Kidney cancer is cancer that begins in the kidneys. Your kidneys are two bean-shaped organs, each about the size of your fist. They’re located behind your abdominal organs, with one kidney on each side of your spine.
In adults, renal cell carcinoma is the most common type of this cancer. Other less common types of kidney cancer can occur. Young children are more likely to develop a kind of cancer called Wilms’ tumor.
The incidence of this cancer seems to be increasing. One reason for this may be the fact that imaging techniques such as computerized tomography (CT) scans are being used more often. These tests may lead to the accidental discovery of more cancers. It is often discovered at an early stage, when the cancer is small and confined to the kidney
Kidney cancer usually doesn’t have signs or symptoms in its early stages. In time, signs and symptoms may develop, including:
- Blood in your urine, which may appear pink, red or cola colored
- Pain in your back or side that doesn’t go away
- Loss of appetite
- Unexplained weight loss
When to see a doctor
Make an appointment with your doctor if you have any persistent signs or symptoms that worry you.
It’s not clear what causes most kidney cancers.
Doctors know that kidney cancer begins when some kidney cells develop changes (mutations) in their DNA. A cell’s DNA contains the instructions that tell a cell what to do. The changes tell the cells to grow and divide rapidly. The accumulating abnormal cells form a tumor that can extend beyond the kidney. Some cells can break off and spread (metastasize) to distant parts of the body.
Factors that can increase the risk of kidney cancer include:
- Older age. Your risk of cancer increases as you age.
- Smoking. Smokers have a greater risk of cancer than nonsmokers do. The risk decreases after you quit.
- Obesity. People who are obese have a higher risk of kidney cancer than people who are considered to have a healthy weight.
- High blood pressure (hypertension). High blood pressure increases your risk of cancer.
- Treatment for kidney failure. People who receive long-term dialysis to treat chronic kidney failure have a greater risk of developing cancer.
- Certain inherited syndromes. People who are born with certain inherited syndromes may have an increased risk of this cancer, such as those who have von Hippel-Lindau disease, Birt-Hogg-Dube syndrome, tuberous sclerosis complex, hereditary papillary renal cell carcinoma or familial renal cancer.
- Family history of kidney cancer. The risk of cancer is higher if close family members have had the disease.