Kidney Cancer

Kidney cancer at a glance

• Kidney cancer occurs when abnormal cells grow out of control and form a cancerous tumor in the kidneys—the organ that help the body process urine.
• Many kidney cancers do not have symptoms at first, and may be diagnosed during an imaging scan of the abdominal area.
• Most kidney cancers are diagnosed while the tumor is still small.
• Although kidney cancer is a serious disease, treatments are available to halt or slow its growth.

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What is kidney cancer?

Kidney cancer is the uncontrolled growth of abnormal cells in the kidneys. The kidneys are two bean-shaped organs, each about the size of a fist. They lie in your mid abdomen on each side of your spine. The kidneys are part of the urinary tract. Their main job is to remove waste products from the blood and remove them by making urine.

About 73,000 people will be diagnosed with kidney cancer in 2019. It is more common in men than woman. The average age at diagnosis is 64.

About 9 out of 10 adults who develop kidney cancer are diagnosed with renal cell carcinoma. There are a few other types of kidney cancer, although they are less common. Young children sometimes have a kidney cancer called a Wilms’ tumor.

Many kidney cancers are found through imaging scans of the abdomen, such as computerized tomography (CT) and ultrasound. Most kidney tumors (85 percent) are found early before they spread. These cancers are easier to treat.

Kidney cancer staging

After doctors have diagnosed kidney cancer, they identify whether cancer has spread, and by how much. Using these findings, doctors assign cancer a stage. Kidney cancer stages include:

• Stage I. Only in the kidney and is 2 3/4 inches (7 centimeters) or smaller.
• Stage II. Only in the kidney, but is larger than 7 centimeters.
• Stage III. Has spread beyond the kidney. It may be in a lymph node, a blood vessel or the fatty tissue around the kidney.
• Stage IV. Has spread significantly outside the kidney. It may be in multiple lymph nodes or other parts of the body, such as the lungs, bones or liver.

Causes of kidney cancer

Doctors don’t know what causes kidney cancer. Like other cancers, kidney cancer occurs when cells grow abnormally. These cells form a tumor or mass within the kidney. Some cancer cells can spread to other parts of the body far from the kidneys, which is called a metastatic cancer.

Factors that may increase the risk of kidney cancer include:

• Age. Most people who get kidney cancer are over age 40.
• Smoking. The risk of kidney cancer is twice as high for smokers than for nonsmokers.
• Obesity. This may cause hormone changes that can increase cancer risk.
• Kidney disease or dialysis treatment. Receiving long-term dialysis for chronic kidney failure increases the risk of developing kidney cancer.
• Certain genetic syndromes. People with certain conditions may have higher kidney cancer risk. These conditions include tuberous sclerosis, von Hippel-Lindau disease, familial papillary renal cell carcinoma and Birt-Hogg-Dube syndrome
• Family history. Siblings of people who have had kidney cancer are at greater risk.
• High blood pressure (hypertension).
• Long-term use of over-the-counter or prescription pain medications.
• Having lymphoma, though the reason for the connection is unknown.
• Exposure to certain chemicals, such as asbestos, benzene, cadmium, and some herbicides and organic solvents.

Some people have these risks and never get kidney cancer. While others may develop kidney cancer even when they don’t have any of these risks.

Symptoms and diagnosis of kidney cancer

Often, early kidney cancer won’t have any symptoms. Symptoms generally do not occur until the tumor is large.

Kidney cancer symptoms can include:

• Urine color changes (pink, red or brown) because of blood in urine
• Pain in the side or back (often just below the ribs) that doesn’t go away
• A bulge or lump in the abdomen or side
• Ongoing fever without a clear cause
• Severe fatigue
• Anemia
• Weight loss
• Loss of appetite
• Swollen ankles or legs.

If kidney cancer spreads to other parts of the body, patients may experience shortness of breath, bone pain or coughing.

Diagnosing kidney cancer

Fortunately, more than 85 percent of kidney cancer cases are diagnosed while the tumor is still small. The tests and procedures physicians use to diagnose kidney cancer include:

• Blood and urine tests.
• Imaging tests. Doctors use a variety of tests to create a picture of the kidney to understand if there is a tumor, its location and size. Physicians may order a computerized tomography (CT) scan, magnetic resonance imaging (MRI), x-rays or ultrasound. Sometimes physicians request a renal arteriogram, which can help study the blood supply to the kidney and tumor.
• Kidney biopsy (tissue sample). Occasionally, doctors take a biopsy from the kidney to examine the cells for the presence of cancer. Usually other tests are sufficient and a biopsy is not needed.

After a doctor diagnoses kidney cancer, he or she will likely order additional tests to determine if the cancer has spread. These tests evaluate for cancer in the lymph nodes, lungs, bones, and other organ systems. These tests help determine the cancer stage.

Treatment of kidney cancer

Treatment options for kidney cancer depend on the type of cancer, the patient’s health and age and the cancer’s stage. Below are some of the treatments physicians will consider.

Surgery

Physicians surgically remove most kidney cancer. The type of surgery a surgeon performs depends on the type of cancer.

• Removing only the tumor from the kidney (also called partial nephrectomy). If a tumor is small, the surgeon may be able to remove only the tumor and a margin of tissue around it. Whenever possible, physicians use this surgery for patients who have only one kidney.
• Removing the kidney and surrounding tissue (radical nephrectomy). This surgery is the most common procedure for kidney cancer. This includes removal of the kidney and tissue around the kidney. Often, nearby lymph nodes are also removed. Surgeons can sometimes perform this procedure with a laparoscope, requiring only small incisions.

Non-surgical treatments

For some cancers, surgery is not an option or may not be necessary. Many smaller tumors can be treated with less invasive options.

In these cases, physicians may recommend other treatments to destroy the cancer or control its growth. These treatments include:

• Freezing cancer cells (cryoablation). A needle inserted into the tumor through the skin contains gas that freezes and destroys cancer cells.
• Heating cancer cells (radiofrequency ablation). A needle inserted into the tumor contains an electrical current that destroys the cancer cells.
• Arterial embolization. An artery leading to the kidney is blocked in order to stop blood flow to the tumor. Sometimes, physicians use this treatment to shrink a tumor before surgery.
• Biological therapy (or immunotherapy). This treatment uses drugs that help the body’s immune system help fight the cancer. Drugs in this category include interferon and aldesleukin (Proleukin). These are generally used when the cancer is spread to other parts of the body.
• Targeted therapy. Targeted therapy blocks the signals kidney cancer cells send out to help them grow. Several different drugs target different pathways. The side effects may include a rash, diarrhea and fatigue.
• Radiation therapy. High-energy beams, such as X-rays, are sent from a machine (such as CyberKnife radiosurgery) into the body. Radiation works to control or stop the growth of cancer cells. Sometimes it is used when the cancer has spread to other parts of the body. This is sometimes less effective for kidney cancer than for other kinds of cancer. For this reason, it is not used very often for kidney cancer.