Surgery to treat kidney cancer is called nephrectomy. Depending on the tumor size, location and stage, the surgical oncologist may choose to remove the entire kidney (radical nephrectomy) or just the portion affected by cancer (partial nephrectomy).
For advanced or metastatic kidney cancer, surgery can play a role along with other treatments.
Radical nephrectomy involves removal of the entire kidney. There are two types of radical nephrectomy:
Standard or "open" surgery: a four- to five-inch incision is made in the lower back. The surgeon removes the entire kidney through the incision.
Laparoscopic Radical Nephrectomy (LRN): a small incision is made to insert a laparoscope, a thin tube with a camera that allows the surgeon to view the treatment field on a monitor. Other tiny incisions are made for miniature surgical instruments to remove the kidney. Its benefits include a shorter hospital stay (three days vs. one week), shorter recovery time and less blood loss than with open surgery.
In a partial nephrectomy, only the cancerous portion of the kidney is removed, along with a margin of healthy tissue. Pre-treatment imaging is used to determine what will be removed, and ultrasound is used to look for additional tumors during surgery.
As with radical nephrectomy, this procedure can be done by traditional or laparoscopic methods. Laparoscopic partial nephrectomy (LPN) is still considered developmental.
Candidates for partial nephrectomy are chosen based on favorable tumorlocation, co-existing health problems that may affect the treatment outcome and the patient's desire to save their kidney. Partial nephrectomy is best for tumors four centimeters or less in size. Recurrence rates for both types of partial nephrectomy are about 5%.
Energy Ablative Techniques
Another minimally invasive surgery technique uses either heat or cold energy to treat tumors in place, without having to remove the kidney.
Cryoablation freezes the tumor to -150 degrees Centigrade with a long, thin probe inserted into the tumor. Intensive follow-up with X-rays or other imaging procedures is required to ensure that the tumorhas been destroyed. Cryoablation is ideal for smaller kidney tumors in patients considered at high risk for surgery.
Radiofrequency Ablation (RFA) is similar to cryoablation, but heat is used to kill the tumor instead of cold. RFA does have good potential for appropriate patients.
Radiation has a limited role in the treatment of kidney cancer. Kidney tumors are not very sensitive to radiation, but healthy kidneys are, so radiation as a frontline treatment isnot viable.
In some cases, radiation may be used as a palliative treatment, to ease pain and other symptoms of advanced kidney cancer that has spread to bone or other areas of the body.
Chemotherapy is generally ineffective against kidney tumors, but may have a role in the treatment of metastatic tumors that have spread to the lung, bones, brain or lymph nodes. In these cases, chemotherapy would be combined with surgery or other localized therapy. A combination of gemcitabine and capecitabine to treat metastatic renal cell carcinoma has been studied in several clinical trials, and other chemotherapy agents may also be analyzed for their effectiveness in treating metastases.
A significant amount of cancer research has been devoted to immunotherapy, which uses the body's own defense mechanisms to fight cancer. All cells have protein markers, called antigens, on their surfaces that identify them as either "normal" or "foreign." The presence of foreign antigens (such as cancer cells) provokes a sophisticated chemical reaction involving lymphocytes and other cells that defend the body against disease. Some of these defender cells produce antibodies, which seek out and destroy specific antigens.
Immunotherapies are designed to manipulate the antigen/antibodyimmune response by targeting antigens on specific types of tumor cells. As researchers identify more of these tumor-specific antigens, they are working to develop therapeutic agents that target only those cells.
There are two basic types of immunotherapy:
Antibody therapy targets specific antigens. Rituximab and Herceptin are examples of antibody therapies currently approved for treatment of certain types of lymphoma and breast cancer, respectively.
Cancer vaccines are designed to attack antigens that exist specifically on cancer cells. However, many of these proteins are also expressed on normal cells. MD Anderson researchers are trying to re-teach the immune system to recognize and eliminate tumor antigens without affecting normal cells.
Immunotherapy & Kidney Cancer
Renal cell carcinoma (RCC) is very responsive to immunotherapy, which has become the standard of care for metastatic disease. Two types of immunotherapy are used to treat metastatic RCC:
Interferon-alpha is a protein produced by white blood cells in response to a viral infection. It increases antigens on the surface of cancer cells, making them more susceptible to attack by the immune system. Interferon is an outpatient treatment administered via injection, which patients can do themselves. Side effects of interferon therapy include flu-like symptoms (fever, muscle aches, headache and nasal congestion), depression, fatigue and nausea.
Interleukin-2 (IL-2) is a protein that stimulates the growth of immune cells and activates them to destroy tumor cells. High-dose IL-2 therapy is administered intravenously, and treatment requires a five-day hospital stay. Side effects include hypotension (low blood pressure), flu-like symptoms (fever, muscle aches, headache and nasal congestion), decreased urine production, nausea and diarrhea.
Both of these therapies have only a general, non-targeted effect on the immune system, and their intense side effects are not well-tolerated by many patients. Both therapies have about a 15% response rate, but those who do respond do so quite dramatically.
Kidney tumors are very vascular (blood vessel-rich). They rely on a process called angiogenesis to create their own network of blood vessels, enabling the tumor to thrive and grow. These blood vessels have unique characteristics that may make them vulnerable to drugs designed specifically to target them without harming normal blood vessels.
A number of "anti-angiogenic" compounds have been developed to take advantage of the process, including bevacizumab (AvastinTM) and sorafenib (Nexavar®). These are merely examples of a growing field of treatments that target vulnerabilities specific to the tumor, with lower side effects than traditional chemotherapies or immunotherapies.