What is kidney cancer?

Kidney cancer starts in the cells of the kidney. A cancerous (malignant) tumour is a group of cancer cells that can grow into nearby tissue and destroy it. The tumour can also spread (metastasize) to other parts of the body.

The kidney is part of the urinary system. The 2 kidneys are on either side of the backbone, deep inside the upper part of the abdomen.

Diagram of the location of the kidneys
Diagram of the location of the kidneys

On the top of each kidney is an adrenal gland. The kidneys make urine (pee) by filtering water and waste material from the blood. Inside each kidney is a network of millions of small tubes called nephrons. Each nephron is made up of a tubule and a corpuscle. Tubules are tiny tubes that collect the waste materials and chemicals. Corpuscles have a clump of tiny blood vessels that filter the blood.

Cells in the kidneys sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous (benign) conditions such as cysts. They can also lead to non-cancerous tumours such as papillary renal adenoma.

But in some cases, changes to kidney cells can cause kidney cancer. Most often, kidney cancer starts in the cells that line the tubules. This type of cancer is called classic renal cell carcinoma, or clear cell carcinoma. Cancers that start from other cells in the kidney are called non-clear cell carcinoma.

Rare types of kidney cancer can also develop. These include renal sarcoma and primary renal lymphoma.

Expert review and references

  • DeVelasco G, Signoretti S, Rini BI, et al . Uncommon tumors of the kidney. Raghavan D, et al (eds.). Textbook of Uncommon Cancer. 5th ed. Wiley Blackwell; 2017: 4:19-40.
  • Lane BR, Canter DJ, Rin BL, et al . Cancer of the kidney. DeVita VT Jr, Lawrence TS, Rosenberg SA. Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2015: 63:865-884.
  • Martini FH, Timmons MJ, Tallitsch RB. Human Anatomy. 7th ed. San Francisco: Pearson Benjamin Cummings; 2012.

The kidneys

The kidneys are part of the urinary system. Learn about the kidneys, including their function.

Cancerous tumours of the kidney

Renal cell carcinoma is the most common type of kidney cancer, and there are several different types. Learn about the different kinds of kidney cancer.

Non-cancerous tumours and conditions of the kidney

Non-cancerous tumours of the kidney include adenoma, oncocytoma and angiomyolipoma. Learn about diagnosing and treating benign kidney tumours.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

We do our best to make sure that the information we provide is accurate and reliable but cannot guarantee that it is error-free or complete.

The Canadian Cancer Society is not responsible for the quality of the information or services provided by other organizations and mentioned on cancer.ca, nor do we endorse any service, product, treatment or therapy.

1-888-939-3333 | cancer.ca | © 2024 Canadian Cancer Society