Causes of Kidney Cancer

The American Urological Association states that 2 percent of all cancers in the United States are related to the kidneys. They also stress that if caught in the early stages, the survival rate is 79 to 100 percent. Understanding the potential causes and risk factors may help you prevent this disease or improve the chance of early detection.

Definition

• There are three types of kidney cancer: renal cell carcinoma, renal pelvis carcinoma, and Wilms tumor. Renal cell carcinomas begin in the lining of the small tubes in the kidneys that filter the blood. Renal pelvis carcinoma begins in the center of the kidney where urine collects before it goes to the bladder. Wilms tumor is usually diagnosed before the age of five. According to the American Cancer Society, scientists do not know exactly what causes kidney cancer, but they have recognized risk factors and they continue to identify genetic influences.

Inherited Gene Changes

• There are two types of genes that influence kidney cancer, oncogenes and tumor suppressor genes. Tumor suppressor genes inhibit the growth of cancer while oncogenes increase the risk of cancerous growth. A gene called the VHL gene normally stops cells from growing out of control but if it is damaged it causes von Hippel-Lindau disease, which is associated with renal cell carcinoma. The genes believed to cause renal cell carcinoma are tumor suppressor genes that are damaged. A form of inherited cancer called papillary renal cell carcinoma is caused when an oncogene becomes activated.

  There are other inherited diseases that impact kidney cancer, including leiomyomatosis and Birt-Hogg-Dube syndrome. Both of these diseases cause other benign tumors---one in the smooth muscles and the other in the skin----yet they also increase the risk of developing kidney cancer.

Acquired Gene Changes

• Most of us think of gene mutations as being something we are born with. However, mutations to oncogenes and suppressor genes can also occur throughout life rather than being inherited. The American Cancer Society states that three out of four people with non-inherited kidney cancer also have changes in the VHL gene, indicating that the genetic change was acquired rather than inherited. Acquired changes can be triggered by environmental factors such as exposure to cancer-causing chemicals.

Cigarette Smoking

• The relationship of smoking and second-hand smoke to kidney cancer was studied by researchers at the University of Florida. Their results, published in the December 2008 issue of "BMC Cancer," confirmed the association between smoking and renal cell carcinoma. They also established a potential connection between second-hand smoke and kidney cancer but they acknowledged that additional studies were needed.

Lifestyle Factors

• Even though researchers don't know exactly how, they have established that obesity increases the risk of developing kidney cancer. The American Cancer Society states that exposure to substances in the workplace affect the kidneys, including asbestos, cadmium, benzene and organic solvents. High blood pressure and medications used to treat that disease have been associated with increased risk for kidney cancer.

Symptoms

• In the early stages of kidney cancer you may experience vague symptoms like fatigue, fever, loss of appetite or night sweats. As the cancer progresses symptoms include a lump in your abdomen, unexplained weight loss, and pain in the side or back below the ribs. You may also see blood in the urine, which can appear pink, red or even cola-colored. If the cancer spreads, symptoms will appear that are related to the involved organ. For example, you may experience shortness of breath if it has spread to the lungs and bone pain or fracture if it is in the bones.