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Table of Contents What is screening?
General Information About Lung Cancer
Lung Cancer Screening
Risks of Lung Cancer Screening
Get More Information From NCI
Changes to This Summary (02/17/2006)
Questions or Comments About This Summary
About PDQ
What is screening?
Screening is looking for cancer before a person has any symptoms. This can help find
cancer at an early stage. When abnormal tissue or cancer is found early, it may
be easier to treat. By the time symptoms appear, cancer may have begun
to spread.
Scientists are trying to better understand which
people are more likely to get certain types of cancer. They also study the things
we do and the things around us to see if they cause cancer. This
information helps doctors recommend who should be screened for cancer, which
screening tests should be used, and how often the tests should be done.
It is important to remember that your doctor does not necessarily
think you have cancer if he or she suggests a screening test. Screening
tests are given when you have no cancer symptoms.
If a screening test result is abnormal, you may need to have more tests done to find out if you have cancer. These are called diagnostic tests.
Refer to the following PDQ summaries for information about prevention, diagnosis, and treatment of lung cancer:
Back to Top General Information About Lung Cancer
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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 inside the
chest. The lungs bring oxygen into the body when breathing in and send carbon
dioxide out of the body when breathing out. Each lung has sections called lobes. The left lung has two
lobes. The right lung, which is
slightly larger, has three. 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 involved in lung cancer. Small tubes called bronchioles and tiny air sacs called alveoli make up the inside of the
lungs.
There are two types of lung cancer: small
cell lung cancer and non-small cell
lung cancer.
Lung cancer is the leading cause of cancer death in the United States.
Lung cancer is the leading cause of cancer death and the second
most common nonskin cancer in the United States.
Tobacco smoking is the most important risk factor for lung cancer.
Anything that increases a person's chance of developing a disease
is called a risk factor. The main cause of lung cancer is tobacco use, including smoking cigarettes, cigars, or pipes, now or in the past.
There are other risk factors for lung cancer, but even when taken together, their effect on lung cancer is very small compared to the effect of tobacco smoking. These include the following:
- Being exposed to second-hand smoke.
- Being exposed to asbestos, arsenic, chromium, nickel, or other workplace agents.
- Being exposed to radon, which can be found in the home as well as in the workplace.
Back to Top Lung Cancer Screening
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Tests are used to screen for different types of cancer.
Some screening tests are used because they have been shown to be helpful both in finding cancers early and decreasing the chance of dying from these cancers. Other tests are used because they have been shown to find cancer in some people; however, it has not been proven in clinical trials that use of these tests will decrease the risk of dying from cancer.
Scientists study screening tests to find those with the fewest risks and most benefits. Cancer screening trials also are meant to show whether early detection (finding cancer before it causes symptoms) decreases a person's chance of dying from the disease. For some types of cancer, finding and treating the disease at an early stage may result in a better chance of recovery.
Clinical trials that study cancer screening methods are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Cancer.gov Web site.
Two
tests have commonly been used to screen for lung cancer.
It has not yet been shown that screening for lung cancer with either of the following tests decreases the chance of dying from lung cancer:
Chest x-ray
A chest x-ray is an x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
Sputum cytology
Sputum cytology is a procedure in which a sample of sputum (mucus that is brought up from the lungs by coughing) is viewed under a microscope to check for cancer cells.
New tests are being studied in clinical trials.
Spiral CT scan
Spiral CT scan is a procedure that makes a series of very detailed pictures of areas inside the body using an x-ray machine that scans the body in a spiral path. The pictures are made by a computer linked to the x-ray machine. This procedure is also called a helical CT scan.
Screening clinical trials are taking place in many parts of the country.
Information about NCI's lung screening trial can be found at the National Lung Screening Trial (NLST) Web site. Information about other clinical trials is available from the
NCI Cancer.gov Web
site.
Back to Top Risks of Lung Cancer Screening
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Screening tests have risks.
Decisions about screening tests can be difficult. Not all screening tests are helpful and most have risks. Before having any screening test, you may
want to discuss the test with your doctor. It is important to know the risks of
the test and whether it has been proven to reduce the risk of dying from cancer.
The risks of lung cancer screening tests include the following:
Finding lung cancer may not improve health or help you live
longer.
Screening
may not improve your health or help you live longer if you have advanced lung cancer or if it has already spread to
other places in your body.
Some cancers never cause symptoms or become life-threatening, but if found by a screening
test, the cancer may be treated. It is not known if treatment of these cancers would help you live longer than if no treatment were given, and treatments for cancer may have serious side effects.
False-negative test results can occur.
Screening test results may appear to be normal even though lung cancer is
present. A person who receives a false-negative test result (one that
shows there is no cancer when there really is) may delay seeking medical care even if there are symptoms.
False-positive test results can occur.
Screening test results may appear to be abnormal even though no
cancer is present. A false-positive test result (one that shows there is cancer when there really isn't) can cause anxiety and is usually followed by more tests (such as biopsy), which also have risks. A biopsy to diagnose lung cancer can cause part of the lung to collapse. Sometimes surgery is needed to reinflate the lung.
Chest x-rays expose the chest to radiation.
Radiation exposure
from chest x-rays may increase the
risk of developing certain cancers, such as breast cancer.
Your doctor can advise you about your risk for lung cancer and your need for screening tests.
Back to Top Get More Information From NCI
Call 1-800-4-CANCER
For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. The call is free and a trained Cancer Information Specialist is available to answer your questions.
Chat online
The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 9:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.
Write to us
For more information from the NCI, please write to this address:
- NCI Public Inquiries Office
- Suite 3036A
- 6116 Executive Boulevard, MSC8322
- Bethesda, MD 20892-8322
Search the NCI Web site
The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our “Best Bets” search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results.
There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.
Find Publications
The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.
Back to Top Changes to This Summary (02/17/2006)
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Changes were made to this summary to match those made to the health professional version.
Back to Top Questions or Comments About This Summary
If you have questions or comments about this summary, please send them to Cancer.gov through the Web site’s Contact Form. We can respond only to email messages written in English.
Back to Top About PDQ
PDQ is a comprehensive cancer database available on NCI's Web site.
PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.
PDQ contains cancer information summaries.
The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.
The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.
Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.
PDQ also contains information on clinical trials.
A clinical trial is a study to answer a scientific question, such as whether a method of finding cancer earlier can help people to live longer. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients and those who are at risk for cancer. During screening clinical trials, information is collected about the effects of a new screening method and how well it works. If a clinical trial shows that a new method is better than one currently being used, the new method may become "standard." People who are at high risk for a certain type of cancer may want to think about taking part in a clinical trial.
Listings of clinical trials are included in PDQ and are available online at NCI's Web site. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.
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