Kidney Cancer

The kidneys are two bean-shaped organs that filter waste from the blood to make urine and help control blood pressure and other body functions. Kidney cancer occurs when cells in a kidney grow in an uncontrolled way and form a tumour.

The most common form in adults is renal cell carcinoma, which begins in the lining of the tiny tubes inside the kidney. Less common types include cancer that starts in the area where urine collects, and Wilms tumour, which mainly affects young children. Most people with kidney cancer have a tumour in one kidney only.

When kidney cancer is found early, while it is still contained within the kidney, it can often be treated successfully. As with other cancers, it can spread to nearby tissues or to other parts of the body if it is not treated.

In its early stages kidney cancer often causes no symptoms, and many cases are discovered by chance during scans carried out for another reason. When symptoms do occur, the most common is blood in the urine, which may make the urine look pink, red or brown. Blood in the urine should always be checked by a doctor, even if it happens only once and there is no pain.

Other possible symptoms include a persistent pain or a lump in the side or lower back, a high temperature, night sweats, tiredness, loss of appetite and unexplained weight loss. These symptoms can be caused by many conditions other than cancer, but it is important to have them assessed.

The exact cause of kidney cancer is often not known, but several factors increase the risk. Smoking is an important risk factor, as is being significantly overweight and having high blood pressure.

Other factors include increasing age, a family history of kidney cancer, certain inherited conditions, long-term kidney disease requiring dialysis, and exposure to some chemicals in the workplace. Having one or more risk factors does not mean a person will develop kidney cancer, and some people with the disease have no clear risk factors.

If kidney cancer is suspected, a doctor will ask about symptoms, examine you and arrange tests. Urine and blood tests may be done to check kidney function and look for blood or other signs. Imaging is central to diagnosis: an ultrasound scan, and often a CT or MRI scan, can show a tumour and how large it is.

Scans also help show whether the cancer has spread beyond the kidney, which guides treatment. In some cases a biopsy is taken, where a small sample of tissue is removed with a needle and examined under a microscope to confirm the diagnosis and the type of cancer. The findings are used to stage the cancer, describing its size and how far it has spread.

Treatment depends on the type and stage of the cancer, where it is, and your general health. Surgery is the main treatment, particularly when the cancer is found early and is contained within the kidney. Depending on the size and position of the tumour, a surgeon may remove just the part of the kidney containing the cancer, or the whole affected kidney. A person can usually live normally with one healthy kidney.

For small tumours, or when surgery is not suitable, other approaches may be used to destroy the cancer, such as treatments that freeze or heat the tumour. Sometimes a small, slow-growing tumour is monitored closely rather than treated straight away, especially in older people or those with other health problems.

If the cancer has spread or comes back, additional treatments may be recommended. These can include targeted therapies that interfere with how cancer cells grow and immunotherapy that helps the immune system attack the cancer. Radiotherapy may be used to relieve symptoms in certain situations. The care team will explain which options are appropriate for you.

Kidney cancer cannot always be prevented, but you can reduce your risk by not smoking, keeping to a healthy weight, and managing high blood pressure with the help of your doctor. These steps also benefit your general and heart health.

The outlook depends largely on the type of cancer and how early it is found. When kidney cancer is detected while it is still contained within the kidney, treatment is often successful. This is why it is so important to have blood in the urine, or other persistent symptoms, checked promptly rather than waiting. Your care team can explain what your particular diagnosis means and what follow-up will involve.