Diagnosis of kidney cancer

Diagnosis is the process of finding out the cause of a health problem. Diagnosing kidney cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and 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 usually used to rule out or diagnose kidney cancer. Many of the same tests used to diagnose cancer are used to find out the stage (how far the cancer has spread). 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 and risks and all the medical events and problems you have had in the past. Your doctor will ask questions about your history of:

• symptoms that suggest kidney cancer
• smoking
• high blood pressure
• overweight and obesity

Your doctor may also ask about a family history of:

• kidney cancer
• risks 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 exams.

Urinalysis is a test that measures substances such as electrolytes, hormones and blood in the urine (pee). If there is blood in the urine, it means that there is bleeding into or within the kidneys or urinary tract.

Find out more about urinalysis.

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are working 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 could mean that the kidneys are not working well, which could be because of cancer.

Glomerular filtration rate (GFR) is another test used to check how well the kidneys are working. It estimates how much blood is passing through the glomeruli, which are the tiny filters in the kidneys that remove waste from the blood. The creatinine level in the blood is measured and is calculated with several other factors, such as your age, sex, height, weight and ethnicity, to determine the GFR. Low GFR means that the kidneys are not filtering the blood very well and could suggest there is a problem with the kidneys.

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.

Find out more about blood chemistry tests.

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check for anemia (low levels of red blood cells) from long-term bleeding. Anemia is very common in people with kidney cancer.

Very rarely, 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.

A CBC is also used to make sure that a person is healthy enough to have surgery.

Find out more about a complete blood count (CBC).

A computed tomography (CT) scan uses special x-ray equipment to make 3D 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.

A CT scan may also help guide the doctor to the tumour during a biopsy.

Find out more about CT scans.

An ultrasound uses high-frequency sound waves to make images of parts of 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.

An ultrasound may also help guide the doctor to the tumour during a biopsy.

Find out more about ultrasounds.

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 3D pictures.

Sometimes an MRI is used to check if cancer has spread to the kidney’s major blood vessels or to other organs.

An MRI is not used if a CT scan and other imaging tests clearly show the kidney tumour and how far it has spread.

Find out more about MRIs.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from a pathologist will show whether or not cancer cells are found in the sample.

A kidney biopsy is not usually done to diagnose kidney cancer. Imaging tests like CT scans and ultrasounds usually confirm the diagnosis.

In some cases, a biopsy may be done to get a small sample of tissue from an area that may be cancer, if the imaging tests were not clear enough to make a diagnosis. It may be done before treatment is started if the tumour is small and the person is not well enough to have surgery.

Find out more about biopsies.

An angiography uses images to see how the blood flows through the blood vessels in the kidneys to help plan treatment.

Find out more about angiography.

An x-ray uses small doses of radiation to make an image of parts of the body on film. A chest x-ray is used to see if the kidney cancer has spread to the lungs.

Find out more about x-rays.

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 tests, such as increased alkaline phosphatase or calcium levels, suggest that kidney cancer has spread to the bone.

Find out more about bone scans.

To make the decisions that are right for you, ask your healthcare team questions about a diagnosis.