What is Kidney Cancer?

Cancer Research UK states that kidney cancer is the seventh most common cancer in the UK, accounting for 4% of all new cancer cases (2016-2018). There are around 13,300 new kidney cancer cases in the UK every year, that is 36 every day, and each year around a third (34%) of all new kidney cancer cases in the UK are diagnosed in people aged 75 and over.

In males in the UK, kidney cancer is the fifth most common cancer, with around 8,400 new cases every year. In females in the UK, kidney cancer is the tenth most common cancer, with around 4,900 new cases every year. Incidence rates for kidney cancer in the UK are highest in people aged 85 to 89 and are lower in the Asian and Black ethnic groups, and in people of mixed or multiple ethnicities, compared with the White ethnic group.

Kidney cancer rarely affects children, and about 80 to 85 paediatric cases are diagnosed in the UK each year. About 75% of childhood kidney cancer occurs in the under-fives. The most common paediatric kidney cancer is Wilms’ tumour, which accounts for up to 95% of childhood kidney cancers.

Since the early 1990s, kidney cancer incidence rates have increased by almost 88% in the UK. Rates in females have increased by more than 94%, and rates in males have increased by more than 77%. By 2035, incidence rates for kidney cancer are projected to rise by 26% to 32 cases per 100,000 people.

Kidney cancer contributes 3% to total cancer deaths in the UK. More than half of deaths (53%) were in people aged 75 and over (2016-2018), reflecting higher incidence and lower survival for kidney cancer in older people.

What is kidney cancer?

Kidney cancer, also called renal cancer, is a type of cancer that starts in the cells of the kidney. The kidneys are two bean-shaped organs, each about the size of your fist. They are located behind your abdominal organs, with one kidney on each side of your spine.

The kidneys filter the blood to remove waste products, which they convert into urine. Urine is carried from each kidney through a tube called a ureter to the bladder, where it is stored. The ureter and blood vessels enter and exit the kidney through the renal hilum. When you are ready to pass urine, it leaves the bladder through a tube called the urethra. The urethra opens immediately in front of the vagina in women and at the tip of the penis in men.

The kidneys have several other functions, such as blood pressure regulation, acid-base balance, toxin removal, red blood cell production, activation of vitamin D, water balance and electrolyte balance.

Kidney cancer develops when abnormal cells in either of the kidneys start to divide and grow in an uncontrolled way. The cells can grow into surrounding tissues or organs and may spread to other areas of the body. In adults, renal cell carcinoma (RCC) is the most common type of kidney cancer.

There are several different subtypes of RCC, which are named according to the type of cell that is affected, or the appearance of the cancer cells under the microscope. The most common of these is clear cell, which accounts for about 75% of RCCs. Other subtypes include papillary, chromophobe, and collecting duct carcinoma.

What are the signs and symptoms of kidney cancer?

In the early stages most people who are diagnosed with kidney cancer do not have any symptoms. Some people might be having a test for other things and a scan shows that they have a kidney cancer.

In later stages you may notice some symptoms, including:

• Anaemia.
• Blood in your urine.
• Swelling in your ankles or legs.
• Pain in your side that gets worse or does not go away.
• A lump in your side or belly area.
• Weight loss that happens without a reason.
• Feeling less hungry than normal.
• Fever that lasts for a long time and is not caused by a cold or other sickness.
• Running a persistent temperature and sweating heavily, especially at night.
• Feeling very tired.

Sometimes abnormal red blood cell counts and high blood pressure (hypertension) can be symptoms of kidney cancer. Some patients experience a condition called polycythaemia, or thickening of the blood, which can also be a symptom of kidney cancer. Symptoms of polycythaemia are a bad headache and redness of the skin.

Kidney cancer that has spread to other parts of your body can cause other symptoms, including:

• Trouble catching your breath.
• A persistent cough.
• Coughing up blood.
• Pain in your bones.

Having one or more of these symptoms does not mean that you have kidney cancer. Other kidney or urinary tract problems can also cause many of these symptoms. If you notice a combination of any of these symptoms, talk to your doctor right away. Finding and treating kidney cancer early can help prevent other serious health problems.

Signs of childhood kidney tumours include a lump in the tummy, which can often be painless, blood in the urine (called haematuria) and fever. Children with kidney cancer may sometimes have signs and symptoms of high blood pressure (hypertension), such as headaches, feeling tired (lethargy), chest pain, and problems with seeing or breathing. You should check with your child’s doctor if your child has any of these symptoms.

What causes kidney cancer?

With most cancers there is no direct cause and kidney cancer is no exception. For many people the cause of the cancer is never found. However, certain lifestyle factors can increase the risk of developing the disease.

What are the risk factors of kidney cancer?

A risk factor is anything that increases your chance of getting a disease. Some risk factors can be changed, such as smoking, for example, but others cannot be changed such as your gender or family history. Having a risk factor, or even several risk factors, does not mean you will get kidney cancer, but it may increase your risk.

Risk factors for kidney cancer include:

• Age – The risk of developing kidney cancer is highest in people aged 45-75, and tails off in the late seventies.
• Unhealthy diet – An unhealthy diet and being overweight or obese increases the risk of developing kidney cancer. Being overweight means that your body mass index (BMI) is between 25 and 39.9 and being obese means that your BMI is 30 or higher. Your BMI is worked out by using your height and weight – the NHS provides a BMI calculator. Being overweight causes changes in hormones in the body, particularly for women. It could be this change in the body’s hormone balance that increases the risk of kidney cancer. This causes 24 out of every 100 kidney cancers (24%), around a quarter of kidney cancers.
• Smoking – Smoking may double the risk of developing kidney cancer for some people. The longer a person smokes and the more cigarettes they smoke, the greater the risk. Your risk falls if you stop smoking. After 10 years it becomes nearly the same as those who have never smoked.
• Genetic factors – A few people inherit faulty genes that increase their risk of developing kidney cancer. Cancers caused by these faulty genes are called hereditary or familial kidney cancer. Changes in the DNA that makes up the faulty gene make it behave in an abnormal way. Scientists are finding out which genes carry these mistakes in the DNA, which in the future could help doctors predict who is at risk of getting hereditary kidney cancer. Genetic factors, such as a mutation in the von Hippel-Lindau gene, Birt-Hogg-Dubé syndrome, tuberous sclerosis and hereditary clear cell and papillary renal cell cancer, put people at greater risk of developing the disease.
• Gender – Men are twice as likely to suffer from kidney cancer as women.
• Family history – People with a first degree relative, that is a parent, sibling or child with kidney cancer, have about double the risk of developing kidney cancer themselves.
• Certain medical conditions – Certain medical conditions, such as high blood pressure (hypertension) and chronic kidney disease, especially people on long-term kidney dialysis, have an increased risk of developing kidney cysts. This increases the risk of kidney cancer. The dialysis itself is not directly related to the cancer risk. Some research studies have found a link between high blood pressure or high blood pressure medicines and kidney cancer. It is likely that high blood pressure is the link, rather than the medicines. High blood pressure is a known risk factor for kidney disease in general.
• Diabetes – Some studies have found that people with type 1 diabetes have a higher risk of kidney cancer. The risk may be higher in people who use insulin to control their diabetes. But other diabetic medicines such as metformin or pioglitazone don’t seem to increase the risk.
• Previous thyroid cancer – Previous thyroid cancer increases the risk of kidney cancer, possibly due to genetic changes that are common to both types of cancer.
• Previous radiotherapy for testicular or cervical cancer – Previous radiotherapy for testicular or cervical cancer (cancer of the neck of the womb) may slightly increase the risk of developing kidney cancer.
• Long-term regular use of painkillers – Long-term regular use of painkillers, such as ibuprofen, naproxen, phenacetin and Celebrex, is linked to kidney cancer.

Can kidney cancer be prevented?

Although there is no proven way to completely prevent kidney cancer, around 4 in 10 cancers could be prevented by things such as not smoking, keeping a healthy weight and cutting back on alcohol. Not smoking is the best thing you can do to reduce your risk of cancer. Harmful chemicals in cigarette smoke affect the entire body, not just our lungs. If you smoke, the best thing you can do for your health is quit.

What are the stages of kidney cancer?

How far the cancer has progressed and how quickly the cancer is growing or spreading is called staging and grading. Staging Is used to describe how big a cancer is and how far it has already spread. Information from the tests and scans used to diagnose the cancer is used to determine the stage of the disease.

The TNM system is a common system used for staging tumours.

T (tumour) plus a number indicates the size of the primary tumour and how far it has grown.

The number refers to the stages described below:

• T0 – There is no evidence of primary tumour in the kidney.
• T1 – The tumour is less than 7cm in size and is completely contained within the kidney.
• T1a is a tumour less than 4cm in size.
• T1b is a tumour between 4cm and 7cm in size.
• T2 – The tumour is more than 7cm in size and is completely contained within the kidney.
• T2a is a tumour more than 7cm but less than 10cm in size.
• T2b is a tumour more than 10cm in size.
• T3 – The cancer has spread beyond the kidney to the tissues or organs around the kidney, for example a major vein or the adrenal gland.
• T3a is a tumour that has grown into the renal vein or the fat surrounding the kidney.
• T3b is a tumour that has grown into the part of the vena cava (a large vein in the body) which is below the diaphragm.
• T3c is a tumour that has grown into the part of the vena cava which is above the diaphragm, and it is growing into the wall of the vena cava.
• T4 – The cancer has spread beyond the tissues or organs around the kidney to more distant organs in the body.

N (nodes) plus a number indicates that the cancer has spread to nearby lymph nodes.

The number refers to the number of affected lymph nodes:

• N0 – Cancer has not been detected in any lymph nodes.
• N1 – Cancer has spread to one nearby lymph node only.
• N2 – Cancer has spread to more than one nearby lymph node.

M (metastases) plus a number refers to places elsewhere in the body where the cancer has spread. M0 means there are no distant metastases and M1 means distant metastases are present.

The doctor will combine these figures to give an overall staging, e.g. T2 N0 M0, which means the cancer is bigger than 7cm but still confined to the kidney, there is no involvement of lymph nodes and there are no metastases.

Number System – Another staging classification which is sometimes used for kidney cancer is a number system. The cancer is simply said to be stage 1, 2, 3 or 4 (or stage I, II, III, or IV). Again, the stages reflect how large the primary tumour has become, and whether the cancer has spread to lymph nodes or other areas of the body. A stage 4 tumour is often referred to as an advanced cancer.

The number system used for kidney cancer is as follows:

• Stage 1 – The cancer is confined to the kidney and is less than 7cm in size.
• Stage 2 – The cancer is bigger than 7cm but still confined to the kidney.
• Stage 3 – The cancer has started to spread outside the kidney to the adrenal gland or a major vein nearby. The cancer may have spread to no more than one nearby lymph node.
• Stage 4 – The cancer has spread to nearby tissues or organs and more than one nearby lymph node contains cancer cells or the cancer has spread to other parts of the body further away.

Finding the stage of a cancer helps doctors to advise on what is the best treatment and gives them a reasonable indication of the prognosis (outlook).

Grading is used to indicate how quickly or slowly a cancer is likely to grow and spread. Cells from a sample of the cancer (a biopsy) are looked at under the microscope or tested in other ways.

By looking at certain features of the cells the cancer can be graded as low, intermediate, or high grade; this system is called the Fuhrman system:

• Grade 1 or low-grade cells are usually slow growing, look quite similar to normal cells, tend to be less aggressive and are less likely to spread.
• Grade 2 or intermediate grade cells grow more quickly, look abnormal, are moderately aggressive and could spread.
• Grade 3 or high-grade cells are likely to grow more quickly, look very abnormal, tend to be more aggressive and are more likely to spread.
• Grade 4 or high-grade cells look very abnormal, grow very quickly, are extremely aggressive and are very likely to spread.

Can kidney cancer be detected early?

In many cases, there are no obvious symptoms at first and kidney cancer may only be found during tests for another condition or reason. You may notice that your urine is darker than usual or reddish in colour and you may feel a persistent pain in your lower back or side, just below your ribs. Although it is unlikely that you have cancer, it is important to get your symptoms checked out.

How is kidney cancer diagnosed?

You should see your doctor if you notice a change that isn’t normal for you or if you have any of the possible signs and symptoms of kidney cancer identified above.

Depending on your symptoms your GP might do a general examination. They will feel for any areas that might be swollen or might not feel normal, and if you have any pain, they will feel those areas too. Most kidney cancers are too small for you or a doctor to feel. Your GP might ask you to provide a urine sample so they can test this and they might arrange for you to have blood tests. Your doctor may also arrange an ultrasound scan to check for cancer.

More than half of adult kidney tumours are detected when using an ultrasound scan to investigate symptoms such as high blood pressure, muscle wasting and weight loss, high temperature or fever, disorders affecting the nerves and muscles, inflammation, anaemia, abnormal liver function tests, and high levels of calcium in the blood (hypercalcaemia).

If you have blood in your urine, your doctor might want to refer you for a cystoscopy to check inside your bladder. The procedure is carried out under local anaesthetic or sometimes under general anaesthetic.

If the initial investigations confirm you have kidney cancer, you will need more tests to help doctors see if it has spread and how best to treat it.

These tests may include:

• CT scan – Computerised tomography (CT) is a special type of X-ray examination and is conducted in the X-ray department of the hospital. A CT scan is used to check the size of the tumour and whether it has spread to other organs, such as the lungs and the other kidney. The CT scanning machine takes a series of X-ray pictures of your body from different angles. A computer puts these images together to give a detailed image of the inside of your body. You may be given an injection of a special dye, or contrast agent, into a vein in your arm to help blood vessels show up more clearly. A CT scan is painless but takes longer than an X-ray. The length of the whole procedure depends on how many pictures are taken, but expect to be on the couch for about 30 minutes. Some people feel a little claustrophobic during a scan.
• Biopsy – Doctors can usually make a confident diagnosis from a CT scan alone. Occasionally a biopsy will also be carried out. A thin needle is put through the skin and muscle into the kidney to remove a small sample of tissue. This is then examined under a microscope to check for signs of cancer. You will need to be observed for about four to six hours after the biopsy, and may require an overnight hospital stay.
• MRI scan – Magnetic resonance imaging (MRI) is a type of scan that uses magnetism instead of X-rays to construct a detailed picture of the inside of your body. MRI is used to check the size and extent of a tumour, and to determine whether or not the cancer has spread to other organs of the body. You may be given an injection of a special dye or contrast agent into a vein to help the tumours show up more clearly on the MRI scan picture. Similar to the CT machine, the MRI machine is shaped like a long tube and you lie on a couch, which slides backwards and forwards through the hole. During the test you have to lie very still on the couch inside the tube for about 30 minutes. It is painless but very noisy and can make people feel a little claustrophobic.
• Bone scan – You might be asked to have a bone scan to see whether the cancer has spread to your bones. If so, you will be injected with a mildly radioactive material and then asked to wait for a couple of hours while it travels through the blood and collects in the bones. Areas where there is damage to the bone will show up as hot spots. These aren’t necessarily the result of cancer. If you have arthritis, for instance, this will show up on the scan.
• Chest X-ray – This may be carried out to check your general health and make sure that you are fit enough to have certain treatments or surgery. It will also be used to rule out cancer that has spread to the lungs.

Shock is one of the most common feelings experienced when first faced with a cancer diagnosis. This is a completely normal reaction which can in the short term cause a range of physical and emotional symptoms such as lack of sleep, lack of appetite, nausea and anxiety.

You may feel scared, anxious and panicky about what is going to happen and what the future holds. Speak to your doctors or contact one of the advice and support groups detailed at the end of this article, as they are there to help.

How is kidney cancer treated?

The treatment you have depends on the stage and type of kidney cancer. A team of doctors and other professionals will discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).

Your treatment will depend on a number of factors including:

• Your general health and fitness.
• The size of your cancer and where it is in the kidney.
• Whether the cancer has spread into lymph nodes close to the kidney.
• Whether your cancer has spread to another part of your body.

Your doctor will discuss your treatment, its benefits and the possible side effects with you. Surgery is the main treatment for kidney cancer that hasn’t spread to another part of your body. If the cancer is still small and has not spread beyond the kidney, surgery can often cure it. Some small, slow growing cancers may not need treatment at first. You might also have surgery for cancer that has spread (advanced cancer). There are various procedures for the surgical treatment of kidney cancer.

Surgery to remove the affected kidney (total or radical nephrectomy) or to remove the part of the kidney (partial nephrectomy) containing the tumour is usually the first thing doctors consider and it is performed with the intention to cure if the cancer is at an early stage and has not spread.

Even some more advanced cancers may be cured if all the cancer can be removed. However, removing a kidney or part of a kidney is a major operation so you need to be fit enough to cope and recover afterwards. That is why this treatment may not be possible for everyone. Surgery can also be used to remove metastases in some cases of advanced kidney cancer.

During a radical nephrectomy the whole kidney and the surrounding fatty tissue, the adrenal gland, and nearby lymph nodes are usually removed, although the extent of a radical nephrectomy can vary between patients. This is usually performed using a keyhole laparoscopic or robot assisted laparoscopic approach.

You can live perfectly well with just one working kidney, but if both kidneys are removed because of bilateral renal cell carcinoma, or because they are not working, you will need dialysis for the rest of your life or a kidney transplant.

Removing part of the kidney containing the tumour is called a partial nephrectomy or kidney/nephron sparing surgery. The aim of this surgery is to remove the whole tumour while leaving as much normal tissue as possible, aiming to preserve kidney function. It means that some working kidney is left behind. Specialist surgeons now treat most early stage (stage 1) kidney tumours that are less than 7cm in size with partial nephrectomy, if possible. This is also usually performed using a keyhole laparoscopic or robot assisted laparoscopic approach.

Ablative therapies include cryotherapy and radiofrequency ablation. These treatments are less invasive ways of treating kidney tumours. These treatments can be used to treat CT1 small tumours, less than 4cm in size, and for people who are unable to have surgery or who want to avoid surgery. They may also be used to treat people with multiple kidney tumours or tumours in both kidneys (bilateral disease).

Cryotherapy kills the cancer cells by freezing the tumour. The doctor inserts one or more fine needles or probes through the skin (percutaneous) and into the tumour. Argon gas is passed through the needles to freeze the tumour.

Cryotherapy is usually carried out under general anaesthetic. The National Institute for Health and Care Excellence (NICE) has issued guidance for percutaneous cryoablation; however, this procedure is only available at specialist centres in the UK.

Drug treatments for kidney cancer will be based on the stage and grade of your cancer and your general health.

Biological therapies are drugs which are used to kill cancer cells or stop them from growing. Biological therapies are used to try to shrink or control advanced kidney cancer and help people to live longer. You may be given biological therapies for kidney cancer that has already spread or is at high risk of coming back after surgery.

Drugs such as sunitinib (Sutent®), pazopanib (Votrient®), axitinib (Inlyta®), tivozanib (Fotivda®), and Cabozantinib (Cabometyx®) are Tyrosine Kinase Inhibitors (TKIs). These drugs block the effects of a protein called tyrosine kinase, which is involved in new blood vessel growth, essential for cancer cells to divide and grow. These treatments starve the tumour by stopping the development of a new blood supply (angiogenesis).

These types of medications are called anti-angiogenic agents. Tyrosine kinase inhibitors also interfere with the growth of cancer cells by blocking the signals within the cancer cells that tell them to grow and divide, causing the cancer cells to die. Tyrosine kinase inhibitors come as tablets or capsules taken orally.

The immunotherapy interleukin-2 used to be the main treatment for advanced kidney cancer. This approach stimulates the body’s own immune system to attack the cancer cells. It uses man-made copies of substances found naturally in the body. However, its use has been superseded by targeted therapies and monoclonal antibodies, which are more effective at controlling the cancer and have less severe side effects.

Radiotherapy uses high energy X-rays to destroy cancer cells. For patients who are unable to have surgery, it can be used to shrink a kidney cancer and so control symptoms. It can also be used if the cancer has spread to other areas of the body, such as the brain, lungs, liver or bone, or for the treatment of cancer that has come back (recurred).

Chemotherapy isn’t generally used for renal cell cancer. This is the most common type of kidney cancer. You might have it if you have transitional cell cancer of the kidney. Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. It is more common to have chemotherapy for a type of kidney cancer called transitional cell cancer. This can grow in the kidney, bladder or the connecting tubes of the urinary system (the ureters).

You have chemotherapy into your bloodstream or as tablets or capsules. You usually have treatment into your bloodstream at the cancer day clinic. For some types of chemotherapy, you have to stay in a hospital ward. This could be overnight or for a couple of days.

A patient whose kidney cancer is confined to the kidney and has not spread into the lymph nodes or to other organs of the body, statistically stands the best chance of long-term survival. Regular check-ups are essential for all kidney cancer patients, including those who, after surgery, are apparently free of disease.

Kidney cancer patients should be encouraged to be physically active before, during and after treatments, except for some temporary limitations after surgery. Physical activity during and after treatment has been shown to decrease anxiety, depression and fatigue, while improving physical function, and health-related quality of life.

Physical activity helps prevent frailty by keeping bones and muscles strong for good mobility, as well as proper heart and lung function. Physical activity also helps to control other health issues such as obesity, diabetes and high blood pressure, all of which can affect the kidneys.

Final thoughts

Living with kidney cancer can be challenging in many ways. However, following surgery, it is perfectly possible to lead a completely normal life with only one kidney, but it is important to look after your remaining kidney throughout your life.

There are some very simple measures that can be taken to monitor that your one kidney is working well. This will include an annual blood pressure check and urine test to look at how well the kidney is filtering waste from the body. You have to stick to a special diet that is low in protein, salt and potassium. You also have to keep a very close check on your fluid intake.

There are many organisations that can provide help and support if you or someone that you know has been diagnosed with kidney cancer.

This support can reduce the stress of dealing with your care, and includes:

• Kidney Cancer UK 0800 002 9002.
• Macmillan Cancer Support 0808 808 00 00.
• Action Kidney Cancer 0800 121 8721.
• Children’s Cancer and Leukaemia Group 0333 050 7654.
• Bethany’s Wish 0247 767 2030.