Kidney Cancer

Kidney cancer attacks over 30 thousand people and kills over 12,000 each year in the United States, according to the American Cancer Society (ACS). (Read about "Cancer: What It Is")

The kidneys are a pair of hardworking organs that are part of the urinary system. (Read about "The Urinary System") They clear the waste products out of our blood stream. Located just below the rib cage near the middle of your back, they filter about 200 quarts of blood a day to extract about 2 quarts of waste and extra water. It becomes urine and is stored in your bladder until you go to the bathroom. This whole thing takes place in what are called nephrons, where the blood carrying capillaries intertwine with the urine carrying tubules.

The kidneys also release hormones and regulate a number of chemicals in our blood stream such as:

• active form of vitamin D to help regulate the calcium (Read about "Vitamins & Minerals" "Calcium") in our blood for bone building (Read about "Skeletal System")
• renin which helps regulate blood pressure
• erythropoietin or EPO which helps the bone marrow make red blood cells

The kidneys are crucial to our survival, but we don't need both of them. There are people who are born with one kidney (or who donate one to another person) who live normal and active lives. In the case of kidney cancer, if one kidney has to be removed, the remaining kidney generally is able to perform the work of both kidneys. However, if the remaining kidney is not working well (Read about "End Stage Renal Disease") or if both kidneys are removed, dialysis is needed to clean the blood.

Several types of cancer can start in the kidney. Three types of kidney cancer are considered the most common:

• Renal cell carcinoma (RCC) - Renal cell carcinoma is the most common kidney cancer in adults, and accounts for the vast majority of kidney cancers overall. NCI says this type is sometimes called renal adenocarcinoma or hypernephroma.
• Transitional cell cancer of the renal pelvis and ureter (TCC) - The renal pelvis is the area at the center of the kidney. Urine collects there and is then sent, via the ureter, to the bladder. The renal pelvis and ureters are lined with what are called transitional cells. These cells can change shape and stretch. TCC starts in these cells.
• Wilms' tumor - Although kidney cancer is far more common in adults, it can strike children. Wilms' tumor is the most common kidney cancer in children. (Read about "Cancer & Children") Wilms' tumor usually affects just one kidney, although in some cases, both kidneys are affected. Wilms' tumor is usually found only after the tumor has grown quite large. In fact, ACS says the average weight of a newly found Wilms' tumor is about half a pound. Even so, NCI says Wilms' tumor is highly curable.

According to ACS, adults may develop Wilms' tumors or children may develop renal cell carcinoma, but these cases are very rare. Other types of kidney cancer that are considered rare include clear cell sarcoma of kidney (CCSK) and rhabdoid tumor. Another type of cancer, transitional cell carcinoma, affects the renal pelvis. It is similar to bladder cancer and is often treated like bladder cancer, according to the National Cancer Institute (NCI).

Symptoms

ACS says there is no blood or urine test that can screen for kidney cancer. (Read about "Cancer Check-ups") As a result, kidney cancer can be quite advanced before it is discovered. Blood in the urine is often a symptom of kidney cancer in adults, but can also be the sign of other kidney disease. (Read about "Kidney Disease") One thing is certain, blood in the urine of an adult or a child is a sign of the need for a visit to the doctor to find out the exact reason.

When there are symptoms of RCC, according to NCI and ACS, they can include:

• blood in the urine
• lump or mass in the kidney area
• lump or mass in the belly
• low back pain without having an injury there
• weight loss
• loss of appetite
• fatigue
• fevers with no sign of infections
• high blood pressure
• fluid retention and a swelling of the extremities

TCC may have no symptoms in the early stages. Symptoms may appear only when the tumor grows. You should see your doctor if you develop the following symptoms.

• blood in the urine
• a pain in the back that doesn't go away
• extreme tiredness
• weight loss with no known reason
• painful or frequent urination

Wilms' tumors often produce no symptoms, until there is a noticeable swelling in the abdomen. When there are symptoms of Wilms' tumor, they can include:

• swelling or hard mass in the abdomen
• stomach pain
• fever
• blood in the urine

Again, these symptoms can indicate a number of problems, but if you notice these symptoms, see a doctor right away.

Risk factors

The risk factors for RCC are many. Some of them are genetic and uncontrollable but others are lifestyle or other environmental issues that can be avoided. NCI and ACS list the following:

• Age - RCC is mostly found in people 50-70 years of age.
• Sex - men are twice as likely to get RCC.
• Genetics - a family history of RCC or certain other inherited diseases such as von Hippel-Lindau syndrome. (Read about "Genetics" "Family Health History")
• Smoking doubles the risk (Read about "Quit Smoking")
• Earlier use of painkillers containing phenacetin. They have not been available for 2 decades in the United States
• Exposure to Asbestos or Cadmium
• Excess weight (Read about "Losing Weight")
• High fat diet (Read about "Low Fat Food Tips")
• Long-term dialysis

NCI lists things we can change as the major risk factors for TCC. They include:

• Misusing certain pain medicines, including over-the-counter pain medicines, for a long time (Read about "Medicine Safety")
• Being exposed to certain dyes and chemicals used in making leather goods, textiles, plastics, and rubber
• Smoking cigarettes

The risk factors for Wilms' tumor are less clear. Family history may play a role. (Read about "Family Health History") In addition, there is a strong link between Wilms' tumors and certain kinds of birth defects, according to ACS. About 10 percent of patients with Wilms' tumor also have birth defects. (Read about "Birth Defects")

Diagnosis

Different tests can be used to check for kidney cancer.

Tests include:

• ultrasound, which uses sound waves (Read about "Ultrasound Imaging")
• CT scan, which uses computers and x-rays to create a detailed picture (Read about "CT Scan - Computerized Tomography")
• MRI, which uses magnetic fields to create detailed pictures (Read about "MRI - Magnetic Resonance Imaging")
• biopsy, in which a sample of cells are removed and tested (Read about "Biopsy")
• x-rays, which can be used in conjunction with a dye to produce a clearer picture (Read about "X-Rays")
• cystoscopy, which uses a long narrow tube to look inside the bladder (Read about "Endoscopy")

Staging

A doctor needs to know the stage of the disease to plan treatment. The following stages are used for RCC and TCC, according to NCI:

RCC

• Stage I

  Cancer is found only in the kidney and is smaller than seven centimeters.

• Stage II

  The tumor is larger than seven centimeters but is still confined to the kidney.

• Stage III

  Cancer has spread to the main blood vessel that carries clean blood from the kidney (renal vein), to the blood vessel that carries blood from the lower part of the body to the heart (inferior vena cava), or to lymph nodes around the kidney. (Lymph nodes are small, bean-shaped structures that are found throughout the body; they produce and store infection-fighting cells.) (Read about "The Lymph System")

• Stage IV

  Cancer has spread to nearby organs such as the bowel or pancreas or has spread to other places in the body such as the lungs.

TCC

• Stage 0 (Papillary Carcinoma and Carcinoma in Situ)

  Abnormal cells are found in tissue lining the inside of the renal pelvis or ureter. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is divided into stage 0a and stage 0is, depending on the type of tumor:

  • Stage 0a may look like tiny mushrooms growing from the lining. Stage 0a is also called noninvasive papillary carcinoma.
  • Stage 0is is a flat tumor on the tissue lining the inside of the renal pelvis or ureter. Stage 0is is also called carcinoma in situ.

• Stage I

  Cancer has formed and spread through the lining of the renal pelvis and/or ureter, into the layer of connective tissue.

• Stage II

  Cancer has spread through the layer of connective tissue to the muscle layer of the renal pelvis and/or ureter.

• Stage III

  Cancer has spread to the layer of fat outside the renal pelvis and/or ureter; or into the wall of the kidney.

• Stage IV

  Cancer has spread to at least one of the following:

  • A nearby organ
  • The layer of fat surrounding the kidney
  • One or more lymph nodes
  • Other parts of the body

  TCC can also be described as localized, regional, or metastatic. Localized is when cancer is found only in the kidney. Regional is when the cancer has spread to tissues around the kidney and to nearby lymph nodes and blood vessels in the pelvis. And metastatic is when the cancer has spread to other parts of the body.

Wilms' tumor

• Stage I

  Cancer is found only in the kidney and can be completely removed by surgery.

• Stage II

  Cancer has spread beyond the kidney, to fat or soft tissue or blood vessels. The cancer can be completely removed by surgery.

• Stage III

  Cancer has spread within the abdomen and cannot be completely removed by surgery. The cancer may have spread to the lymph nodes (small bean-shaped structures found throughout the body that produce and store infection-fighting cells) near the kidney, blood vessels or the peritoneum (tissue that lines the abdomen and covers most organs in the abdomen). (Read about "The Lymph System")

• Stage IV

  Cancer has spread to other parts of the body, such as the lungs, liver (Read about "The Liver"), bone and/or brain. (Read about "The Brain")

• Stage V

  Cancer cells are found in both kidneys when the disease is first diagnosed.

Treatments

ACS calls surgery the main treatment for kidney cancer. An operation to remove the kidney is called a nephrectomy. Usually the entire kidney, along with the adrenal gland and some fatty tissue, is removed. Partial removal of the kidney is done in some instances. Nephron-sparing surgery, in which the tumor is removed but not the kidney, may be an option in some cases. The surgery may be done conventionally or robotically. (Read about "Robotic Surgery")

Radiation can also be used (Read about "Radiation Therapy"), sometimes as the main therapy and sometimes to shrink the tumor prior to surgery. Biological therapy is also an option. Biological therapy uses the body's natural ability to fight cancer. (Read about "The Immune System") Chemotherapy isn't very successful against RCC, according to ACS, though it can be used against Wilms' tumor. (Read about chemotherapy, radiation, biological and other cancer therapies in "Cancer Treatments")

A procedure called arterial embolization can also be done. It cuts off the blood supply to the kidney and kills the cancer cells. Sometimes it is done before an operation to make surgery easier. When surgery is not possible, embolization may be used to help relieve the symptoms of kidney cancer. In addition, NCI says radiofrequency thermal ablation, which uses intense heat to destroy tumors, is also now being used, particularly in cases where kidney cancer is hereditary and/or causes multiple or recurrent tumors.

More Cancer Information:

    Cancer Check-ups

    Cancer Support

    Cancer Treatments

    Reduce Cancer Risks

    Cancer Glossary

For a list of individual types of cancer, see Cancer: What It Is

Related Information:

    Bone Loss and Kidney Disease

    Diabetes and Kidney Disease