used to study ways to prevent cancer.
    New ways to prevent lung cancer are being studied in clinical trials.

  • Avoiding risk factors and increasing protective factors may help prevent lung cancer.

    Avoiding cancer risk factors such as smoking, being overweight, and lack of exercise may help prevent certain cancers. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

  • The following risk factors may increase the risk of lung cancer:

    1) Cigarette, cigar, and pipe smoking

    Tobacco smoking is the most important risk factor for lung cancer. Cigarette, cigar, and pipe smoking all increase the risk of lung cancer.

    2) Secondhand smoke

    Being exposed to secondhand tobacco smoke is also a risk factor for lung cancer. Secondhand smoke is the smoke that comes from a burning cigarette or other tobacco product, or that is exhaled by smokers. People who inhale secondhand smoke are exposed to the same cancer -causing agents as smokers, although in smaller amounts. Inhaling secondhand smoke is called involuntary or passive smoking.

    3) Environmental risk factors

    Radon exposure: Radon is a radioactive gas that comes from the breakdown of uranium in rocks and soil. It seeps up through the ground, and leaks into the air or water supply. Radon can enter homes through cracks in floors, walls, or the foundation, and levels of radon can build up in the home.

    Studies show that high levels of radon gas inside homes and other buildings increase the number of new cases of lung cancer and the number of deaths caused by lung cancer. In nonsmokers, about 30% of deaths caused by lung cancer have been linked to being exposed to radon.

    4) Air pollution
    Some studies have shown a link between air pollution and an increased risk of lung cancer.
    5) Other environmental factors
    There are other environmental risk factors for lung cancer. These include:

    - Asbestos
    - Arsenic
    - Chromium
    - Nickel
    - Tar and soot

    These substances can cause lung cancer in people who are exposed to them in the workplace and have never smoked. The risk of lung cancer is higher in people who are exposed and also smoke. Being exposed to these substances is much less likely to cause lung cancer than cigarette smoking is.
    6) Alcohol use
    Some studies have shown that drinking large amounts of alcohol is linked to an increased risk of lung cancer.
    7) Beta carotene supplements in heavy smokers
    Taking beta carotene supplements (pills) can increase the risk of lung cancer in smokers who smoke one or more packs a day. The risk is higher in smokers who also drink one or more alcoholic drinks every day.

  • The following protective factors may decrease the risk of lung cancer:

    1) Not smoking
    The best way to prevent lung cancer is to not smoke.
    2) Quitting smoking
    Smokers can decrease their risk of lung cancer by quitting. In smokers who have been treated for lung cancer, quitting smoking lowers the risk of new lung cancers. Counseling, the use of nicotine replacement products (such as gum, patches, sprays, lozenges, or inhalers), and antidepressanttherapy have helped smokers quit for good.

    In a person who has quit smoking, the chance of preventing lung cancer depends on how many years and how much the person smoked and the length of time since quitting.

    3) Eating more fruits and vegetables
    Studies show that eating a lot of fruits or vegetables may help lower the risk of lung cancer.
    4) Exercising
    Study results have been mixed about whether exercising or being physically active lowers the risk of lung cancer. Some studies have shown that people who are physically active have a lower risk of lung cancer even if they smoke.
    5) Taking vitamin E supplements does not affect the risk of lung cancer.
    6) Cancer prevention clinical trials are used to study ways to prevent cancer.
    Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.

    The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.

    7) New ways to prevent lung cancer are being studied in clinical trials.
    Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI Web site. Check NCI’s PDQ Cancer Clinical Trials Registry for prevention trials for non-small cell lung cancer and small cell lung cancer that are now accepting patients. These include trials for quitting smoking.