Introduction:
Kidneys are the primary master organs involved in the body’s excretion. The blood does not get filtered if there is any damage to these organs. The kidneys control some of the body's vital functions, like excretion, blood pressure regulation, electrolyte balance, and red blood cell production. Like all the other organs, the kidneys are prone to a number of diseases, the most common ones being chronic kidney disease (CKD) and kidney stones. Likewise, kidneys also show cancerous changes and exhibit several symptoms. Read this article to know more about the causes, symptoms, diagnosis, and treatment of kidney cancer.
What Is Metastatic Renal Carcinoma?
Renal carcinoma is the medical term for kidney cancer. The term metastatic renal carcinoma is used if these cancer cells spread to the surrounding and distant organs. Kidney cancer occurs when the kidney cells start to grow in an uncontrolled and uncoordinated manner. These cancers can originate from the cells lining the tubules (carcinoma) or cells lining the blood vessels, fat, nerves, and muscles (sarcoma). Amongst them, renal cell carcinoma is the most common type of kidney cancer in adults accounting for 85 % of all kidney cancers.
Fortunately, the majority of kidney cancers are caught during the initial stages. It is estimated that only 18 % of all patients diagnosed with renal cell carcinoma show signs of metastasis. But 50 % of them develop metastatic renal cell carcinoma within three years after the treatment. Stage 3 (some cases) and stage 4 renal carcinoma show local and distant metastasis.
How Does Metastatic Renal Carcinoma Spread?
As cancer grows, it spreads to the surrounding tissues and organs. The lymphatic vessels and blood act as a medium through which cancer cells reach various body organs. Most often, kidney cancer spreads to the lungs and bones. The liver, ovaries, testes, and brain can be involved less commonly.
What Causes Metastatic Renal Carcinoma?
Metastatic renal cancer is not attributed to any particular cause. However, several risk factors have been identified that increase the chances of developing cancer. These include:
1. Smoking: Increases the risk of developing renal cancer by two times.
2. Gender: Males are twice as likely to develop renal cancer than females.
3. Obesity: Hormonal changes linked to obesity increase the risk.
4. Overusing Painkillers: If over-the-counter (OTC) pain medications are used for a long time.
5. Long-Standing Kidney Disease: Having poorly functioning kidneys due to underlying conditions increases the risk.
6. Family History of Renal Cancer: Having an immediate family member with kidney cancer increases the chances.
7. Certain Diseases: Genetic conditions such as Von Hippel-Lindau syndrome (a hereditary condition that causes the growth of tumors and cysts in certain body parts).
What Are the Signs and Symptoms of Metastatic Renal Carcinoma?
Initially, there might not be any signs and symptoms. However, once cancer grows to a certain extent, patients begin to experience it.
A. The Common Signs and Symptoms Include:
1. Passing blood in the urine (hematuria).
2. Presence of a lumpy mass in the abdomen.
3. Abdominal pain that does not subside.
4. Unexplained weight loss.
5. Fatigue and loss of appetite.
6. Development of anemia.
7. Swelling in extremities (ankles or legs).
8. Persistent fever.
B. Symptoms if the Kidney Cancer Has Spread to the Lungs:
1. Blood while coughing.
2. Difficulty breathing and gasping for breath.
3. Pain and tightness in the chest.
C. Symptoms if the Kidney Cancer Has Spread to the Bones:
1. Pain in the bones.
2. Bone are brittle and prone to fracture.
3. Weakness.
4. Altered calcium levels in the body.
How Is Metastatic Renal Carcinoma Diagnosed?
A. Physical Examination and Medical History: The clinician examines the body to identify unusual signs. A thorough medical history is helpful to determine the risk factors like smoking, obesity, and other kidney diseases.
B. Imaging Techniques: These include an ultrasound scan, CT (computed tomography) scan, MRI (magnetic resonance imaging), and PET (positron emission tomography) to visualize cancer and other involved organs.
C. Biopsy: A sample of the suspected tissue is removed using a scalpel, needle, or punch tool and studied under a microscope to identify cancerous changes.
D. Blood Chemistry: It is helpful in identifying specific tumor markers, the chemicals that are elevated during cancerous growth.
E. Urine Analysis: Changes in the content of the urine, such as sugar, protein, white blood cells, and red blood cells, are analyzed.
F. Additional Tests to Identify Metastasis: Bone scans and chest X-rays are required to identify lung and bone metastasis.
What Is the Treatment for Metastatic Renal Carcinoma?
Treatment of metastatic renal carcinoma depends on the stage of cancer and patients' factors such as age, systemic conditions, etc. Recommended treatment options include:
A. Surgery: A part of the entire kidney is removed during the surgery if one kidney is involved. The person will need dialysis or a kidney transplant if both kidneys are involved. The surgery is called a nephrectomy; the types include:
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Simple nephrectomy.
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Radical nephrectomy.
Arterial embolization is a technique used to shrink the tumor by inserting a catheter into the blood vessel when surgery is not possible.
B. Radiation Therapy: It is an adjunctive treatment that utilizes high-energy radiation to destroy cancer cells. Radiation therapy is carried out either before or after the surgery. It relieves symptoms and improves the quality of life.
C. Chemotherapy: Use of certain drugs to kill cancer cells or stop them from dividing further. Chemotherapeutic agents interfere with the cell cycle and can be given orally or intravenously.
D. Immunotherapy: Immunotherapeutic agents are the drugs that boost or help the body’s immune system to fight against cancer cells. Some medications used in immunotherapy for the treatment of metastatic renal cancer include Interferon, Nivolumab, Pembrolizumab, Avelumab, etc.
What Is the Life Expectancy and Prognosis of Metastatic Renal Carcinoma?
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The five-year survival rate for stage 3 renal carcinoma is estimated to be 53 %. This means that 53 out of 100 patients diagnosed with stage 3 renal carcinoma survive for five years or more.
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The five-year survival rate for stage 4 renal carcinoma is estimated to be 8 %, implying that eight out of 100 patients diagnosed with stage 4 renal carcinoma survive for five years or more.
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The estimated recurrence rate of renal cell carcinoma is 20 to 40 % after nephrectomy.
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According to statistics, the prognosis of metastatic renal carcinoma even after the treatment is poor.
Conclusion:
Metastatic renal carcinoma is a term used to describe renal cancer cells spread to the surrounding and distant organs. 18 % of all patients diagnosed with renal cell carcinoma show signs of metastasis. Symptoms of metastasis depend on the organ involved. The diagnosis is established after clinical examination and tumor imaging. Surgery is the first line of treatment, followed by radiation therapy, chemotherapy, and immunotherapy. The five-year survival rate of stage 3 and stage 4 renal carcinoma is 53 % and 8 %, respectively. Even with advanced treatment modalities, the prognosis of metastatic renal carcinoma is poor.
