Kidney cancer forms in tissues of the kidneys. Kidney cancer includes renal cell carcinoma (cancer that forms in the lining of very small tubes in the kidney that filter the blood and remove waste products) and renal pelvis carcinoma (cancer that forms in the center of the kidney where urine collects). It also includes Wilms tumor, which is a type of kidney cancer that usually develops in children under the age of 5.
Kidney cancer develops most often in people over 40, but no one knows the exact causes of this disease. Doctors can seldom explain why one person develops kidney cancer and another does not. However, it is clear that kidney cancer is not contagious. No one can "catch" the disease from another person. Research has shown that people with certain risk factors are more likely than others to develop kidney cancer. A risk factor is anything that increases a person's chance of developing a disease. Studies have found the following risk factors for kidney cancer:
Smoking: Cigarette smoking is a major risk factor. Cigarette smokers are twice as likely as nonsmokers to develop kidney cancer. Cigar smoking also may increase the risk of this disease.
Obesity: People who are obese have an increased risk of kidney cancer.
High blood pressure: High blood pressure increases the risk of kidney cancer.
Long-term dialysis: Dialysis is a treatment for people whose kidneys do not work well. It removes wastes from the blood. Being on dialysis for many years is a risk factor for kidney cancer.
Von Hippel-Lindau (VHL) syndrome: VHL is a rare disease that runs in some families. It is caused by changes in the VHL gene. An abnormal VHL gene increases the risk of kidney cancer. It also can cause cysts or tumors in the eyes, brain, and other parts of the body. Family members of those with this syndrome can have a test to check for the abnormal VHL gene. For people with the abnormal VHL gene, doctors may suggest ways to improve the detection of kidney cancer and other diseases before symptoms develop.
Occupation: Some people have a higher risk of getting kidney cancer because they come in contact with certain chemicals or substances in their workplace. Coke oven workers in the iron and steel industry are at risk. Workers exposed to asbestos or cadmium also may be at risk.
Gender: Males are more likely than females to be diagnosed with kidney cancer. Each year in the United States, about 20,000 men and 12,000 women learn they have kidney cancer.
Most people who have these risk factors do not get kidney cancer. On the other hand, most people who do get the disease have no known risk factors. People who think they may be at risk should discuss this concern with their doctor. The doctor may be able to suggest ways to reduce the risk and can plan an appropriate schedule for checkups.
Many people with kidney cancer want to take an active part in making decisions about their medical care. They want to learn all they can about their disease and their treatment choices. However, shock and stress after the diagnosis can make it hard to think of everything they want to ask the doctor. It often helps to make a list of questions before an appointment. To help remember what the doctor says, people may take notes or ask whether they may use a tape recorder. Some also want to have a family member or friend with them when they talk to the doctor—to take part in the discussion, to take notes, or just to listen.
The doctor may refer the patient to a specialist, or the patient may ask for a referral. Specialists who treat kidney cancer include doctors who specialize in diseases of the urinary system (urologists) and doctors who specialize in cancer (medical oncologists and radiation oncologists).
Before starting treatment, a person with kidney cancer might want a second opinion about the diagnosis and the treatment plan. Some insurance companies require a second opinion; others may cover a second opinion if the patient or doctor requests it.
Treatment depends mainly on the stage of disease and the patient's general health and age. The doctor can describe treatment choices and discuss the expected results. The doctor and patient can work together to develop a treatment plan that fits the patient's needs. People do not need to ask all their questions or understand all the answers at once. They will have other chances to ask the doctor to explain things that are not clear and to ask for more information.
People with kidney cancer may have surgery, arterial embolization, radiation therapy, biological therapy, or chemotherapy. Some may have a combination of treatments. At any stage of disease, people with kidney cancer may have treatment to control pain and other symptoms, to relieve the side effects of therapy, and to ease emotional and practical problems. This kind of treatment is called supportive care, symptom management, or palliative care. A patient may want to talk to the doctor about taking part in a clinical trial, a research study of new treatment methods.