Renal transitional cell carcinoma (urothelial carcinoma)

The kidneys are two bean-shaped organs on either side of the waist—closer to the back of the body than the front—and responsible for filtering waste from the blood and producing urine, which collects in the renal pelvis, an area toward the middle of each kidney.

From the renal pelvis, urine is carried out of the kidneys via a long tube (called a ureter) to the bladder, then exits the body through the urethra. The lining of the renal pelvis is made up of transitional cells that are able to bend and stretch without breaking.

When cancer grows in these pliable cells, it’s called transitional cell carcinoma (TCC). When this type of cancer develops in the renal pelvis and/or the ureter, it’s called renal transitional cell carcinoma. According to the American Cancer Society, about 5 percent to 10 percent of all kidney cancers are TCCs, also referred to as urothelial carcinomas.

Causes and risk factors

Although risk factors may increase the chance of developing cancer, they don’t guarantee someone will get it.

Renal transitional cell carcinoma risk factors include:

• Past or current history of bladder cancer 
• Smoking
• Excessive use of pain medications, including phenacetin
• Exposure to chemicals and dyes used to make items such as leather, plastic, rubber and textile goods.

Symptoms

Although renal transitional cell carcinoma may not cause early symptoms, as the cancerous tumor grows, patients may experience the following:

• Bloody urine
• Persistent back pain
• Extreme fatigue
• Unexplainable weight loss
• Recurrent or painful urination

Diagnosis

To diagnose renal transitional cell cancer:

• The doctor gathers the patient’s personal health history and conducts a physical exam in order to assess overall health.
• A urine specimen is collected and evaluated in a urinalysis.
• A ureteroscopy may be performed. During this procedure, a thin instrument with a lighted lens, called a ureteroscope, is used to examine the renal pelvis for suspicious areas. If abnormalities are found, a small biopsy (a collection of cells from the area) may be taken to check for cancer.

Other tests may include:

• Urine cytology, which is used to detect cancerous cells and other abnormalities in urine
• Computed tomography (CT) scan, to produce 3D images of the body’s internal structures
• Ultrasound, which uses sound waves to produce echoes that form a sonogram, or picture, of the body’s internal tissues
• Magnetic resonance imaging (MRI) scan, to supply detailed images of the inside of the body using magnets.

Additional tests may be conducted to determine whether the cancer has spread beyond the renal pelvis.

Cancer only located in the kidney is described as localized. If it’s spread to surrounding tissues, lymph nodes and blood vessels, it’s described as regional. Metastatic renal transitional cell carcinoma has spread to other areas of the body.

If the patient has been treated successfully but the cancer returns, it’s described as recurrent.

TCC is given a stage 0 through 4, based on the cancer’s size and location.

• Stage 0: Abnormal cells are found inside the renal pelvis and/or ureter, and may be stage 0a or 0is. Stage 0a describes narrow, lengthy growths that extend from inside these areas, while stage 0is describes a growth that is flat in appearance.
• Stage 1: Cancer has grown from inside the renal pelvis and/or ureter to the local connective tissue.
• Stage 2: Cancer has extended to the local muscle layer.
• Stage 3: Cancer has spread to the kidney itself or to the fat that surrounds the renal pelvis or ureter.
• Stage 4: The cancer has metastasized to one or more areas, including nearby organs, distant areas of the body, lymph nodes and the fat layer surrounding the kidney.

Treatment

The most common form of treatment for renal transitional cell carcinoma is surgery, including procedures such as:

• Nephroureterectomy, which involves removal of the affected kidney, ureter and bladder cuff
• Segmental resection of the ureter, involving removal of the cancerous portion of the ureter, along with a healthy margin of surrounding tissue, followed by reattachment of the remaining ends

Other types of treatment are still being studied and used in clinical trials. These include:

• Fulguration, removal of cancerous tissue with electricity, using a tool that has a wired loop on one end
• Segmental resection of the renal pelvis, removal of the affected area of renal pelvis and not the entire kidney
• Laser surgery, meant to destroy cancer cells
• Regional chemotherapy and biologic therapy, involving chemotherapy drugs to stop cancer cells from multiplying and biologic therapy to attack cancer through the body’s immune system (“regional” refers to the placing of the drugs directly into the renal pelvis or the ureter)

Patients may also consider asking their care team whether a clinical trial may be the right approach for them.