National Cancer Institute
Last Modified: June 8, 2009
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.
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Neuroblastoma often begins in the nerve tissue of the adrenal glands. There are two adrenal glands, one on top of each kidney, in the back of the upper abdomen. The adrenal glands make important hormones that help control heart rate, blood pressure, blood sugar, and the way the body reacts to stress. Neuroblastoma may also begin in the abdomen, chest, spinal cord, or in nerve tissue near the spine in the neck.
Neuroblastoma most often begins during early childhood, usually in children younger than 5 years of age.
Neuroblastoma is the most common type of cancer in infants. The number of new cases of neuroblastoma is greatest among children under 1 year of age. As children get older, the number of new cases decreases. Neuroblastoma is slightly more common in males than females.
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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.
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 Web site.
There is no standard or routine screening test used to find neuroblastoma. A urine test is sometimes used to check for neuroblastoma, usually when the child is 6 months old. This is a test in which urine is collected for 24 hours to measure the amounts of certain substances. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. A higher than normal amount of homovanillic acid (HMA) and vanillyl mandelic acid (VMA) may be a sign of neuroblastoma.
Studies have shown that screening for neuroblastoma does not decrease the chance of dying from the disease. Almost all neuroblastomas that are found by screening children at 6 months of age are the type that have a good prognosis (chance of recovery).
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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.
When a screening test result leads to the diagnosis and treatment of a disease that may never have caused symptoms or become life-threatening, it is called overdiagnosis. For example, when a urine test result shows a higher than normal amount of homovanillic acid (HMA) or vanillyl mandelic acid (VMA), tests and treatments for neuroblastoma are likely to be done, but may not be needed. At this time, it is not possible to know which neuroblastomas found by a screening test will cause symptoms and which neuroblastomas will not. Diagnostic tests (such as biopsies) and cancer treatments (such as surgery, radiation therapy, and chemotherapy) can have serious risks, including physical and emotional problems.
Screening test results may appear to be normal even though neuroblastoma 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 and procedures, which also have risks.
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