Kidney cancer is characterized by a tumor that begins in the kidneys. The kidneys are bean-shaped organs that help remove excess water and waste from the body through urine. Tumors that originate in the kidneys are common, with more than 60,000 people in the United States diagnosed with kidney cancer each year.
Types of Kidney Cancer
There are several different types, classified by where they originate, of kidney cancer. The most common type of kidney cancer is renal cell carcinoma, which begins in the small tubes found within the kidney. Renal cell carcinoma accounts for most cases of kidney cancer. It usually begins as a single mass within the kidney, and can usually be identified before it spreads to other areas.
The other common types of kidney cancer include the following:
- Transitional cell carcinomas
- Wilms tumors
- Renal sarcomas
Benign tumors are often found in the kidneys as well, but they do not usually cause any harm to the patient.
Causes of Kidney Cancer
Like other types of cancer, the specific cause of kidney cancer is unknown. It is believed, however, to be the result of a specific gene mutation, which can be inherited or acquired. Some people may be at a higher risk for developing kidney cancer, including those who:
- Are obese
- Are regularly exposed to certain substances
- Have a family history of kidney cancer
- Have high blood pressure
- Take certain medications
- Have advanced kidney disease
A person may be able to reduce the risk of developing kidney cancer by eliminating the factors that are not controlled by genetics. Obesity and smoking are common risk factors for many conditions, and should be managed in order to improve health.
Symptoms of Kidney Cancer
Those with kidney cancer do not often experience any symptoms until the disease has progressed to its later stages, at which point they may notice:
- Blood in the urine
- Back pain
- Weight loss
- Swelling in the legs or ankles
- Lump in the abdomen or side
If left untreated, kidney cancer may spread to other areas of the body and symptoms may worsen.
The Diagnosis of Kidney Cancer
If kidney cancer is suspected, a doctor will perform a physical examination, and may also conduct the following tests to confirm diagnosis:
- CT scan
- MRI scan
- Blood test
The Stages of Kidney Cancer
Once kidney cancer is diagnosed, the doctor will determine which stage of cancer is present in the bladder and body. The stages of kidney cancer include:
In Stage I kidney cancer, the tumor is confined to the kidney. Cancerous cells have not spread to lymph nodes or other organs.
With stage II cancer, the tumor is confined to the kidney but is larger in size. It has not spread to lymph nodes or other organs.
With stage III cancer, the cancer has spread into the lymph nodes adjacent to the kidney. It may have possibly spread into the veins leading from the kidney to the heart.
In stage IV kidney cancer, the cancer has spread outside the kidney to adjacent organs. The cancer may have spread to the lungs, liver, colon, bowels or abdominal wall.
Treatment of Kidney Cancer
There are several different treatment options available for kidney cancer. The best treatment for each patient depends on the severity and location of the disease. Surgery, because it is the only method to thoroughly remove the tumor, is often the most effective treatment for kidney cancer. Surgery may involve removing just the tumor or removing the entire kidney.
For some patients, surgery may not be an option. Less invasive treatments are available to treat the disease for these patients, and may include the following methods:
- Radiofrequency ablation
- Biological therapy
After a thorough evaluation of the patient's condition, a doctor will be able to determine which treatment option is best.
- National Institutes of Health
- Centers for Disease Control and Prevention
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- U.S. Department of Health & Human Services
- U.S. National Library of Medicine