Source: National Cancer Institute Research, www.cancer.gov
Screening is looking for cancer before a person has any symptoms. This can help find cancer at an early stage. When abnormaltissue 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.
The esophagus is the hollow, muscular tube that moves food and
liquid from the throat to the stomach. The wall of the esophagus is made up of several layers of tissue,
including mucous membrane, muscle, and connective tissue. Esophageal cancer
starts in the inside lining of the esophagus and spreads outward through the
other layers as it grows.
The two most common types of esophageal cancer are named for the type of cells that become malignant (cancerous):
See the following PDQ summaries for more information about esophageal cancer:
Men are about three times more likely than women to have esophageal cancer. There are more new cases of esophageal adenocarcinoma each year and fewer new cases of squamous cell carcinoma. Squamous cell carcinoma of the esophagus is found more often in blacks than in whites. The chance of developing esophageal cancer increases with age.
Anything that increases the chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor.
Risk factors for squamous cell esophageal cancer include the following:
Risk factors for esophageal adenocarcinoma include the following:
Some screening tests are used because they have been shown to be helpful both in finding cancers early and in 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, the chance of recovery is better if the disease is found and treated at an early stage.
Screening for esophageal cancer is under study with screening clinical trials taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site.
A procedure to look inside the esophagus to check for abnormal areas. An esophagoscope is inserted through the mouth or nose and down the throat into the esophagus. An esophagoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue samples, which are checked under a microscope for signs of cancer.
The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. Taking biopsy samples from several different areas in the lining of the lower part of the esophagus may detect early Barrett esophagus. This procedure may be used for patients who have risk factors for Barrett esophagus.
A procedure in which cells are brushed from the lining of the esophagus and viewed under a microscope to see if they are abnormal. This may be done during an esophagoscopy.
A procedure in which cells are collected from the lining of the esophagus using a deflated balloon that is swallowed by the patient. The balloon is then inflated and pulled out of the esophagus. Esophageal cells on the balloon are viewed under a microscope to see if they are abnormal.
A procedure in which a dye is sprayed onto the lining of the esophagus during esophagoscopy. Increased staining of certain areas of the lining may be a sign of early Barrett esophagus.
A procedure that uses a special light to view tissue in the lining of the esophagus. The light probe is passed through an endoscope and shines on the lining of the esophagus. The light given off by the cells lining the esophagus is then measured. Malignant tissue gives off less light than normal tissue.
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.
Screening may not improve your health or help you live longer if you have advanced esophageal 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 will help you live longer than if no treatment were given, and treatments for cancer may have serious side effects.
Screening test results may appear to be normal even though esophageal 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.
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.
There are rare but serious side effects that may occur with esophagoscopy and biopsy. These include the following: