Treatment of kidney cancer

Author : Bhadresh Bundela

A localised renal carcinoma is always considered for surgical removal; the whole kidney is removed (nephrectomy) so long as the other kidney is functioning normally and can take over the body’s overall renal function. If the tumour is localised to the kidney then such surgery may alone result in a 67% cure rate. The use of adjuvant systemic therapy (e.g. immunotherapy – vide infra) after the operation to try to reduce the subsequent incidence of relapse has not been proven and is not standard therapy. There may be a case for nephrectomy even if there is evidence of metastatic disease; some evidence having been assembled to suggest that, particularly lung, metastatic disease may be more likely to respond to other therapy (even to rarely involute without further therapy) if the large mass of primary tumour in the kidney is removed.

For metastatic spread, the options are limited as chemotherapy has a poor track record in this disease. However, in recent years, immunotherapy with interferon in particular has had some success with response rates of 15-20% in metastatic disease; the response of lung metastatic disease exceeds that of bone disease; the addition of interleukin probably impoves the response rate of interferon alone.

In the last few years, and coming with the realisation of the common involvement of the VHL gene, has come great interest in the therapeutic use of agents that inhibit VEGF and some of the cell growth promoting factors that are usually under the inhibitory control of the VHL gene. Thus, bevacizumab and sorafinib are two such medical therapies that are to some extent competing with interferon and interleukin for first place systemic therapy in this disease. It has been known for many years that this type of cancer can behave in an unusual manner – often long periods of inactivity and the patients continuing to look well and maintain weight when the tumour burden is sufficiently large that would be dragging down the health of, say, a lung cancer patient.

If immunotherapy or Sorafinib-like-drugs do not work, or when the patient relapses after such therapy, there is little that alters the natural history of the disease further.

Following the observation that oestrogens could promote the incidence of renal carcinoma in hamsters, it was usual to prescribe hormonal therapy (particularly progestogens) in therapy of metastatic disease and it is true that occasional responses have been well documented following this approach. However, it is a rare and poorly maintained response for the most part.

Occasionally, radiotherapy to the flank/loin after surgery is employed if the cancer is particularly aggressive in the flank region but it has not been shown to alter the survival statistics significantly. Local radiotherapy for painful bony metastases or for brain metastases is good for the immediate problem that they bring but do not treat the problem as a whole.

Outcomes of kidney cancer

Surgical nephrectomy stands a good chance of cure for localised disease but the disease is ultimately fatal if metastatic at presentation. Nevertheless, prolongation of life for patients who have relapsed after removal of their kidney for cancer (or for patients who present with inoperable or metastatic disease) is possible with immunotherapy and/or sorafinib/bevacizumab are the currently most successful.