What is Kidney Cancer?
Renal cell carcinoma is the most common type of kidney cancer and accounts for more than 90 percent of malignant kidney tumors. Like all cancers, renal cell carcinoma begins small and grows larger over time. Although renal cell carcinoma usually grows as a single mass within the kidney, a kidney may contain more than one tumor. Sometimes tumors may be found in both kidneys at the same time.
Some renal cell carcinomas are noticed only after they have become quite large. Most are found before spreading to other organs through the bloodstream or lymph system. Like most cancers, renal cell carcinoma is difficult to treat once it has spread.
Facts: According to the Illinois State Cancer Registry, in 2008, about 2,050 new cases of kidney and renal pelvic cancer will be diagnosed in Illinois. Of these, about 1,230 will be in men and about 820 will be in women. About 570 Illinoisans are expected to die of kidney and renal pelvic cancer in 2008. Most renal cell carcinomas occur in adults between the ages of 50 and 70 years. They rarely develop in children and young adults.
What are the Causes and Risk Factors of Kidney Cancer?
Researchers have found several important risk factors for renal cell carcinoma, and are beginning to understand how these risk factors can alter the DNA of kidney cells and cause these cells to become cancerous.
The common risk factors include:
Smoking: Cigarette smoking is a major risk factor. It increases the risk of developing renal cell carcinoma by about 40 percent.
Gender: Renal cell carcinoma is about twice as common in men.
Obesity: People who are obese have an increased risk of kidney cancer.
Physical activity: Several studies have found that inactive people are more likely to develop kidney cancer than people who exercise regularly.
Chemicals: Many studies suggest that workplace exposure to certain chemicals and substances increases the risk for renal cell carcinoma. Some of these are asbestos, cadmium (a type of metal), some herbicides, benzene, and organic solvents, particularly trichloroethylene.
Family history: People with a close family history of renal cell cancer, particularly in a brother or sister, have a much greater chance of developing this cancer.
Blood pressure: High blood pressure increases the risk of kidney cancer. People with both high blood pressure and obesity may have a risk that is three times greater than normal.
Kidney dialysis: Long-term kidney dialysis is a risk factor for kidney cancer.
What are the Symptoms of Kidney Cancer?
Common symptoms of kidney cancer include:
- blood in the urine (hematuria)
- low back pain on one side, not associated with injury
- a mass or lump in the abdomen
- unintentional weight loss
- fever that is not associated with a cold, flu or other infection and does not go away after a few weeks
- swelling of ankles and legs (edema)
An infection, cyst or other problems also can cause the same symptoms. It is important to report any of these symptoms to a doctor.
How to Prevent Kidney Cancer
Many cases of renal cell carcinoma can be prevented. To lower your risk:
- Stop smoking—cigarette smoking is responsible for a large percentage of cases.
- Maintain a healthy weight.
- Get treatment for high blood pressure.
- Exercise and eat adequate amounts of fruits and vegetables.
- Avoid workplace exposure to large amounts of harmful substances such as cadmium, asbestos, and organic solvents.