What is kidney cancer?
Kidney cancer is a cancer that starts in the kidneys. It may also be referred to as renal cancer or renal carcinoma.
In 2018, it was estimated that an Ontario male’s lifetime probability of developing kidney cancer is 1 in 64. An Ontario female’s lifetime risk is 1 in 121.*
Kidneys are about the size of a fist and there is one on either side of the spine near the bottom of the rib cage. Most people have 2 kidneys, although you can survive with only 1 functioning kidney. Kidneys are part of the urinary system, also referred to as the renal system.
Kidneys help to keep you healthy. Learn how you can protect yourself against kidney (renal) cancer.
Kidneys are essential organs that perform a number of important functions. Within each kidney there are:
- Tiny filters (called nephrons) that clean waste and water from the blood
- Tubes (called tubules) that
- reabsorb water, which helps to keep us hydrated and helps to regulate levels of important electrolytes, such as potassium and sodium (salt)
- send waste products to be excreted in the urine
- A funnel-like structure, called the renal pelvis, that directs urine through the ureter into the bladder, where it is stored until you urinate
The kidneys also produce a number of important hormones. For example, hormones produced by the kidneys help to regulate blood pressure, blood sugar and the production of red blood cells. The functioning of the kidneys can be impaired by factors such as disease, infections, inherited or congenital disorders, or benign or cancerous tumours.
Benign or non-cancerous changes in the cells that make up the kidneys can result in the formation of:
- cysts, which are round or oval fluid-filled pockets
- benign tumours
In some cases, tumours in the kidney may become cancerous. Malignant (cancerous) tumours may grow uncontrollably or interfere with the normal functioning of the kidneys.
The most common form of kidney cancer is called renal cell carcinoma. This cancer starts in the tubules and accounts for about 90% of all cases of kidney cancer. Less commonly, cancer can form in the renal pelvis (the top part of the ureter) or the collecting ducts (part of the tubule system).
*The source of data used in the My CancerIQ Kidney Cancer Risk Assessment is based on people who were assigned male or female at birth. Because of this, gender binary language (male, female, man, woman) may sometimes be used. If your gender is different from your sex assigned at birth, My CancerIQ may not assess your risk accurately. Talk to your doctor or nurse practitioner about your risk of developing kidney cancer.