See what the different types and grades of kidney cancer mean, and how they affect your treatment options.
Types of kidney cancer
The type of kidney cancer you have tells you what type of cell it started in. Knowing this helps your doctor decide which treatment you need.
Renal cell cancer
Renal cell cancer is the most common type of kidney cancer in adults. More than 8 in every 10 (80%) kidney cancers diagnosed in the UK are this type. It is also called renal cell adenocarcinoma and occasionally hypernephroma.
In renal cell cancer, the cancerous cells start in the lining of the tubules (the smallest tubes inside the nephrons). Tubules help filter the blood and make urine.
The kidneys are made up of different types of cells. The type of cancer you have depends on the type of cell the cancer starts in. There main types of renal cell cancer are:
- clear cell - around 75 out of 100 renal cell cancers (75%)
- papillary - around 10 in 100 renal cell cancers (10%)
- chromophobe - around 5 in 100 renal cell cancers (5%)
Rare types of renal cell cancer include carcinoma of the collecting ducts and renal medullary carcinoma. Sometimes kidney cancers can contain more than one cell type.
It seems that any type of renal cell cancer can become sarcomatoid. This means that the cells of the cancer look like the cells of a sarcoma – a cancer of the body’s supporting tissues, such as muscles, nerves, fat, blood vessels and fibrous tissues. If a kidney cancer is a sarcomatoid type it may have a worse outlook than non sarcomatous kidney cancers.
Transitional cell cancer of the kidney or ureter
Around 7 or 8 out of every 100 kidney cancers (7 to 8 %) diagnosed in the UK are transitional cell cancers (TCCs) of the renal pelvis. The renal pelvis is the central area of the kidney where urine collects before it goes down the ureter to the bladder.
The treatment for this type of kidney cancer is similar to the treatment for bladder cancer.
A type of kidney cancer called Wilms' tumour can affect children. This is different from kidney cancer in adults.
Grades of kidney cancer
The grade of a cancer tells you how much the cancer cells look like normal cells. It is decided by looking at the cancer cells under a microscope:
- the more they look like normal kidney cells, the lower the grade
- the less they look like normal kidney cells (abnormal), the higher the grade
Kidney cancers are graded 1-4. This is called the Fuhrman system. Low grade cancers tend to grow more slowly and are less likely to spread than high grade cancers.
The grade tells your doctor how the cancer might behave and what treatment you need. The main factor for deciding on the best treatment is whether your cancer has spread away from the kidney or not.