Kidney Cancer (Renal Cancer) - Types, Symptoms, Causes And Treatment

Kidney cancer represents about 3 percent of all cancers in the United States. Each year, more than 28,000 Americans are diagnosed with kidney cancer. The risk of kidney cancer increases with age. It is more common in men than in women. Kidney cancer is a type of cancer that starts in the cells in the kidney.The two most common types of kidney cancer are renal cell carcinoma (RCC) and urothelial cell carcinoma (UCC) of the renal pelvis. These names reflect the type of cell from which the cancer developed.

 Types of kidney cancer

The different types of kidney cancer (such as RCC and UCC) develop in different ways, meaning that the diseases have different outlooks (or prognosis), and need to be staged and treated in different ways. RCC is responsible for approximately 80% of primary renal cancers, and UCC accounts the majority of the remainder.

• Renal cell carcinoma (RCC) — This is the most common form of kidney cancer in adults and accounts for 85% of all kidney cancers. Renal cell carcinoma usually develops as a single tumor in one kidney, but it can affect both kidneys. Renal cell carcinoma begins in the cells that line the small tubes that are part of the nephrons within the kidneys. (Renal is the Latin word for kidney, and the term "carcinoma" refers to cancer that begins in the cells that line or cover an organ.)
• Transitional cell carcinoma — Transitional cell carcinoma accounts for 6% to 7% of all kidney cancers. This cancer usually begins in the area where the ureter connects to the main part of the kidney. This area is called the renal pelvis. Transitional cell carcinoma also can occur in the ureters or bladder.
• Renal sarcoma — This is the least common form of kidney cancer, accounting for only 1% of kidney cancer cases. It begins in the connective tissues of the kidneys and, if not treated, can spread to nearby organs and bones.
• Wilms’ tumor — This is the most common type of kidney cancer in children. It accounts for about 5% of kidney cancers.

Kidney cancer, which most often occurs in men 50 to 70 years old, rarely produces symptoms in its early stages. Eventually, though, a tumor in one of the kidneys may trigger one or more of the following:

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• blood in the urine (most common symptom)
• persistent pain in the back, just below the ribs
• a lump in the abdomen
• general symptoms such as persistent fatigue, unexplained weight loss, recurrent fevers, high blood pressure, swelling in the ankles

Being aware of these signs can help patients catch their condition and begin treatment as soon as possible.
Options for treating kidney cancer include surgery to remove the kidney, chemotherapy, radiation therapy, hormone therapy, and biological or immunotherapy. Sometimes, when the disease is tightly confined, treatment may involve removing only the affected portion of the kidney. This procedure is called a partial nephrectomy or nephron-sparing surgery and can help preserve the function of the involved kidney

Symptoms of kidney cancer

Kidney cancer may not produce any noticeable symptoms in its early stages. However, as the tumor grows, symptoms may begin to appear. For that reason, kidney cancer is often not diagnosed until it has begun to spread.

Symptoms of kidney cancer can include:

• Blood in the urine (a condition called hematuria)
• A lump or mass in the kidney area
• Tiredness
• Loss of appetite and/or weight
• Low-grade fever
• Pain in the side
• Bone pain
• A general sense of not feeling well
• High blood pressure
• Anemia (a condition that results from not having enough red blood cells)

Causes of kidney cancer

The exact cause of kidney cancer is not known, but several risk factors have been identified. A risk factor is something -- such as a characteristic or behaviour -- that increases your chance of developing a disease. Risk factors for kidney cancer include:

• Smoking — Smokers are at greater risk for kidney cancer. In addition, the longer a person smokes, the higher the risk.
• Radiation — Women who have been treated with radiation for cancer of the reproductive organs may have a slightly increased risk for developing kidney cancer.
• Gene changes (mutations) — Genes contain instructions for a cell’s function. Changes in certain genes can increase the risk of developing kidney cancer.
• Family history — People who have family members with kidney cancer may have an increased risk for developing the cancer themselves.
• History of tuberous sclerosis — Tuberous sclerosis is a disease that causes seizures and mental retardation, as well as the formation of tumors in many different organs.
• Long-term dialysis treatment — Dialysis is the process of cleaning the blood by passing it through a special machine. Dialysis is used when a person’s kidneys are not functioning properly.
• Von Hippel-Lindau (VHL) disease — People with this inherited disorder are at greater risk for developing kidney cancer. This disorder causes non-cancerous tumors in the blood vessels, typically in the eyes and brain. 

Stages of kidney cancer

Most cancers are grouped by stage, a description of the cancer that aids in planning treatment. The stage of a cancer is based on the location and size of the tumor; the involvement, if any, of the lymph nodes; and the degree that the cancer has spread, if at all, to other tissue and organs. The doctor uses information from various tests -- such as CT, MRI and biopsy -- to determine the stage of the cancer.

• Stage I — The tumor is confined to the renal capsule (the fibrous tissue surrounding the kidney) and is smaller than ¾ inch in length or larger than ¾ inch but has not spread to lymph nodes or other tissue. (Lymph nodes are small "filters" that trap germs and cancer cells, and store infection-fighting cells.)
• Stage II — The tumor has spread to the surrounding fat and adrenal gland (small gland that sits on top of the kidney.)
• Stage III — The tumor has spread to the major blood vessels – the renal vein and inferior vena cava -- and regional lymph nodes.
• Stage IV — The cancer has spread to nearby organs or lymph nodes, or to distant organs.

Tumors are also graded, which is a way of rating a tumor based on how abnormal its cells look. Tumor grading can also tell the doctor how fast the tumor is likely to grow. Tumors whose cells do not look like normal cells and divide rapidly are called high-grade tumors. High-grade tumors tend to grow and spread more quickly than low-grade tumors.

 Treatment of kidney cancer

Treatment depends on the type of cancer, the stage and grade of the tumor, and the patient's age and overall health.
Surgery is the most common treatment for kidney cancer. Several surgical options may be considered, including:

• Simple nephrectomy — The surgeon removes just the kidney.
• Partial nephrectomy — The surgeon removes just the part of the kidney that contains the tumor.
• Radical nephrectomy — The surgeon removes the whole kidney, along with the adrenal gland and some of the tissue around the kidney. Some lymph nodes in the area also may be removed.

When one kidney is removed, the remaining kidney usually is able to perform the work of both kidneys.
A procedure called arterial embolization is sometimes used before surgery. During this procedure, a small catheter (tube) is inserted into an artery in the groin and moved through the blood vessel until it reaches the kidney. A special material is injected through the catheter to block the main blood vessel of the kidney (renal artery). This prevents the cancer cells from getting oxygen or other substances they need to grow.
Surgery is the treatment of choice for most stages of kidney cancer. Chemotherapy or biological therapy may be used for stage IV cancer, when the cancer has spread beyond the kidney. Chemotherapy, or chemo, uses medicines to kill or stop the growth of cancer cells. Biological therapy uses the body’s own immune system to fight cancer.
Hormone therapy is another treatment option. This treatment uses hormones to try and control the growth of cancer cells.
Some people with kidney cancer participate in clinical trials. Clinical trials are research programs conducted with patients to evaluate new medical treatments, drugs or devices. Clinical trials also are being conducted on new chemotherapy drugs and on new ways to use biological therapy for patients with kidney cancer.


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