Wilms Tumor: Causes, Symptoms, Diagnosis, and Treatment

What is Wilms Tumor?

Wilms tumor is a rare type of kidney cancer that primarily affects children. Also called nephroblastoma, it is the most common pediatric kidney cancer. It is usually diagnosed in children between the ages of 3 and 4 and becomes much less common after age 5. However, in rare cases, it can occur in older children and even adults.

Wilms tumor usually develops in only one kidney, but in some cases, it can affect both kidneys at the same time.

Over the years, advances in early diagnosis and treatment have significantly improved outcomes. Today, with appropriate treatment, the prognosis for most children with Wilms tumor is very good.

Signs and Symptoms of Wilms Tumor

Wilms tumor may not always cause symptoms in its early stages. However, as the tumor grows, the following signs and symptoms can appear:

• Swelling or a noticeable mass in the abdomen, often on one side
• Abdominal pain or discomfort
• Fever without a clear cause
• Constipation
• High blood pressure (hypertension)
• Prominent or enlarged veins visible across the abdomen
• Blood in the urine (hematuria)
• Fatigue or unusual tiredness
• Loss of appetite
• Unexplained weight loss
• Recurrent or frequent urinary tract infections

If a child develops any of these symptoms, especially abdominal swelling, medical evaluation is important for proper diagnosis and timely treatment.

What Causes Wilms Tumor

Cancer develops when cells undergo changes (mutations) in their DNA. DNA contains the instructions that control how cells grow, divide, and function. When these instructions are altered, cells may begin to grow and multiply uncontrollably. Unlike normal cells, which follow a natural life cycle and eventually die, cancer cells continue to survive and accumulate. In Wilms tumor, these abnormal cells build up in the kidney and form a mass or tumor.

In rare cases, inherited genetic changes passed from parents to their children may increase the risk of developing Wilms tumor.

Risk Factors for Wilms Tumor

Several factors may increase a child’s risk of developing Wilms tumor:

1. Race

In North America and Europe, Black children have a slightly higher risk of Wilms tumor compared with children of other racial backgrounds. Asian-American children appear to have a somewhat lower risk.

2. Family History

A family history of Wilms tumor can increase the likelihood of developing the condition. Although most cases occur without a clear inherited cause, having a close relative with the disease raises the risk.

3. Certain Birth Conditions (Congenital Disorders)

Wilms tumor is more common in children born with specific physical or genetic conditions, such as:

• Aniridia
• Hemihypertrophy (Hemihyperplasia)

4. Rare Genetic Syndromes

Wilms tumor may also occur as part of certain rare genetic syndromes, such as:

• WAGR syndrome
• Denys-Drash syndrome
• Beckwith-Wiedemann syndrome

Although these risk factors can increase the likelihood of Wilms tumor, many children who develop the disease do not have any known risk factors.

Diagnosis of Wilms Tumor

Wilms tumor, a type of kidney cancer mainly affecting children, is diagnosed through clinical evaluation, imaging tests, and laboratory tests.

Clinical Evaluation

Doctors start with a physical exam to look for signs of Wilms tumor and may ask about the child’s family history.

Physical Exam: The doctor checks for possible signs of Wilms tumor, such as swelling or a noticeable mass in the abdomen.

Family History: They ask about the family history of kidney problems or cancers.

Imaging Tests

These imaging tests help doctors locate the tumor, determine its size, and see if it has spread.

Ultrasound: Often the first test to detect a kidney mass.

CT Scan (Computed Tomography): Provides detailed images of the tumor and surrounding organs.

MRI (Magnetic Resonance Imaging): Helps evaluate the size, spread, and involvement of blood vessels.

Chest X-ray or CT: Used to check if the cancer has spread to the lungs.

Laboratory Tests

These lab tests can indicate how well the kidneys are functioning.

Blood tests: To assess kidney function and overall health.

Urine tests: To check for blood or other abnormalities.

Treatment Options for Wilms Tumor

Treatment for Wilms tumor usually depends on the tumor size, stage, and whether it has spread, but the main options include:

Surgery

Treatment for Wilms tumor often starts with surgery to remove all or part of the affected kidney. Surgery also helps confirm the diagnosis, as the removed tissue is sent to a lab to check if it is cancerous and determine the tumor type.

Surgery may involve removing part of the kidney, called a partial nephrectomy, which is usually done for small tumors or when the child has only one working kidney. In a radical nephrectomy, the entire kidney is removed along with nearby lymph nodes, part of the ureter, and sometimes the adrenal gland. If both kidneys are affected, surgery removes as much cancer as possible from both kidneys. In such cases, the child may need dialysis or a kidney transplant.

Chemotherapy

Chemotherapy uses drugs to kill cancer cells. It can be given before surgery to shrink the tumor or after surgery to destroy any remaining cancer cells. This treatment helps reduce the risk of the cancer coming back.

Radiation Therapy

Radiation therapy uses high-energy rays to target and kill cancer cells. It is usually recommended for advanced stages or when the tumor has spread beyond the kidney.

Read more: Acute Kidney Failure: Causes, Symptoms, and Treatment

How Clinical Trials Are Shaping the Future of Cancer Treatment

Oncology clinical trials play a vital role in improving cancer treatment and patient outcomes. These research studies test potential new drugs, therapies, and treatment combinations to determine their safety and effectiveness. Through clinical trials, researchers aim to discover better ways to diagnose, treat, and even prevent different types of cancer. For example, renal cell carcinoma clinical trials are evaluating investigational therapies to determine if they can provide significant benefits beyond the current standard treatments for individuals living with RCC.

Conclusion:

In conclusion, Wilms tumor is a rare but highly treatable kidney cancer that mainly affects young children. Although the exact cause is often unknown, early detection plays a critical role in improving outcomes. Parents should pay close attention to unusual abdominal swelling or other persistent symptoms and seek medical advice promptly. Thanks to advances in diagnosis, surgery, chemotherapy, and radiation therapy, most children respond well to treatment and go on to live healthy lives. With timely care and proper medical support, the prognosis for Wilms tumor remains very encouraging for the majority of patients.