What is kidney cancer?
Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults and is responsible for around 80% of cases. It is also known as renal adenocarcinoma and historically was referred to as hypernephroma.
This page focuses on renal cell carcinoma. For more information on other types of kidney cancer visit Cancer Research UK’s section on renal cancer.
What causes kidney cancer?
Kidney cancer is caused by mutations in the DNA of the cells found in the kidney. When this occurs, those cells begin to grow quickly, causing a growth or tumour. This can continue to grow and may spread when cells break off and metastasise to other parts of the body. Most people with RCC develop it for no apparent reason.
Renal cell carcinoma is the 8th most common cancer in the UK
Who does kidney cancer affect?
RCC is one of the most common types of cancer in the UK, but rare in people under the age of 50. However, certain groups of people are at increased risk of developing RCC. Risk factors include:
- Smoking – Smoking is a major preventable risk factor for kidney cancer. On average smokers have a 25 to 50% increase in risk of kidney cancer. This reduces as soon as someone stops smoking.
- Obesity – Being overweight or obese is an established risk factor for kidney cancer, increasing the chance by 20 to 25%.
- High blood pressure – Kidney cancer risk increases by around 20 to 60% in people with a history of high blood pressure (hypertension).
- Family history – People with a close family member with kidney cancer have an increased risk of being diagnosed themselves.
- Inherited syndromes – Approximately 2% of cases are associated with inherited syndromes like hereditary papillary renal cell carcinoma and Von Hippel-Lindau disease.
- Chemicals – Exposure to certain chemicals, in particular asbestos or cadmium, can increase the risk of kidney cancer.
- Long-term dialysis – Patients on long-term kidney dialysis for kidney failure have a higher risk of developing kidney cancer.
- Polycystic kidney disease – This genetic condition puts people at increased risk.
What are the symptoms of kidney cancer?
Early stages of kidney cancer are often asymptomatic (showing no symptoms), although as the cancer develops there may be blood found in urine (known as haematuria).
Haematuria is often the first symptom, and it is usually painless and intermittent. All cases of blood in the urine should be investigated, initially by seeing your GP.
Other symptoms include:
- Loin (side) pain (40%)
- High blood pressure (30%)
- Being generally unwell, or loss of appetite or weight loss (30%)
- Abdominal mass (25%)
- Pain or breathing difficulties due to spread of the cancer to bone, lungs, or other organs. Up to 25% of tumours have spread by the time of diagnosis.
In nearly half of cases the cancer is detected incidentally as scans are done for other conditions
How is kidney cancer diagnosed?
The diagnosis of RCC is usually initially suggested by an ultrasound scan of the kidney. This is usually followed by a staging computed tomography (CT) scan of the abdomen and chest to see if the cancer has spread.
Imaging studies usually provide enough information for your doctor to decide if an operation is needed. Most kidney cancers are referred to as specialist hospitals and are discussed by a team of doctors including kidney surgeons, radiologists, oncologists (cancer specialists) and pathologists, in their multi-disciplinary team (MDT) cancer meeting.
Kidney biopsy is not usually suggested for two reasons:
- There is a small chance that the cancer in the kidney may be spread as a result of taking a biopsy.
- Biopsies have about a 20% chance of missing any cancer that is present. A negative biopsy can therefore be misleading and lead to delayed treatment.
How is kidney cancer treated?
There are different options for treating kidney cancer and which option is best for you will depend on lots of factors.
Surgery is the most effective treatment for RCC. If the cancer has not spread, surgery alone may be curative. If it has spread, surgery to remove the affected kidney may still be advised, often in addition to other treatments. This may improve symptoms and lengthen survival.
Radical nephrectomy – an operation to remove the entire affected kidney is the most common treatment.
Laparoscopic (keyhole) surgery – this is now regarded as the standard approach. However, it still requires a cut the size of the kidney and tumour in order to fully remove the cancer. Laparoscopy is usually possible for all but the largest or most complex tumours, resulting in shorter recovery time and better cosmetic results.
Partial nephrectomy – this is removal of only the part of the kidney with the tumour and may be suitable for small tumours (less than 4cm).
Open surgery – surgery with a larger incision may be used for the largest and most complex tumours, which involve extension of the tumour into the veins.
Embolisation – this involves blockage of the kidney artery and may be recommended for larger and more complex tumours.
Removal of secondary tumour – occasionally, surgery is done to remove a secondary tumour that has spread from the original kidney tumour to another part of the body, usually a lung.
There are newer treatments, some of which are experimental, that tend to be less invasive than surgery to remove the kidney. These include cryotherapy, where the tumour is frozen, and radio frequency ablation, where the tumour is heated using high-frequency electricity and high focused ultrasound (HIFU). These tend to only be appropriate where there are multiple tumours in both kidneys and in elderly patients with small tumours.
Targeted kidney cancer therapies such as sunitinib, sorafenib, pazopanib, axitinib, tivozanib, temsirolimus, everolimus, bevacizumab and interferon-alpha have improved the outlook for RCC.
Although, these may allow patients to live longer if there is evidence of spread from the kidney, these therapies do not usually offer a cure. There are currently a number of clinical trials to look at the best way to use these drugs.
What is the prognosis for kidney cancer?
If a small cancer is confined within a kidney, and the patient is otherwise well, the outlook is good – with up to 95% surviving at least 5 years after surgery.
If the kidney cancer is diagnosed when the cancer has already spread, a cure is less likely. However, treatment can often slow down the progression of the cancer.