How is bladder cancer diagnosed?
Bladder cancer is usually found because of specific symptoms a patient is presenting or during urine testing for other reasons. A diagnosis has always to be confirmed by exams and tests, which can also help to determine the stage of the cancer.
Medical History and Physical Exam
In case of signs or symptoms suggesting bladder cancer, your doctor will want to capture your complete medical history to check for risk factors and learn more about your symptoms.
A physical examination provides further information about possible signs of bladder cancer. The urologist might examine the rectum to feel for potential bladder cancer and estimate size and spread of the tumour. In case of abnormal results, further tests are necessary, like urine analysis and cystoscopy.
Cystoscopy is usually performed in any case of suspected bladder cancer. Here, a cystoscope – a slim tube with a fibre-optic device or small camera on the end – is moved through the urethra into the bladder. Sterile saline is the instilled to expand the bladder, allowing the urologist to examine the inner lining of the bladder. This method can be performed in a doctor’s office with the help of local anaesthesia to numb the urethra. If an abnormal area is seen it will be directly biopsied and the sample sent to a lab for closer examination.
Fluorescent dyes might be used to make cancer cells easier visible under blue light during cystoscopy.
For this test, urine sample will be microscopically examined for free cancer cells. Those are easily missed, however. This test is simple but not very precise and a negative result does not necessarily mean that no cancer is present.
In order to rule out a simple bladder infection, which can cause similar symptoms as bladder cancer, a urine culture is usually set up. Here, a sample of the urine is set under optimal bacterial growth condition to look if bacteria have been present in the urine, indication a mostly harmless infection.
Urine Tumour Marker Tests
Bladder cancer cells produce different characteristic substances (like proteins). Those can be detected in the urine. The specificity of those tests is highly debated and they can currently not replace a cystoscopy.
A biopsy is the removal of a small sample of body tissue to see if it is cancer. The tissue that is removed is sent to the lab, where it is looked at by a pathologist. If bladder cancer is suspected, a biopsy is needed to confirm the diagnosis.
Bladder biopsy samples are most often obtained during cystoscopy. A biopsy can show whether cancer is present and what type of bladder cancer it is. If bladder cancer is found, two important characteristics are its invasiveness and grade.
Invasiveness: The biopsy can show how deeply the cancer has invaded the bladder wall, which is very important in deciding treatment. If the cancer is found in the inner layer of cells without growing into the deeper layers, yet, it is called non-invasive. If the cancer has already grown into the deeper layers of the bladder, it is called invasive. Invasive cancers are more likely to spread and are harder to treat.
You may also see a bladder cancer described as superficial or non-muscle invasive. These terms include both non-invasive tumours as well as any invasive tumours that have not grown into the main muscle layer of the bladder.
Grade: Bladder cancers are also assigned a grade, based on how they look under the microscope.
- Low-grade cancers look more like normal bladder tissue. They are also called well-differentiated cancers. Patients with these cancers usually have a good prognosis (outlook).
- High-grade cancers look less like normal tissue. These cancers may also be called poorly differentiated or undifferentiated. High-grade cancers are more likely to grow into the bladder wall and to spread outside the bladder. These cancers can be harder to treat.
- Some pathologists use a grading system from G1 to G3, with higher numbers indiucating poorer differentiation.
People with bladder cancer may develop more cancers in other areas of the bladder or in the urinary system. For this reason, during the biopsy the doctor may take tissue samples from several different areas of the bladder lining.
Biopsies to look for Cancer Spread
If imaging tests suggest the cancer might have spread outside of the bladder, a biopsy is the only way to be sure. In some cases, biopsy samples of suspicious areas are obtained during surgery to remove the bladder cancer.
Another way to get a biopsy sample is to use a thin, hollow needle to take a small piece of tissue from the abnormal area. This is known as a needle biopsy, and by using it the doctor can take samples without an operation. Needle biopsies are sometimes done using a CT scan or ultrasound to help guide the biopsy needle into the abnormal area.
Imaging tests use x-rays, magnetic fields, ultrasound, or radioactive substances to generate pictures of the inside of your body. If you have bladder cancer, the doctor may order some of these tests to see if the cancer has spread to tissues near the bladder, nearby lymph nodes, or to distant organs. If an imaging test shows enlarged lymph nodes or other possible signs of cancer spread, some type of biopsy might be needed to confirm the findings.
An intravenous pyelogram (IVP), also called an intravenous urogram (IVU), is an x-ray of the urinary system taken after injecting a special dye into a vein. This dye is removed from the bloodstream by the kidneys and then passes into the ureters and bladder. The dye outlines these organs on x-rays and helps show urinary tract tumours.
Some people have allergic reactions to the dye, so it’s important to tell your doctor if you have any allergies or have ever had any reactions to x-ray dyes.
For this test, a catheter is placed through the urethra and up into the bladder or into a ureter. Then a dye is injected through the catheter to make the lining of the bladder, ureters, and kidneys easier to see on x-rays.
This test isn’t used as often as IVP, but it may be done (along with ultrasound of the kidneys) to look for tumours in the urinary tract in people who can’t have an IVP because they are allergic to x-ray dyes.
Computed Tomography (CT) Scan
The CT scan uses x-rays to produce detailed cross-sectional images of your body. A CT scan of the kidney, ureters, and bladder is known as a CT urogram. It can provide detailed information about the size, shape, and position of any tumours in the urinary tract, including the bladder. It may be used instead of an IVP to look at the upper part of the urinary system. It can also help show enlarged lymph nodes that might contain cancer, as well as other organs in the abdomen and pelvis.
Instead of taking one picture, like a standard x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body.
Magnetic Resonance Imaging (MRI) Scan
Like CT scans, MRI scans provide detailed images of soft tissues in the body. The difference is that MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into very detailed images of parts of the body. A contrast material called gadolinium is often injected into a vein before the scan to see details more clearly.
MRI images are particularly useful in finding signs that the cancer has spread outside of the bladder into nearby tissues or lymph nodes. A special MRI of the kidneys, ureters, and bladder, known as an MRI urogram, can be used instead of an IVP to look at the upper part of the urinary system.
Ultrasound (ultrasonography) uses sound waves to create pictures of internal organs. It can be useful in determining the size of a bladder cancer and whether it has spread beyond the bladder to nearby organs or tissues. It can also be used to look at the kidneys.
This is an easy test to have. It uses no radiation, which is why it is often used to look at developing fetuses. For the exam, you simply lie on a table while a transducer is placed on the skin over the part of your body being looked at. Usually, the skin is first lubricated with gel. The transducer gives off sound waves and picks up the echoes as they bounce off organs in the body. The echoes are converted by a computer into a black-and-white image.
Ultrasound-guided needle biopsy: Ultrasound can also be used to guide a biopsy needle into a suspected area of cancer spread in the abdomen or pelvis.