Kidney (Renal Cell) Cancer

The kidneys are an important organ that are responsible for filtering blood and removing excess water, salt and waste. Kidney cancer begins in the tissues of the kidney and can spread to other body parts. It is one of the 10 most common cancers in the U.S., accounting for about 4 to 5 percent of all cancers. It’s about twice as common in men as in women.

Types & Stages

There are two main types of kidney cancer: renal cell carcinoma (RCC), also known as renal cortical tumors, and upper tract urothelial tumors (transitional cell tumors). 

• Renal cortical tumors account for more than 9 out of every 10 kidney tumors. They start in the main part of your kidney, which has structures called renal tubules. There are many kinds of renal cortical tumors. They don’t all behave the same. Your treatment depends on the type of tumor you have. Most types of kidney tumors are malignant (cancer). Some tumors are benign (not cancer) and are most often removed through surgery and don’t come back. Examples of benign tumors include renal cysts, oncocytomas and angiomyolipomas.
   
• Upper tract urothelial tumors starts in your renal pelvis. That’s where urine collects before it goes into the ureter, a tube that connects the kidney to the bladder. Urothelial tumors affect the lining of the urinary tract, including the renal pelvis, ureters, bladder and urethra. Urothelial (transitional cell) tumors are different from renal cortical tumors. They come from a different type of cell and behave more like bladder cancer.

Surgery for these cancers is a little different. To fight urothelial tumors that have spread, we use treatments developed for bladder cancer. 

Because of these differences, it’s important to have a correct diagnosis of renal cortical or upper tract urothelial tumors.

Signs & Symptoms

Most people with renal cell carcinoma don’t have obvious symptoms, and it isn’t found until the cancer has advanced. When symptoms begin to occur the patient will experience:

• Blood in the urine (hematuria)
• Pain in the sides of mid-back
• Mass in the abdomen or side of back
• In men, swelling around left testicle

Diagnosis

Your doctor may order certain tests that can help in diagnosing and assessing cancer. These may include:

• Urinalysis: A sample of your urine is tested to see if it contains blood.
   
• Blood tests: These tests count the number of each of the different kinds of blood cells, as well as look at different electrolytes in your body. A blood test can show if there are too few red blood cells (anemia), or if your kidney function is impaired (by looking at the creatinine).
   
• CT scan compiles a series of detailed X-ray images taken from different angles. A dye may be introduced into your bloodstream so the kidneys show up more clearly.
   
• Magnetic resonance imaging (MRI) uses a magnet and radio waves to take a series of detailed images of the kidneys and other adjacent tissues.
   
• Ultrasound uses high-energy sound waves that reflect off internal tissues, and the resulting echoes collectively form a visual image called a sonogram.
   
• Cystoscopy is when we place a small tube with a lens into your urethra (thin tube that carries urine from the bladder). This test lets us see your urethra and bladder.
   
• Ureteroscopy is when we pass a narrow, lighted tube through your urethra and into the bladder, a ureter and the renal pelvis.
   
• Renal mass biopsy is a procedure in which a thin needle is inserted into the tumor, and a small sample of your tissue is removed. A pathologist will look at the tissue under a microscope to see if there are any cancer cells. Because biopsies for kidney cancer aren’t always completely reliable, your doctor might not recommend this test.

Treatment

Treatment of kidney cancer will be determined by the stage and grade of cancer, and your overall health. It can include: 

• Active surveillance (monitoring) would be the approach for a small, non-aggressive tumor.
   
• Medical therapies include targeted therapies, immunotherapy and occasionally chemotherapy.
   
• Renal mass ablation also called percutaneous cryosurgery, generally reserved for frail patients who can’t undergo surgery. Cryotherapy uses extreme cold to destroy the tumor through a needle inserted into the tumor, either through the skin (percutaneously) or during laparoscopy. In the latter a long, thin tube with a tiny video camera on the end is inserted into your abdomen through a small incision.
   
• Robotic radical nephrectomy (surgical removal of the kidney), which is used in cases where the patient has multiple tumors or the tumor is large and located centrally within the kidney. Removing the kidney is a safe option if the other kidney is functioning normally.
   
• Robotic partial nephrectomy, in which the entire kidney isn’t removed, is a common treatment that is sometimes preferred for patients whose kidneys don’t work well, because it allows both kidneys to keep working. During this treatment the cancer is destroyed by burning it.

Causes & Risk Factors

Factors that may increase kidney cancer risk include:

• Smoking and the longer a person smokes, the higher the risk.
   
• Obesity. In general, the more overweight a person is, the higher the risk.
   
• High blood pressure, also called hypertension, has been linked to an increased risk of kidney cancer.
   
• Family history. People who have family members with kidney cancer may have an increased risk of developing cancer themselves.
   
• Radiation therapy. Women who have been treated with radiation for cancer of their reproductive organs may have a slightly increased risk of developing kidney cancer.
   
• Long-term dialysis treatment is the process of cleaning your blood by passing it through a special machine. Dialysis is used when a person’s kidneys aren’t functioning properly.
   
• Certain hazardous substances. Exposure to arsenic, asbestos, cadmium, some herbicides, benzene or trichloroethylene (TCE), which are present in certain occupational settings, can increase the risk of kidney cancer.
   
• Certain hereditary conditions such as von Hippel-Lindau disease, Birt-Hogg-Dube syndrome, hereditary papillary renal cell carcinoma, hereditary renal oncocytoma and hereditary leiomyoma renal cell carcinoma have been linked to kidney tumors.

Screening

Currently, there is no kidney cancer screening method that is reliable enough to be recommended for routine use among the general public. This can make early detection a challenge. For patients who have risk factors such as certain inherited conditions, your doctor will typically recommend regular imaging tests to look for kidney tumors. These tests may include:

• Intravenous pyelogram (IVP), which involves injecting a contrast dye into your bloodstream, after which a series of X-rays are taken as the dye moves through the kidneys, ureters and bladder.
   
• CT scan, which compiles a series of detailed X-ray images taken from different angles.
   
• Magnetic resonance imaging (MRI), which uses magnet and radio waves to take a series of detailed images of the kidneys and other adjacent tissues.
   
• Ultrasound, which uses high-energy sound waves that reflect off internal tissues, and the resulting echoes collectively form a visual image called a sonogram.