The kidneys are part of the ‘urinary system’, found near the middle of the back on either side of the spine. The main job of the kidneys is to filter blood to remove water that isn’t needed, as well as salt and waste products. The kidneys then turn all these waste products into urine.
The kidneys also have other jobs, including:
In the kidneys, there are different types of cells. Based on where and in what type of cell the cancer starts, different kinds of kidney cancer can develop. One of these is called ‘renal cell carcinoma’ or RCC.
RCC is the most common type of kidney cancer, making up about 9 out of 10 kidney cancers.
There are also several subtypes of RCC. The subtype a patient is diagnosed with can be used to decide the type of treatment they are given. Subtypes are found by looking at samples of the tumour cells under a microscope. The most common subtype is ‘clear-cell RCC’, which is identified by small, clear or very pale cells. About 7 out of every 10 patients with RCC will have clear-cell RCC. Other subtypes include ‘papillary RCC’ (about 1 in every 10 patients) and ‘chromophobe RCC’ (about 5 in every 100 patients).
It is not fully understood what leads to the development of RCC, but there are some things that can increase a person’s chances of getting the disease, called ‘risk factors’. Some risk factors are:
The most common symptom of RCC is blood in the urine, known as ‘haematuria’. This can often appear to come and go, which can mean that the cancer is at an early stage and more easy to treat. In some patients a lump or swelling can be felt on the back in the area of the kidneys. More general symptoms include:
If a person thinks some of the symptoms they have are caused by RCC, there are different tests the doctor can do to find out whether there is a kidney problem. These include urine testing to see if there is any blood or cancer cells in the urine, and blood tests to see if there are any abnormal changes that point towards cancer. A person might also have an ultrasound scan, where sound waves are used to make a picture of organs inside their body, or a CT scan, where X-rays are used to make a 3D image.
After a person is diagnosed, doctors will assess the tumour to find out how serious the cancer is and whether it has spread any further in the body. This is called ‘cancer staging’, and the cancer will be given a score from 1 (the earliest stage) to 4 (the latest stage). This will help the doctor decide what the best treatment is for each patient.
If a person is at a high risk of developing RCC, possibly due to a genetic or hereditary risk, they might have regular screening in the form of a scan every year. This can help doctors to detect RCC as early as possible. However, there is no reliable screening process for RCC for the general population.
RCC is described as ‘localised’ if the cancer has not spread outside of the kidneys. The doctor may refer to this as stage 1, 2 or 3. If this is the case, surgery to remove the tumour, or part or all of the kidney, is the most common treatment. Sometimes extra treatment is given before surgery to shrink the tumour. This is called ‘neoadjuvant therapy’. Alternatively, treatment can be given after surgery to make sure all the cancer cells are gone to help lower the risk of the cancer coming back. This is called ‘adjuvant therapy’.
RCC is described as ‘advanced’ when it has spread to a part of the immune system called ‘lymph nodes’ or to other organs. The doctor may call this stage 4 cancer. The chance of the cancer getting worse is also assessed as ‘low-risk’, ‘intermediate-risk’ or ‘high-risk’. In advanced RCC the main kidney tumour, or the kidney itself, may still be removed by surgery. If a person has tumours that have spread to other parts of the body, they will usually require a different treatment. The treatment options that are best for each patient may also depend on the type of RCC they have. The doctor will be able to advise on other available treatment options.
There are two types of drugs that are used to treat advanced RCC. These are ‘targeted therapies’ and ‘immunotherapy’.
Targeted therapies can stop messages in the cells that cause cancer to grow uncontrollably. One target for RCC treatments is a protein called ‘VEGF’, which is involved in the growth of new blood vessels by the cancer (called ‘angiogenesis’). Drugs that inhibit VEGF can stop the cancer from growing. Other targets are ‘tyrosine kinases’ and a protein called ‘mTOR’. Tyrosine kinases and mTOR help cancer cells to grow and divide. Drugs that stop tyrosine kinases or mTOR from working can stop the cancer from growing or may slow it down.
Immunotherapy works by helping the immune system to deal with cancer cells. There are different types of immunotherapy; some help the immune system to more easily recognise cancer cells and others boost the strength of the immune system to attack the cancer cells. Immunotherapies are being used to treat patients. Newer ones, called ‘checkpoint inhibitors’, block the activity of substances in the body that stop the immune system from attacking cancer cells. These are being tested right now in clinical trials. Some of the newer immunotherapy agents can already be used to treat RCC.
Current research in RCC is mainly looking at using checkpoint inhibitors with other drugs to increase the number of patients who can be helped with this treatment. Clinical trials are looking into using checkpoint inhibitors as the starting treatment for advanced RCC and as treatment after surgery for localised RCC.