- About Screening
- Screening Tests
- Screening Risks
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.
See the following PDQ treatment summaries for information about diagnosis and treatment of bladder and other urothelial cancers.
- Bladder Cancer
- Transitional Cell Cancer of the Renal Pelvis and Ureter
Bladder and other urothelial cancers are diseases in which malignant (cancer) cells form in the urothelium.
The bladder is a hollow organ in the lower part of the abdomen. It is shaped like a small balloon and has a muscle wall that allows it to get larger or smaller. The bladder holds urine until it is passed out of the body. Urine is the liquid waste that is made by the kidneys as they clean the blood. The urine passes from the two kidneys into the bladder through two tubes called ureters. When the bladder is emptied during urination, the urine goes from the bladder to the outside of the body through another tube called the urethra.
The urothelium is a layer of tissue that lines the urethra, bladder, ureters, prostate, and renal pelvis. Cancer that begins in the urothelium of the bladder is much more common than cancer that begins in the urothelium of the urethra, ureters, prostate, or renal pelvis. Because it is the most common form of urothelial cancer, bladder cancer is the focus of this summary.
There are 3 types of cancer that begin in the urothelial cells of the bladder. These cancers are named for the type of cells that become malignant (cancerous):
- Transitional cell carcinoma: Cancer that begins in cells in the innermost layer of the bladder urothelium. These cells are able to stretch when the bladder is full and shrink when it is emptied. Most bladder cancers begin in the transitional cells.
- Squamous cell carcinoma: Cancer that forms in squamous cells, which are thin, flat cells that may form in the bladder urothelium after long-term infection or irritation.
- Adenocarcinoma: Cancer that begins in glandular (secretory) cells. Glandular cells in the bladder urothelium make substances such as mucus.
Most newly diagnosed bladder cancers occur in people 60 years and older.
In the United States, bladder cancer occurs more often in men than in women, and more often in whites than in blacks. As the U.S. population has gotten older, the number of people diagnosed with bladder cancer has increased, but the number of deaths from bladder cancer has decreased. This is true for men and women of all races over the last 30 years. However, blacks and women with bladder cancer are more likely to die from the disease than white men with bladder cancer are.
Smoking, gender, and diet can affect the risk of developing bladder cancer.
Anything that increases your 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 bladder cancer include:
- Using tobacco, especially smoking cigarettes.
- Being 60 years or older, male, or white.
- Being exposed to certain substances, such as soot from coal, or chemicals used to make rubber, certain dyes, or textiles.
- Working as a dry cleaner or in places where paper, rope, twine, or clothing is made.
- Taking A. fangchi, a Chinese herb.
- Drinking water that has high levels of arsenic.
- Having a history of many bladder infections.
- Long-term use of urinary catheters.
- Past treatment with certain anticancer drugs or radiation therapy to the pelvis.
- Having a kidney transplant.
- Having an inherited disorder called hereditary nonpolyposis colon cancer (HNPCC; Lynch syndrome).
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 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, finding and treating the disease at an early stage may result in a better chance of recovery.
There is no standard or routine screening test for bladder cancer.
Screening for bladder cancer is under study and there are screening clinical trials taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site.
Two tests may be used to screen for bladder cancer in patients who have had bladder cancer in the past:Cystoscopy
Cystoscopy is a procedure to look inside the bladder and urethra to check for abnormal areas. A cystoscope (a thin, lighted tube) is inserted through the urethra into the bladder. Tissue samples may be taken for biopsy.
Urine cytology is the examination of urine under a microscope to check for abnormal cells.
Hematuria tests may also be used to screen for bladder cancer.
Hematuria (red blood cells in the urine) may be caused by cancer or by other conditions. A hematuria test is used to check for blood in a sample of urine by viewing it under a microscope or using a special test strip. The test may be repeated over time.
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.
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 cystoscopy or other invasive procedures), which also have risks. False-positive results often occur with hematuria testing; blood in the urine is usually caused by conditions other than cancer.
False-negative test results can occur.
Screening test results may appear to be normal even though bladder 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.
Your doctor can advise you about your risk for bladder cancer and your need for screening tests.