The kidneys are two bean-shaped organs located on either side of the body, just underneath the ribcage. The main role of the kidneys is to filter out waste products from the blood and to produce urine.
Kidney cancer is the 6th most common cancer in Australian men and the 11th most common cancer in Australian women. Kidney tumours are usually found by chance when ultrasounds or CT scans are ordered to look for other disorders in the abdomen. Less commonly, they may cause blood in the urine, a lump that can be felt in the abdomen or abdominal pain. Kidney cancer usually affects only one kidney.
There are two broad types of kidney tumours;
- Renal Cell Carcinoma arises from the kidney tissue and account for about 85% of kidney tumours. These tumours are more common in people who are overweight and who smoke.
- Urothelial (Transitional Cell) Carcinoma arises in the drainage component of the kidney (the collecting system) and ureter tube. These tumours are more common in people who smoke, have a history of using a pain-killer called phenacetin (now banned) or who have worked with certain chemicals or dyes.
Other tumour types are rare, including sarcoma, lymphoma and metastastic deposits of other cancers.
When a kidney tumour is suspected a CT scan with contrast (dye injected into a vein) is most commonly used to visualize the area. Sometimes an ultrasound or MRI scan are used to get more detailed images.
If a Urothelial Carcinoma is suspected a series of urine tests to look for atypical cells (urine cytology) and an ureteroscopy (passage of a telescope into ureter tube and kidney) may be required to confirm the diagnosis.
A CT scan of the chest is used to rule out spread of cancer to the lungs. A bone scan may be ordered to rule out disease in the bones. A DMSA or MAG3 scan may be used to assess the function of each kidney prior to surgery.
Occasionally, if a diagnosis cannot be made with imaging it may be necessary to take a biopsy of the kidney under CT or ultra-sound guidance.
The primary form of treatment for most kidney cancers is surgery. The surgery required depends on the tumour type, size and where it is located in the kidney.
For a very small tumour it may be possible to safely observe it over time. Small tumours that grow very slowly or do not change in size can be monitored with CT or ultrasound scans. By closely following these lesions it is possible to avoid surgery in some cases, but still identify when a tumour poses a risk and requires treatment.
For small kidney tumours (usually less than 4cm) is it sometimes possible to remove only the affected portion of the kidney. This allows for remaining, healthy kidney tissue to be preserved. The suitability of a tumour for partial nephrectomy depends on the location of the lesion in the kidney and how the patient’s other kidney functions.
- Open Partial Nephrectomy: An incision if made through the flank to allow access to the kidney. The kidney mass is removed and the normal tissue is preserved. A hospital stay of about 5 days is typical after this operation.
- Robotic Partial Nephrectomy: The diseased portion of kidney is removed with keyhole surgery and the utilization of a surgical robot to allow for very precise and safe dissection. Recovery time is much shorter using keyhole surgery; it requires a hospital stay of 2-3 days.
The whole kidney, adrenal gland and the surrounding fatty tissue are removed. This is the most common treatment for kidney cancer.
- Laparoscopic or robotic nephrectomy: Keyhole surgery is used to remove the whole kidney and surrounding tissue. A larger incision (approximately 10cm) is made in the lower abdomen at the end of the operation, through which the kidney is removed in a specially designed bag. Typically this procedure would require a hospital stay of 2-3 nights.
- Open nephrectomy: For very large tumours or tumours with extension into the renal vein or inferior vena cava (large abdominal veins) it may be necessary to perform an open operation. If there is extensive involvement of the veins a team of other surgeons may be involved, including a second urologist, a liver surgeon and a vascular surgeon.
For Urothelial Carcinomas it is necessary to remove the whole kidney and the attached ureter tube, all the way down to the connection with the bladder. This operation is usually performed with keyhole surgery, but may require an incision over the bladder to complete the removal of the ureter. Because the ureter tube is detached from the bladder is it usually necessary to leave a urinary catheter to drain the bladder for several days to allow the bladder stitches to heal.
Radio-Frequency Ablation (RFA):
For patients who are not well enough for an operation who have a small tumour (less than 4cm) it may be possible to use RFA. This procedure is performed by the radiology doctors, who pass needles through the back to deliver high intensity energy to the kidney tumour. This process destroys the cancer cells and causes the tumour to scar.
There are a number of medications that have been developed in recent years to treat kidney cancers that have spread beyond the kidney and are not suitable for surgery. These medications block certain cellular pathways to stop or slow cancer growth. If investigations show that the kidney cancer has spread beyond the kidney, your Urologist will refer you to a Medical Oncology doctor to discuss other treatment options.