Diagnosis of kidney cancer
Diagnosing kidney cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and may do a physical exam. Based on this information, your doctor will refer you to a specialist or order tests to check for kidney cancer or other health problems.
The process of diagnosis may seem long and frustrating. It’s normal to worry, but try to remember that other health conditions can cause similar symptoms as kidney cancer. It’s important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of kidney cancer.
The following tests are commonly used to rule out or diagnose kidney cancer. Many of the same tests used to diagnose cancer are used to find out the stage, which is how far the cancer has progressed. Your doctor may also order other tests to check your general health and to help plan your treatment.
Your health history is a record of your symptoms, risk factors and all the medical events and problems you have had in the past. In taking a health history, your doctor will ask questions about a personal history of:
- symptoms that suggest kidney cancer
- high blood pressure
- being overweight or obese
Your doctor may also ask about a family history of:
- kidney cancer
- risk factors for kidney cancer
- other cancers
A physical exam allows your doctor to look for any signs of kidney cancer. During a physical exam, your doctor may feel your abdomen, back and side to see if there is a lump in the kidney area.
Find out more about physical exam.
Urinalysis is a test that measures substances in urine. These substances include electrolytes, hormones and other waste products of metabolismmetabolismThe chemical processes in the body that create and use energy. It includes breaking down food and transforming it into energy, eliminating wastes and toxins, breathing, circulating blood and regulating temperature..
Urinalysis can be used to check for blood in the urine, which you might not be able to see. If there is blood in the urine, it means that there is bleeding into or within the kidneys or urinary tract. This bleeding can be a sign of kidney cancer.
Find out more about urinalysis.
A urine cytology test looks for abnormal cells in the urine. Your doctor may order this test if urinalysis finds blood in your urine.
Find out more about cell and tissue studies, including cytology.
Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are functioning and can help find abnormalities. Blood chemistry tests used to diagnose kidney cancer include the following.
Blood urea nitrogen (BUN) and creatinine may be measured to check how well the kidneys are working. Higher levels of these substances may mean that the kidneys are not functioning well, which may be because of cancer.
Glomerular filtration rate (GFR) is another test used to check how well the kidneys are working. It measures how much blood is passing through the glomeruli, which are the tiny filters in the kidney that remove waste from the blood. The creatinine level is combined with several other factors, such as your age, sex, height, weight and ethnicity, to estimate the GFR. Low levels of GFR may be a sign that you have chronic kidney disease. Very high levels are a sign that your kidneys are failing, which needs to be treated immediately.
Calcium and phosphorus levels may be high if you have kidney disease or if cancer has spread to the bone.
Alkaline phosphatase levels may be high if kidney cancer has spread to the bones or liver.
Liver function tests may be done to see if there is a problem with the liver. Sometimes with kidney cancer, liver function tests may be abnormal when there are no tumours found in the liver (called Stauffer syndrome). Liver function tests return to normal after the kidney tumour is removed with surgery.
Find out more about blood chemistry tests.
A CBC measures the number and quality of white blood cells, red blood cells and platelets. A CBC is often abnormal in people who have kidney cancer.
A CBC is done to check for anemia (low levels of red blood cells) from long-term, or chronic, bleeding. Anemia is common in people with kidney cancer. Red blood cells may look paler than normal when looked at under a microscope (called hypochromic anemia).
Kidney cancer can make a hormone called erythropoietin. This hormone causes the bone marrow to make too many red blood cells. A CBC will tell your doctor if you have a higher than normal number of red blood cells (called polycythemia).
A CBC is also used to make sure that a person is healthy enough for surgery.
Find out more about complete blood count (CBC).
A computed tomography (CT) scan uses special x-ray equipment to make 3-D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures.
A CT scan is the imaging test most commonly used to diagnose kidney cancer. It is used to get information about the size, shape and location of the tumour. It is also used to find out if the tumour has spread to the lymph nodes, blood vessels or other organs.
CT scan may also be used to guide the doctor to the tumour during a biopsy.
Find out more about CT scan.
Ultrasound uses high-frequency sound waves to make images of structures in the body. It is used to look for any changes to the kidney. It can show the difference between a kidney cyst, which has fluid inside, and a solid tumour.
Ultrasound may also be used to guide the doctor to the tumour during a biopsy.
Find out more about ultrasound.
Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3-D pictures.
Sometimes an MRI is used to check if cancer has spread to the kidney’s major blood vessels or to other organs.
MRI is not used if a CT scan and other tests clearly show the kidney tumour and how far it has spread. It may not be used in all cancer treatment centres in Canada.
Find out more about MRI.
During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. The report from the lab will confirm whether or not cancer cells are present in the sample.
A kidney, or renal, biopsy is not usually done because imaging tests, such as CT scan and ultrasound, usually confirm the diagnosis of a kidney tumour.
In some cases, a biopsy may be used to confirm the diagnosis of cancer and find out the type of tumour. It may be done before treatment is started if the tumour is smaller than 3 cm and the person is not well enough to have surgery.
During a kidney biopsy, you lie on your stomach so doctors can easily reach the kidney during the procedure. A local anesthetic is used to freeze the area. In some cases, you may be given a general anesthetic. Using ultrasound or CT scan as a guide, the doctor pushes a needle through the back and into the kidney. The doctor will remove several samples from the kidney and the tumour.
Find out more about biopsy.
An angiography is a procedure used to create an image of blood vessels in the kidneys. Doctors use angiography to help them map the tumour’s blood vessels and plan the surgery.
Find out more about angiography.
An x-ray uses small doses of radiation to make an image of the body’s structures on film. A chest x-ray is used to see if the kidney cancer has spread to the lungs.
Find out more about x-ray.
A bone scan uses bone-seeking radioactive materials (called radiopharmaceuticals) and a computer to create a picture of the bones. It is used to see if kidney cancer has spread to the bone. It is usually used if blood chemistry test results, such as increased alkaline phosphatase or calcium levels, suggest that kidney cancer has spread to the bone.
Find out more about bone scan.