“Kidney cancer” covers a number of different tumour types. The most common kidney cancer type is clear cell renal cell carcinoma (often referred to as ccRCC). There are a variety of other less common kidney cancers including papillary renal cell carcinoma (types I and II), chromophobe renal cell carcinoma and others. There are also a variety of benign (non-cancerous) kidney tumours such as angiomyolipomas (AMLs), oncocytomas and others which often have to be differentiated from cancerous tumours.
The majority of kidney cancers diagnosed these days are as an incidental finding on an imaging study being performed for other reasons.
Imaging is the mainstay of kidney cancer diagnosis. This commonly involves ultrasound of the kidney and a CT scan (CT IVP). Occasionally a biopsy of the mass may be recommended to help diagnosis.
These different cancers can demonstrate a spectrum of behaviour from indolent (slow-growing and not immediately problematic), to very aggressive.
Localised kidney cancer is very curable; however, once a tumour has spread to other parts of the body, it is generally considered incurable. Depending on the type, size, location, age and general health of the patient and other factors, different treatment options exist.
Small renal mass
Small renal mass (SRM) is the term used to generally describe a kidney mass identified on imaging studies under the size of 4cm diameter. A majority of these will be small kidney cancers, however a proportion will be benign. The standard management for many of these tumours is an active surveillance protocol. This is very similar to the concept used in low risk prostate cancer and involves repeat imaging to determine the behaviour and growth of the mass, but not “miss the boat”.
Many of these will grow very slowly or not at all; however, should a mass grow more rapidly it may indicate a more aggressive behaviour and generally would trigger definitive treatment. Generally, the risk of spread of a kidney cancer <4cm in size is very small, and it is very safe to monitor in this way. In some older patients or those who are unfit for surgery due to other medical conditions, a watchful waiting protocol (again similar in concept to that used in prostate cancer) is used to monitor the patient but without a planned option to jump in and treat the tumour even if it behaves more aggressively.
If a tumour is larger than 4cm and/or demonstrating more aggressive features and the patient is fit, definitive treatment is generally recommended. The gold standard for management is surgery. This is performed as either a partial nephrectomy (removal of the mass but leaving the majority of the normal kidney behind) or radical nephrectomy (removal of the entire kidney). This surgery can be performed as an open operation, or minimal invasive (keyhole) surgery either as laparoscopic or robotic assisted.
Alternatives to surgery include tumour ablation via various different technologies e.g. Stereotactic Body Radiation Therapy (SBRT), Cryotherapy or Radiofrequency Ablation (RFA). While these are less invasive, they are generally considered secondary options for patients unfit for major surgery.
A/Prof Vela will discuss with you his recommended approach and why this is recommended in your individual case.
If a kidney cancer spreads outside of the kidney, various systemic or localised therapies may be recommended. This again depends on the type of tumour, the location and degree of tumour spread and the general fitness of the patient. In this setting A/Prof Vela will often involve other specialist team members from medical oncology and in some cases radiation oncology.
These tumours are much less common than the previously discussed cancers. A/Prof Vela has extensive training in treating all genitourinary cancer types including rare cancers such as these.