There are over 6,600 people diagnosed with kidney cancer in the UK each year. For unknown reasons, kidney cancer affects more men than women and 2 out of 3 people diagnosed are over the age of 65. We asked urologist Mr Christopher Anderson about kidney cancer, how it starts and how it can be detected.
All cancers start in cells, the building blocks of life that make up tissues. Tissues, in turn, make up our bodily organs. Normally when cells get old they die and cells grow and divide to make new cells all the time for our bodies to use when needed. Cancer develops when old cells don’t die and new cells are created when the body doesn’t need them, so a huge mass of extra cells develops and becomes a growth or a tumour. These can be benign (non-cancerous) or malignant (cancerous).
Are there different types of kidney cancer?
There are several types of kidney cancer, most of which are renal cell cancer or renal cell carcinoma, which can be divided into different sub-types. The majority of renal cancers are “ clear cell ” renal cell cancer. Some cancers are derived from transitional cells that line the renal pelvis, ureter and bladder. Occasionally rare subtypes like sarcomatoid renal cell cancer are found: these tend to spread more quickly and are more likely to spread to other parts of the body.
The majority of kidney cancers are localised to the kidney or spread to adjacent tissue nearby (locally-advanced). These two make up 70% of patients and the remaining 30% of patients present with metastases, where the cancer has spread outside of the kidney to other parts of the body.
Does kidney cancer have symptoms?
In its early stages, kidney cancer usually shows no signs or symptoms. This is why up to 80% of kidney cancers are discovered by accident on scans done for other health reasons.
As a kidney tumour grows, however, symptoms such as the following might occur:
- A lump in the kidney area
- Pain in the side
- Blood in the urine, which might cause urine discolouration, or the amount of blood might be so small that it is only detected under a microscope or with dipstick testing.
Less common symptoms include:
- Weight loss
- Loss of appetite
- High blood pressure. If the cancer interferes with the blood supply to the kidney, an enzyme called renin is released, which leads to an increase in blood pressure
- Anaemia; which is a result of lower than normal red blood cells in the blood
- An abnormally high red blood count; resulting in polycythaemia.
- Hypercalcemia; high levels of calcium in the blood
- Varicocele in the scrotum (dilated veins in the scrotum)
How is kidney cancer diagnosed?
The standard scan to diagnose kidney tumours is the CT scan. If a CT scan isn’t used, an MRI scan is an alternative. Sometimes an ultrasound or intravenous urography might be done initially, but a CT or MRI will always be needed to get a picture of the kidney in detail and to see the exact position of the tumour.
If cancer is suspected to have spread beyond the kidney, a bone scan can be carried out to check if cancer has spread to the bones. A renogram might also be performed if more information is needed about the function of the kidneys.
If you’ve been diagnosed with kidney cancer or would like more information visit Mr Christopher Anderson on his Top Doctors profile.