Kidney Cancer

Benign and malignant tumors in kidneys and parts of the urinary tract affect more than 60,000 people in the United States each year.

Any type of growth, including one that’s benign, has the potential to affect how kidneys process and filter salts, waste products, and fluids through urination.

The most common type of kidney cancer is renal cell carcinoma, which affects small tubes in one or both of the bean-shaped kidneys.
When caught early, many forms of kidney and urinary tract cancer respond well to treatment.

Causes and Risk Factors

It’s not clear what causes benign or malignant tumors to develop within kidneys or the urinary tract. What is known, however, is that there are several risk factors that can increase the risk of developing abnormal growths within this area of the body. Smoking, for instance, increases the odds of being affected by renal cell carcinoma. Excess weight may also cause certain hormonal changes that could contribute to the development of growths. Twice as likely to affect men, kidney cancer is also associated with the following risk factors:

Exact causes are not always known

Several risk factors may increase risk

Smoking is linked to renal cell carcinoma

Additional Risk Factors

Kidney cancer is also associated with several additional risk factors. Certain medical conditions, exposures, and long-term treatments may increase the risk of developing abnormal growths in the kidneys or urinary tract.

Long-term use of certain medications may increase the risk of kidney cancer.

Being on long-term dialysis may increase the likelihood of developing abnormal growths.

Exposure to certain herbicides and solvents has been linked to increased risk.

Having advanced kidney disease may increase the risk of developing kidney tumors.

High blood pressure is also associated with kidney cancer risk.

Kidney cancer is twice as likely to affect men.

Signs and Symptoms

Patients in the early stages of kidney cancer may not notice any symptoms. As the tumor develops, it may contribute to a loss of appetite or weight loss for no apparent reason. Some patients may also experience extreme or lingering fatigue, anemia, blood in urine, ankle swelling, or fever.

Larger tumors may produce a noticeable lump.

A lump may appear on the side or abdomen.

Cancer spread may cause shortness of breath.

Bone pain may occur if cancer spreads.

Diagnosing Kidney Cancer

Smaller growths are often benign.

Larger tumors are more likely malignant.

Imaging tests help confirm diagnosis.

Biopsy may sometimes be performed.

Thirty to 40 percent of the time, smaller growths detected in kidneys or the urinary tract are benign. Larger tumors are more likely to be malignant. Diagnosis of a renal mass may involve urine and blood tests, a CT scan or MRI, or an intravenous pyelogram (IVP) performed with a special dye. The blood supply to the tumor may be tested with a renal arteriogram. Kidney cancer does not always require a biopsy to make a diagnosis, although a tissue sample may still be taken.

Treatment Options

Monitoring and Follow-Up

After a growth is discovered, initial treatment by a urologist usually involves follow-up image tests 3-6 months later. If the tumor isn’t changing in size or shape, continued observation may be all that’s necessary unless the growth is causing problems with the passage of urine.

Surgical and Minimally Invasive Treatment

If the tumor is becoming larger or it’s cancerous, treatment may involve removal of the affected kidney, the adrenal gland, and nearby tissue (radical nephrectomy), removal of the kidney only (simple nephrectomy), or percutaneous cryoablation performed with a needle-like probe inserted through the skin. In rare instances, some patients experience spontaneous remission.

Detection and Ongoing Evaluation

In the past, renal cancer was usually first detected when patients started to show clear signs of a problem such as blood in urine or abdominal pain. Today, kidney cancer is often detected with ultrasounds and similar image-based tests. A urology specialist may order such tests if a patient is reporting unusual symptoms that suggest something is going on in the urinary tract or kidneys.