Wilms Tumor

Wilms tumor, also called nephroblastoma, is a rare cancer that usually begins in one kidney in young children. It is one of the most common kidney cancers of childhood. Most cases are diagnosed in children younger than 5 years. Occasionally, Wilms tumor affects both kidneys.

Wilms tumor develops when immature kidney cells acquire genetic changes that allow them to grow and divide without normal control. These abnormal cells can form a mass in the kidney. For most children, the exact cause of these changes is unknown.

Sporadic and inherited forms

Some tumors are linked to changes in genes involved in kidney development or in particular chromosome regions. Many others occur sporadically, meaning there is no known inherited cause. Parents do not cause Wilms tumor through anything they did or did not do.

Possible complications of the tumor

Evaluation may include a physical examination, blood tests, urine tests, and abdominal ultrasound. CT or MRI can show the size and location of a kidney mass, while chest imaging checks whether disease may have spread to the lungs. Clinicians compare these findings with conditions such as neuroblastoma and other kidney masses before confirming the diagnosis and treatment plan.

How staging describes the tumor

Surgery

Surgery is one of the main treatments for Wilms tumor. The most common surgical procedure is a nephrectomy, in which the affected kidney and tumor are removed. Nearby lymph nodes may also be examined to determine whether the tumor has spread.

When both kidneys are affected, doctors may try to preserve as much healthy kidney tissue as possible. This approach, known as nephron-sparing surgery, may be considered in selected cases.

Chemotherapy

Chemotherapy uses medicines to destroy cancer cells or prevent them from multiplying. It is commonly used as part of Wilms tumor treatment.

Depending on the tumor’s stage and biological characteristics, chemotherapy may be given before surgery to shrink the tumor or after surgery to eliminate remaining cancer cells. Common chemotherapy medicines used for Wilms tumor can include vincristine, dactinomycin, and doxorubicin. More intensive combinations may be used for tumors with higher-risk features.

Radiation Therapy

Radiation therapy uses high-energy radiation to destroy cancer cells. It is not required for every child with Wilms tumor.

Radiation may be recommended when the tumor has certain high-risk characteristics, when there is residual disease after surgery, or when the cancer has spread to areas such as the lungs or abdomen. Because children can be particularly sensitive to the long-term effects of radiation, doctors carefully consider its potential benefits and risks.

Treatment According to Tumor Stage

Treatment is generally tailored to the stage of the disease.

• Early-stage Wilms tumor: Surgery followed by chemotherapy is commonly used, although the exact treatment depends on the tumor’s histology and other risk factors.
• Intermediate-stage disease: Surgery and chemotherapy are typically combined, with radiation considered for selected patients.
• Advanced-stage disease: Treatment may involve more intensive chemotherapy, surgery, and radiation therapy depending on where the cancer has spread.
• Bilateral Wilms tumor: Treatment is designed to control the cancer while preserving kidney function whenever possible.

Treatment for Relapsed or Refractory Wilms Tumor

Sometimes Wilms tumor returns after initial treatment. This is called relapsed disease. Treatment options may include combinations of chemotherapy, surgery, radiation therapy, and, in selected cases, high-dose chemotherapy with stem cell support.

The treatment plan for recurrent disease depends on the treatments previously received, the location of the recurrence, and the tumor’s biological characteristics.

Follow-Up and Long-Term Care

Regular follow-up is an important part of Wilms tumor care. Doctors may use physical examinations, blood tests, imaging studies, and kidney-function tests to monitor for recurrence and assess long-term health.

Children who have been treated for Wilms tumor may also need long-term monitoring for potential effects of chemotherapy, radiation therapy, or loss of kidney tissue. Protecting kidney function and monitoring blood pressure are particularly important when one kidney remains.

A Multidisciplinary Approach

Wilms tumor treatment is usually managed by a specialized pediatric oncology team. Depending on the child’s needs, this team may include pediatric oncologists, pediatric surgeons, radiation oncologists, radiologists, pathologists, nurses, and other specialists.

Because Wilms tumor can vary significantly from one child to another, treatment should be individualized according to the specific diagnosis and risk group. Parents and caregivers should discuss the available options, expected benefits, possible side effects, and long-term follow-up plan with the child’s medical team.

Many children with Wilms tumor can be cured, but the outlook differs from child to child. Prognosis depends on the stage, tumor histology and biology, age, response to treatment, and whether one or both kidneys are involved. The risk of recurrence and the need for additional treatment also depend on these features.

Follow-up usually includes scheduled examinations and imaging to check for recurrence, along with blood pressure checks and kidney-function monitoring. The care team may also review growth, development, school progress, emotional health, and treatment-related late effects. Follow-up schedules vary according to the child’s treatment and risk group.