Tests for Kidney Cancer

Kidney cancer might be found because of signs or symptoms a person is having, or it might be found because of lab tests or imaging tests a person is getting for another reason. The actual diagnosis of kidney cancer is made by looking at a sample of kidney cells in the lab or sometimes by how the kidney looks on an imaging test. If you think you have possible signs or symptoms of kidney cancer, see your doctor.

Medical history and physical exam

If you have any signs or symptoms that suggest you might have kidney cancer, your doctor will want to take your complete medical history to check for risk factors and to learn more about your symptoms.

A physical exam can provide information about signs of kidney cancer and other health problems. For example, the doctor may be able to feel an abnormal mass (lump) when he or she examines your abdomen (belly).

If symptoms or the results of the physical exam suggest you might have kidney cancer, more tests will probably be done. These might include lab tests,imaging tests, or biopsies of the kidney.

Blood tests

Lab tests cannot show for sure if a person has kidney cancer, but they can sometimes give the first hint that there may be a kidney problem. If cancer has already been diagnosed, they are also done to get a sense of a person’s overall health and to help tell if the cancer might have spread to other areas. They also can help show if a person is healthy enough to have an operation.

Special tests are done on a urine sample to look for small amounts of blood and other substances not seen with the naked eye. About half of all patients with renal cell cancer will have blood in their urine. If the patient has transitional cell carcinoma (in the renal pelvis, the ureter, or the bladder), sometimes a special test of the urine sample (called urine cytology) will show actual cancer cells in the urine.

Complete blood count (CBC): This is a test that measures the number of different cells in the blood. This test result is often abnormal in people with kidney cancer. Anemia (having too few red blood cells) is very common. Less often, a person may have too many red blood cells (called polycythemia) because the kidney cancer cells make a hormone (erythropoietin) that causes the bone marrow to make more red blood cells. Blood counts are also important to make sure a person is healthy enough for surgery.

Blood chemistry tests: These tests are usually done in people who might have kidney cancer, because the cancer can affect the levels of certain chemicals in the blood. For example, high levels of liver enzymes are sometimes found. High blood calcium levels may be found which might lead to more imaging tests. Blood chemistry tests also measure kidney function, which is especially important if certain imaging tests or if surgery is planned.

Urinalysis (urine testing)

This test of your urine may be done if your doctor suspects a kidney problem.

Imaging tests to look for kidney cancer

Imaging tests use x-rays, magnetic fields, sound waves, or radioactive substances to create pictures of the inside of your body. Imaging tests are done for a number of reasons, such as:

  • To look at suspicious areas that might be cancer
  • To learn how far cancer might have spread
  • To help determine if treatment is working
  • To look for possible signs of cancer coming back after treatment

Unlike most other cancers, doctors can often diagnose kidney cancer with fair certainty based on imaging tests without doing a biopsy (removing a sample of the tumor). Some patients, however, may need a biopsy.

Computed tomography (CT) scan

The CT scan uses x-rays to make detailed cross-sectional images of your body. It can provide precise information about the size, shape, and location of a tumor. It is also useful in checking to see if a cancer has spread to nearby lymph nodes or to organs and tissues outside the kidney.

CT-guided needle biopsy: If a kidney biopsy is needed, this test can also be used to guide a biopsy needle into the mass (lump) to get a sample to check for cancer.

When a CT is done to look at the kidneys, an IV (intravenous) contrast dye is often needed to make certain areas stand out better on the scan. This CT contrast can damage the kidneys. This happens more often in patients whose kidneys are not working well in the first place. Because of this, your kidney function will be checked with a blood test before you get IV contrast.

Magnetic resonance imaging (MRI) scan

MRI scans may be done when a person can’t have the CT contrast dye because they have an allergy to it or they don’t have good kidney function. MRI scans may also be done if there’s a chance that the cancer has grown into major blood vessels in the abdomen (like the inferior vena cava), because they provide a better picture of blood vessels than CT scans. Finally, they may be used to look at abnormal areas in the brain and spinal cord that might be due to cancer spread.

Ultrasound

Ultrasound can help find a kidney mass and show if it is solid or filled with fluid (kidney tumors are more likely to be solid). Different ultrasound patterns can also help doctors tell the difference between some types of benign and malignant kidney tumors.

If a kidney biopsy is needed, this test can also be used to guide a biopsy needle into the mass to take a sample.

Angiography

Angiography is an x-ray test that looks at blood vessels. In traditional angiography, a contrast dye is injected into the renal artery, and the dye outlines the blood vessels. X-rays are taken to identify and map the blood vessels that feed a kidney tumor.

This test can help in planning surgery for some patients. Angiography can also help diagnose renal cancers since the blood vessels usually have a special appearance with this test.

Nowadays, angiography is done as a part of a CT or MRI scan , instead of as a separate x-ray test. This means less contrast dye is used, which is helpful since the dye can damage kidney function.

Chest x-ray

An x-ray may be done after kidney cancer has been diagnosed to see if cancer has spread to the lungs. More often though, a CT chest is done because it can see abnormal areas better. 

Bone scan

A bone scan can help show if a cancer has spread to your bones. A small amount of low-level radioactive material is injected into the blood and collects mainly in abnormal areas of bone. It might be done if there is reason to think the cancer might have spread to the bones such as bone pain or blood test results showing an increased calcium level.

Kidney biopsy

Unlike with most other types of cancer, biopsies are sometimes not needed to diagnose kidney tumors. In certain cases, imaging tests can provide enough information for a surgeon to decide if an operation is needed. The diagnosis is then confirmed when part of the kidney that was removed is looked at in the lab.

biopsy might be done to get a small sample of tissue from an area that may be cancer when the imaging tests are not clear enough to permit surgery. Biopsy may also be done to confirm cancer if a person might not be treated with surgery, such as with small tumors that will be watched and not treated, or when other treatments are being considered.

Fine needle aspiration (FNA) and needle core biopsy are 2 types of kidney biopsies that may be done.

In cases where the doctors think kidney cancer might have spread to other sites, they may take a biopsy of the metastatic site instead of the kidney.

Biopsy results

The biopsy samples are sent to a lab, where they are looked at by a pathologist, a doctor who specializes in diagnosing diseases with lab tests. If kidney cancer is found, an important feature that is evaluated is the grade, specifically called the Fuhrman grade.

The Fuhrman grade is found by looking at kidney cancer cells in the lab. Many doctors use it to describe how quickly the cancer is likely to grow and spread. The grade is based on how closely the cancer cells look like those of normal kidney cells. Renal cell cancers are usually graded on a scale of 1 through 4. Grade 1 renal cell cancers have cells that look a lot like normal kidney cells. These cancers usually grow and spread slowly and tend to have a good prognosis (outlook). At the other extreme, grade 4 renal cell cancer looks quite different from normal kidney cells. These cancers tend to have a worse prognosis.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Atkins MB. UpToDate. Clinical manifestations, evaluation, and staging of renal cell carcinoma. This topic last updated: Nov 13, 2018. Accessed at https://www.uptodate.com/contents/clinical-manifestations-evaluation-and-staging-of-renal-cell-carcinoma on November 22, 2019.

Correa AF, Lane BR, Rini BI, Uzzo RG. Ch 66 - Cancer of the kidney. In: DeVita VT, Hellman S, Rosenberg SA, eds. Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.

McNamara MA, Zhang T, Harrison MR, George DJ. Ch 79 - Cancer of the kidney. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier: 2020.

National Cancer Institute. Physician Data Query (PDQ). Renal Cell Cancer Treatment – Patient Version. 2019. https://www.cancer.gov/types/kidney/patient/kidney-treatment pdq. Updated November 8, 2019. Accessed on November 22, 2019.

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Kidney Cancer. V.2.2020. Accessed at: www.nccn.org on November 22, 2019.

References

Atkins MB. UpToDate. Clinical manifestations, evaluation, and staging of renal cell carcinoma. This topic last updated: Nov 13, 2018. Accessed at https://www.uptodate.com/contents/clinical-manifestations-evaluation-and-staging-of-renal-cell-carcinoma on November 22, 2019.

Correa AF, Lane BR, Rini BI, Uzzo RG. Ch 66 - Cancer of the kidney. In: DeVita VT, Hellman S, Rosenberg SA, eds. Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2019.

McNamara MA, Zhang T, Harrison MR, George DJ. Ch 79 - Cancer of the kidney. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa: Elsevier: 2020.

National Cancer Institute. Physician Data Query (PDQ). Renal Cell Cancer Treatment – Patient Version. 2019. https://www.cancer.gov/types/kidney/patient/kidney-treatment pdq. Updated November 8, 2019. Accessed on November 22, 2019.

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Kidney Cancer. V.2.2020. Accessed at: www.nccn.org on November 22, 2019.

Last Revised: February 1, 2020

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