An Introduction to Kidney Cancer Treatment
Kidney cancer, the most common type of which is renal cell carcinoma (RCC), is a disease where the treatment approach is overwhelmingly guided by the stage of the cancer at diagnosis. A treatment plan is developed after a careful evaluation of the tumor’s size, its location within the kidney, and whether it has spread beyond the kidney to nearby lymph nodes or distant organs. The patient’s age, overall health, and existing kidney function are also critical factors.
For the majority of patients who are diagnosed with localized kidney cancer (cancer that is confined to the kidney), the goal of treatment is curative, with a strong emphasis on surgical removal of the tumor. For patients with advanced or metastatic disease, where the cancer has spread, the treatment goals shift to controlling the cancer’s growth, managing symptoms, and prolonging life using systemic medications.
The Role of the Multidisciplinary Team
The management of kidney cancer, particularly advanced disease, benefits from the collaboration of a multidisciplinary team (MDT). This team of specialists works together to provide a comprehensive and coordinated treatment plan tailored to the individual patient.
A typical kidney cancer MDT includes:
- Urologic Oncologist or Urologist: A surgeon who specializes in the urinary tract system and is typically the primary physician for diagnosing and surgically treating kidney cancer.
- Medical Oncologist: A physician who manages systemic therapies, such as targeted therapy and immunotherapy, which are the cornerstones of treatment for advanced kidney cancer.
- Interventional Radiologist: A physician who performs minimally invasive procedures, such as tumor ablation or embolization.
- Radiation Oncologist: A doctor who specializes in using radiation therapy, which can be used in specific situations to treat kidney cancer.
- Pathologist: A physician who examines the removed tumor tissue to confirm its type, subtype, and grade (how aggressive it appears).
- Radiologist: A physician who interprets imaging scans like CT and MRI to help stage the cancer and monitor treatment response.
Treatment for Localized Kidney Cancer (Stages I, II, and III)
For kidney cancer that has not spread to distant parts of the body, surgery is the standard of care and offers the best chance for a cure. The main goal of surgery is to completely remove the tumor.
Surgical Treatment
The choice of surgical procedure depends primarily on the tumor’s size, location, and complexity.
- Partial Nephrectomy: This is the preferred surgical approach for most tumors, especially those that are smaller (typically less than 7 cm). In this procedure, the surgeon removes only the tumor along with a small margin of surrounding healthy kidney tissue, leaving the rest of the kidney intact. The major advantage of this approach is the preservation of kidney function, which is important for long-term health and can reduce the risk of developing chronic kidney disease later in life. A partial nephrectomy can be performed using an open incision, or more commonly, through minimally invasive laparoscopic or robotic-assisted techniques.
- Radical Nephrectomy: This procedure involves the removal of the entire kidney, the attached adrenal gland, and the fatty tissue surrounding the kidney. A radical nephrectomy is typically recommended for very large tumors, tumors that are centrally located and not amenable to a partial nephrectomy, or tumors that have grown into nearby blood vessels. As long as the remaining kidney is healthy, a person can live a normal, healthy life with just one functioning kidney.
In some cases of Stage III disease, where the tumor has grown into the main renal vein or the large vein leading to the heart (the vena cava), the surgery becomes much more complex and may require the expertise of a cardiothoracic surgeon in addition to the urologic oncologist.
Active Surveillance
For some very small kidney tumors (typically less than 3-4 cm), particularly in older patients or those with significant other health problems, a period of active surveillance may be recommended. This involves closely monitoring the tumor with regular imaging scans (like CT or ultrasound) to track its growth rate. The rationale is that many small kidney tumors are slow-growing and may never pose a threat to the patient’s health, so the risks of surgery may outweigh the benefits. If the tumor shows signs of significant growth, treatment can then be initiated.
Local Therapies for Small Kidney Tumors
For patients with small tumors who are not good candidates for surgery due to age or other medical conditions, minimally invasive local therapies can be used to destroy the tumor without surgically removing it. These are performed by an interventional radiologist.
- Cryoablation: A probe is inserted through the skin and into the tumor under image guidance. The probe then circulates extremely cold gases to create an “ice ball” that freezes and destroys the cancerous tissue.
- Radiofrequency Ablation (RFA): Similar to cryoablation, a probe is inserted into the tumor. It then emits a high-frequency electrical current that generates heat, effectively “cooking” and destroying the tumor cells.
Ablation therapies are generally most effective for smaller tumors (less than 3-4 cm) and are considered a less invasive alternative to surgery, though they may have a slightly higher risk of local recurrence compared to surgical removal.
Treatment for Advanced or Metastatic Kidney Cancer (Stage IV)
When kidney cancer has spread to distant lymph nodes or other organs (most commonly the lungs), it is known as metastatic or Stage IV disease. At this stage, surgery on the primary kidney tumor is not curative, and the cornerstone of treatment is systemic therapy—medications that travel through the bloodstream to treat cancer throughout the body.
Traditional chemotherapy is not effective against renal cell carcinoma. Instead, treatment has been revolutionized by the development of targeted therapies and immunotherapies.
Targeted Therapy
Targeted therapy drugs are designed to block specific pathways that kidney cancer cells use to grow. The most common class of drugs used for kidney cancer are those that inhibit angiogenesis—the process by which tumors create new blood vessels to get oxygen and nutrients. By blocking this process, the drugs can effectively starve the tumor. These are typically oral medications taken daily.
Immunotherapy
Immunotherapy, specifically a class of drugs called immune checkpoint inhibitors, has become a frontline standard of care for most patients with advanced kidney cancer. These drugs work by taking the “brakes” off the body’s own immune system, unleashing its T-cells to recognize and attack the cancer cells. For many patients, the most effective approach is a combination of two immunotherapy drugs or an immunotherapy drug combined with a targeted therapy drug.
The Role of Surgery and Radiation in Metastatic Disease
While systemic therapy is the main treatment, surgery and radiation still have important roles:
- Cytoreductive Nephrectomy: In some specific cases, for patients who are very fit and have had their metastatic disease respond well to initial systemic therapy, surgically removing the primary kidney tumor (a cytoreductive nephrectomy) may be considered.
- Radiation Therapy: Kidney cancer was historically considered resistant to radiation. However, modern, highly focused radiation techniques like Stereotactic Body Radiation Therapy (SBRT) can be very effective. Radiation is not used to cure the disease but is an excellent tool for palliative care—treating specific metastatic spots that are causing symptoms, such as a painful bone metastasis.
Frequently Asked Questions
1. What is the difference between a partial and a radical nephrectomy?
A partial nephrectomy is a kidney-sparing surgery where the surgeon removes only the tumor and a small margin of healthy tissue, preserving the rest of the kidney. A radical nephrectomy is the removal of the entire kidney. A partial nephrectomy is the preferred option when possible, as it helps preserve overall kidney function.
2. Why isn’t chemotherapy used for kidney cancer?
Renal cell carcinoma, the most common type of kidney cancer, is known to be highly resistant to the effects of traditional cytotoxic chemotherapy drugs. For this reason, chemotherapy is not a part of the standard treatment for kidney cancer. Instead, treatment relies on the much more effective systemic options of targeted therapy and immunotherapy.
3. What is active surveillance for kidney cancer?
Active surveillance is a strategy of closely monitoring a small kidney tumor with regular imaging scans (like CT or ultrasound) instead of proceeding immediately with surgery or another treatment. It is an option for older patients or those with other health issues who have small, slow-growing tumors, where the risks of intervention might outweigh the benefits.
4. How does immunotherapy work for kidney cancer?
Immunotherapy drugs called immune checkpoint inhibitors work by blocking proteins that cancer cells use to “hide” from the immune system. By blocking these signals, the drugs essentially take the brakes off the immune system’s T-cells, allowing them to recognize the cancer cells as foreign and launch an attack against them.
5. What is the goal of a partial nephrectomy?
The primary goal of a partial nephrectomy is to cure the cancer by completely removing the tumor. A critical secondary goal is to preserve as much healthy, functioning kidney tissue as possible. This helps to prevent the long-term development of chronic kidney disease, which can have its own health consequences.
6. Can a person live a normal life with only one kidney?
Yes. A healthy person can live a completely normal and healthy life with a single functioning kidney. The remaining kidney will compensate and is able to adequately filter waste from the body. This is why a radical nephrectomy is a safe and standard procedure.
7. When is ablation used instead of surgery for a kidney tumor?
Ablation (either freezing or heating the tumor) is typically considered for patients with small kidney tumors who are not good candidates for surgery. This may be due to advanced age, poor overall health, or poor kidney function that would be further compromised by surgery. It is a less invasive option, though it may not have as high a cure rate as surgical removal.
