As a general rule, kidney tumors are considered surgical problems. Radiation and traditional methods of chemotherapy do not work for these cancers. Immunotherapy, and more recently, tyrosine kinase inhibition have been explored with some success for patients with disseminated disease.
Most kidney tumors may be approached using minimally invasive methods such as laparoscopy or robotics. The type of operation chosen is dependent upon a variety of factors:
- Size of the tumor
- Location of the tumor within the kidney
- Presence or absence of tumor extension to lymph nodes, adrenal gland, renal vein
- Presence or absence of tumor spread to other sites
- Overall health of the patient
- Functional status of both kidneys
- Experience and skill set of the operating surgeon
About half of all kidney tumors discovered are 4cm or less – almost all of these tumors may be treated by partial nephrectomy [and yet only 12% of kidney tumors are treated by partial nephrectomy nation wide]. Few surgeons have the demonstrated skill to perform robotic and straight-stick laparoscopic partial nephrectomy. Make certain that you see a surgeon, like Dr. Kaynan, who is facile in all the treatment options such that you may be recommended without bias to the best choice for you!
- Radical Nephrectomy (Open, Laparoscopic, or Robotic)
- Partial Nephrectomy (Open, Laparoscopic, or Robotic)
- Radical Nephroureterectomy (Open, Laparoscopic, or Robotic)
- Cryotherapy (Percutaneous or Laparoscopic)
- Radiofrequency Ablation (Percutaneous or Laparoscopic)
- IL-2 or Interferon Immunotherapy
- Targeted Therapy
Radical Nephrectomy (Open / Laparoscopic / Robotic)
This entails total removal of the kidney. It’s used primarily for large kidney tumors. The open approach is preferred for the biggest tumors, and tumors with advanced local features such as invasion into the main vein of the kidney. Most people can live just fine with only one kidney.
Partial Nephrectomy (Open / Laparoscopic / Robotic)
Patients with smaller kidney tumors (~4 cm or less), poor kidney function, tumor in a solitary kidney, or bilateral kidney tumors are candidates for partial nephrectomy. While there is a slightly higher chance of local tumor recurrence with partial nephrectomy, the chance of long-term survival from cancer is the same whether treatment is by total nephrectomy or partial nephrectomy. Overall kidney function is better preserved by partial nephrectomy, however, and overall crude survival is better with partial nephrectomy.
This surgery is much more complex than total nephrectomy because once the tumor is removed from the kidney, the kidney must be reconstructed so that it does not bleed or leak urine. The kidney has a rich blood supply, and the main vessels to the kidney often must be temporarily clamped in order to remove the tumor without excessive blood loss. During open surgery, the kidney is typically iced down in order to reduce the energy requirements of the kidney while the vessels are clamped. This safely extends the working time allowed to remove the tumor and reconstruct the kidney.
Radical Nephroureterectomy (Open / Laparoscopic / Robotic)
This surgery is directed at patients with tumors involving the urothelial lining of the inner kidney or ureter (transitional cell cancers) and entails total removal of the kidney, ureter and cuff of bladder. This may be done using open, laparoscopic or robotic methods, depending upon the specifics of the case. The benefits of laparoscopy over open surgery are the same as for radical nephrectomy (see above). Dr. Kaynan prefers a combined approach of cystoscopic incision of the bladder cuff (ie, transurethrally), followed by robotic distal ureterectomy (including excision of the bladder cuff and bladder repair), followed by hand-assisted laparoscopic kidney removal. With the advent of the Xi surgical robot, however, Dr. Kaynan is exploring the efficiency of total robotic nephroureterectomy.
Cryotherapy and Radiofrequency Ablation
These are energy ablation techniques which may be done laparoscopically or percutaneously (passing a needle through the skin to the kidney). In cryotherapy, the tumor is frozen. In radiofrequency ablation, the tumor is heated. Both methods are considered minimally invasive. However, they have demonstrably higher rates of recurrence compared to partial or total nephrectomy. These methods are generally reserved for small tumors (3 cm or less) in patients who ought not risk partial or total nephrectomy.
IL-2 and alpha-interferon are cytokine agents which stimulate the immune system to fight kidney cancer cells, used when kidney cancer has spread to other parts of the body. Surgical removal of the kidney is typically recommended, even in the setting of known tumor spread, as a means of “debulking” cancer from the body – this improves the effectiveness of immunotherapy and improves survival. The side effects from IL-2 can be quite drastic and may not be administered to patients who are particularly weak. Few patients, however, are ultimately cured with this.
For patients with disseminated kidney cancer, multiple agents have become available within the last decade, including Tyrosine Kinase Inhibitors [sunitinib (Sutent); sorafenib (Nexavar); pazaponib (Votrient); axitinib (Inlyta)]; and mTOR inhibitors [temsirolimus (Torisel); everolimus (Afinitor)]. They indirectly suppress blood vessel formation, which kidney cancer cells need in order to grow and flourish. These agents are much better tolerated than immunotherapy, though they, too, have many potential side effects. Again, surgical removal of the kidney is often recommended as a means of “debulking” cancer from the body, which improves survival time. Research protocols are available at the Carol G. Simon Cancer Center for patients at risk who wish to enroll. Ask Dr. Kaynan about this.
Radiation therapy is sometimes used to target kidney tumor when it has spread to other areas, such as the bones, as a means of palliation or to prevent bone fracture. It is ineffective as a means of controlling the primary kidney tumor, however.
Chemotherapy is generally not helpful. It is used sometimes following failure of targeted therapy. Agents include vinblastine, 5-fluorouracil, capecitabine, and gemcitabine.