What is Metastatic Kidney Cancer
Metastatic kidney cancer, also known as stage 4 renal cell carcinoma, occurs when cancer originating in the kidneys spreads to other parts of the body. Kidney cancer begins in the lining of the renal tubules, responsible for filtering waste products from the blood. When these cancer cells break away and travel through the bloodstream or lymphatic system, they can form new tumours in distant organs. Common sites for metastasis include the lungs, bones, liver, and brain.
Causes of Metastatic Kidney Cancer
The exact cause of metastatic kidney cancer, like many cancers, remains largely unclear. Several risk factors are known to increase the likelihood of developing kidney cancer, which may eventually lead to its metastatic form.
- Smoking and Lifestyle Factors: Smoking can increase the risk, alongside factors like obesity and hypertension.
- Genetic Conditions: Genetic disorders such as von Hippel-Lindau disease and hereditary papillary renal cell carcinoma can heighten the risk.
- Long-term Dialysis: Extended dialysis treatment can increase the likelihood of developing kidney cancer.
- Exposure to Harmful Substances: Contact with certain chemicals, such as asbestos and cadmium, is linked to a higher risk.
- Previous Cancer Treatments: Treatments for other cancers, especially testicular or cervical cancer, can also contribute to the risk.
Symptoms of Metastatic Kidney Cancer
In its early stages, kidney cancer may not exhibit noticeable symptoms. As the disease progresses to a metastatic stage, symptoms become more apparent and vary depending on the location of metastases. This includes:
- Bloody Urine: This is a common early symptom, indicating potential kidney involvement.
- Persistent Back Pain: Often occurs due to the tumour’s growth or pressure on surrounding areas.
- Unexplained Weight Loss and Fatigue: These are general symptoms that accompany many types of cancer.
- Respiratory Symptoms: This Includes persistent cough or shortness of breath, especially if the cancer has spread to the lungs.
- Bone Pain or Fractures: These symptoms are indicative of bone metastases.
- Neurological Symptoms: Such as headaches or changes in vision, possibly signalling brain metastases.
These symptoms warrant immediate medical attention for further investigation and appropriate management.
Survival Rates and Prognosis
The prognosis for metastatic kidney cancer varies based on several factors, including the patient’s overall health, the extent of metastasis, and response to treatment. Generally, the survival rate is lower for metastatic kidney cancer compared to localised kidney cancer. According to the American Cancer Society, the five-year relative survival rate for distant (metastatic) kidney cancer is approximately 14%. These statistics are averages and outcomes vary depending on the individual. Advances in treatment have improved survival rates in recent years.
Treatment Options for Metastatic Kidney Cancer
Systemic Therapy
Systemic therapy for metastatic kidney cancer involves medications that work throughout the body. These drugs are designed to target cancer cells or the mechanisms that support their growth. The most common systemic treatments include immunotherapy and targeted therapy.
- Immunotherapy: This enhances the body’s immune response against cancer cells.
- Targeted Therapy: This focuses on specific molecular targets associated with kidney cancer.
The choice of systemic therapy depends on various factors, including the genetic makeup of the cancer and the patient’s overall health.
Radiation Therapy
Radiation therapy, while not a primary treatment for kidney cancer, plays a role in palliative care. It can help manage pain and other symptoms caused by metastases, such as bone metastases. High-energy beams are directed at the cancer cells to destroy them or slow their growth. This approach can be particularly effective in providing relief from pain, reducing the size of tumours, and improving the quality of life for patients with advanced kidney cancer.
Surgery (Nephrectomy)
Surgery, specifically nephrectomy, involves the removal of the kidney and is a common treatment for localised kidney cancer. In the context of metastatic kidney cancer, surgery may be used to remove the primary tumour to alleviate symptoms or to improve the effectiveness of other treatments. There are two main types of nephrectomy:
- Partial Nephrectomy: Only the cancerous part of the kidney is removed.
- Radical Nephrectomy: The entire kidney, along with surrounding tissues, is removed.
The decision to use surgery in metastatic cases is based on several factors, including the patient’s overall health and the extent of the disease.
Drug Therapy
Drug therapy for metastatic kidney cancer includes various medications that can slow the progression of the disease and manage symptoms. While traditional chemotherapy is less commonly used for kidney cancer compared to other cancers, it may be considered in certain cases. The drugs used in chemotherapy can be administered orally or through intravenous infusion and work by targeting rapidly dividing cells, including cancer cells.
Immunotherapies
Immunotherapies are increasingly used to treat metastatic kidney cancer. These therapies stimulate the body’s immune system to better recognize and attack cancer cells. Examples include checkpoint inhibitors that block proteins in cancer cells, allowing immune cells to attack them more effectively. Immunotherapies can be used alone or in combination with other treatments and have been shown to improve survival rates in some patients with advanced kidney cancer.
Targeted Therapy
Targeted therapies are drugs that specifically target the molecular changes that drive the growth and spread of kidney cancer. These medications can block the growth and spread of cancer by interfering with specific molecules involved in tumour growth and progression. Two types of drugs are primarily used in targeted therapy:
- Angiogenesis inhibitors: These prevent new blood vessel formation, which is needed for tumour growth.
- Kinase inhibitors: These block the enzymes involved in cancer cell division.
Targeted therapies have shown effectiveness in treating metastatic kidney cancer, especially in patients with specific genetic mutations.
Conclusion
Metastatic kidney cancer presents challenges in treatment and management. Understanding the nature of the disease, its symptoms, and the factors influencing its progression can aid in the early detection and treatment of the condition. While the prognosis for metastatic kidney cancer varies, advances in treatment options, including systemic therapy, radiation, surgery, and innovative approaches like immunotherapy and targeted therapy, have improved survival rates and quality of life. Personalised treatment for metastatic kidney cancer if necessary, as each patient with the condition will have different needs and circumstances.