The kidneys are essential organs that filter the blood, removing waste products through the urinary tract as urine. Like any other organ, the kidney can be affected by cancer.
Kidney cancer accounts for around 3% of all cancers diagnosed in Australia each year. The commonest form of cancer is renal cell carcinoma (RCC), which grows from cells lining the microscopic tube system within the kidney. The cancer can grow slowly over a number of years and because of the kidney’s location in the body, usually causes no symptoms until it becomes quite large. For this reason, RCC is now most often detected incidentally on scans performed for other reasons, and when found at an early stage has an excellent chance of cure with surgical removal.
A diagnosis can be made pre-operatively, through needle biopsy, however as over three-quarters of solid kidney tumours are cancerous, it is often appropriate to proceed directly to surgery and make the diagnosis on the removed specimen.
Treatment varies according to the type of tumour and the clinical circumstances:
Observation: As small tumours grow slowly and the risk of spread is extremely low (<5%) while under 4cm in size, it is not uncommon to simply monitor the growth with scans (eg every 6 months), particularly if other health problems are present that would make treatment riskier than the tumour itself. Treatment can be offered if the tumour grows more rapidly, but in fact many people, particularly elderly patients, are monitored for years without ever requiring any treatment at all.
Surgery: If treatment is required, surgery is the gold standard. Large tumours require the whole kidney to be removed (radical nephrectomy), whereas for smaller tumours the kidney can be preserved and just the cancer itself removed (partial nephrectomy).
Ablation: Depending on the size and location of the tumour, it may be possible to kill the tumour usually by passing a needle through the skin into the tumour and ablating it with heat (radiofrequency ablation). Other forms of ablation are being studied, such as high dose radiotherapy, that can avoid the need for an operation.
Laparoscopic and robotic surgery
To avoid a large incision to remove the kidney tumour, keyhole (laparoscopic) surgery has steadily replaced open surgery in most situations except where the cancer is large or advanced. Robotic surgery is a form of keyhole surgery using more sophisticated instruments and three-dimensional cameras to remove just the tumour itself, reconstructing and preserving the kidney.
A/Prof Moon has been responsible for developing these techniques, publishing the first Australian series of robotic partial nephrectomy, reporting high success rates and a low risk of complications.1
1. Kucharczyk J, Basto M, Landau A, Graves R, Everaerts W, Birch E, Murphy D and Moon D. Early experience and operative technique of robotic-assisted partial nephrectomy in Australia. ANZ J Surg
Unfortunately, kidney cancer has sometimes spread to distant sites in the body (metastasized) by the time of diagnosis. It is usually incurable at this stage, but modern systemic treatments may be given, which have shown improved survival and can control the disease for long periods of time. It is worth discussing this form of treatment with your urologist or medical oncologist (cancer specialist) as there may also be the option of involvement in clinical trials of newer drugs.