What are Urine Tests?
Urine laboratory tests are commonly used to help healthcare providers diagnose bladder cancer, or to help them rule out bladder cancer as the cause of a patient’s symptoms.1,2
Visiting a primary care doctor for blood in urine
A visit to a primary healthcare provider is often a first step in the process of diagnosing bladder cancer. Some patients visit their healthcare providers because they have symptoms such as visible blood in the urine or other urinary symptoms.
Urine lab tests to rule out bladder cancer
If the healthcare provider thinks that bladder cancer may be the cause of the symptoms, the patient may be asked to provide a urine sample for analysis in the laboratory. Several types of urine lab tests may be used to help make a diagnosis of bladder cancer, including:
- Urinalysis testing
- Urine cytology testing
- Urine culture testing
- Urine tests for tumor markers
Urinalysis testing for blood in urine
Urinalysis can be used to test a patient’s urine sample for the presence of blood in the urine.1-3 The medical term for the symptom of blood in the urine is hematuria. Many patients diagnosed with bladder cancer have the symptom of blood in the urine that is easily visible, but in some patients the amount of blood is so small that it is not visible to the naked eye. Urinalysis can detect very small amounts of blood in the urine, which can sometimes help to diagnose bladder cancer at an earlier stage, if bladder cancer is present. Urinalysis can also be used to check the levels of other substances, such as sugar, protein, and white blood cells, in a patient’s urine.
Urine cytology tests to detect cancer cells
In a urine cytology test, a sample of the patient’s urine is analyzed under a microscope.1,2 This test can reveal the presence of cancer cells or cells that are pre-cancerous, meaning that they are more likely to become cancer cells later. However, this test is not enough to provide a definite diagnosis on its own—it is possible for cancer cells to be present in the bladder even if no cancer cells are detected in the urine sample.
Urine cytology tests after a cystoscopy
Urine cytology tests can also be used after a procedure called cystoscopy, in which a sterile liquid is injected into the bladder to allow the bladder to expand so it can be adequately examined. When the liquid is removed from the bladder it may be analyzed with cytology testing to check for the presence of cancer or pre-cancer cells.
Urine culture testing to check for UTIs
Urine culture testing can be used to check for urinary tract infections.1 The symptoms of bladder cancers and urinary tract infections can be quite similar, so it is important for healthcare providers check for both infection and cancer if either could be the cause. To carry out this test, the urine sample is left in a dish in the laboratory for several days, which allows any bacteria that may be contained in the urine to grow.
Urine tests for tumor markers
A relatively new type of diagnostic technology for bladder cancer are urine tests for substances called tumor markers.3 It is possible for these tests to detect substances in the urine that may be linked to the presence of bladder cancer cells, but like urine cytology test, they are not perfectly reliable. These new tests include:
- Tests that can detect bladder tumor-associated antigen (BTA)
- A test that can detect the genetic changes that are common in bladder cancer cells
- A test that can detect substances often found on cancer cells, called mucin and carcinoembryonic antigen (CEA)
- A test that can detect a protein (called NMP22) that is often elevated in patients with bladder cancer
Next steps after urine lab tests
Depending on the results of the patient’s physical examination and urine laboratory tests, healthcare providers may need to carry out further testing to help make a diagnosis.1,2 The tests can also be used in patients who have already been diagnosed with bladder cancer to help gather more information about the cancer and develop the patient’s treatment plan.
Other tests for bladder cancer
Other types of tests for bladder cancer include:
- Examination under anesthesia
- Cystoscopy and fluorescence cystoscopy
- Transurethral resection of bladder tumor (TURBT)
- Imaging tests, including pyelogram, CT/CAT scan, MRI, x-rays, and ultrasound