Nephroblastoma: Know All About It

Introduction:

Children under five are diagnosed with nephroblastoma (Wilms tumor). In 1899, Dr. Max Wilms, a German physician, characterized a tumor called Wilms tumor. It is the most frequently found kidney cancer in children. In addition, it is the fourth most common pediatric cancer and the most common pediatric abdominal cancer.

What Is the Etiology of Nephroblastoma?

• The exact etiology of nephroblastoma is unknown. However, genetic alterations in the genitourinary tract may play a role.

• WT1, CTNNB1, WTX, P53, and MYNC gene abnormalities are some genetic markers linked to the disease. TP53 has the worst prognosis.

• Another possible etiology of nephroblastoma could be due to nephrogenic resting cells.

• One percent of infantile kidneys may have them, but they usually regress in childhood.

• Only five percent of nephroblastoma tumor patients have bilateral disease, and girls are more likely to have it.

What Is the Epidemiology of Nephroblastoma?

• Nephroblastoma is the most typical childhood kidney cancer, often manifested between the ages of three and five.

• It is slightly more common in girls than in boys.

• In the United States, there are roughly 650 new cases each year.

• While East Asians are least likely to get nephroblastoma, it is more prone in Africans.

• Also, Asian patients had fewer tumors, poor histology, and lower-stage diseases with better survival rates.

• The rates in Europe and North America are comparable. With significant advancements in chemotherapy, most affected youngsters are still surviving.

What Are the Syndromes Associated With Nephroblastoma?

The WAGR syndrome-

• It is a unique syndrome connected to nephroblastoma: aniridia, genitourinary abnormalities, and mental retardation.

• The WT1 gene, which is involved in renal and gonad development, has a particular chromosomal defect in children with this syndrome, and there is a 50 percent chance for nephroblastoma development.

The Denys-Drash Syndrome-

• Often known as Drash syndrome, it is another syndrome connected to nephroblastoma.

• Pseudohermaphroditism in men and gradual renal failure that begins in infancy are examples of this.

What Are the Signs and Symptoms of Nephroblastoma?

The most frequent initial presenting symptom is abdominal discomfort (30 percent to 40 percent), followed by hypertension (25 percent) and hematuria (12 percent to 25 percent). The other characteristics are:

• An asymptomatic abdominal lump.

• Pain in the abdomen.

• Excessive hematuria.

• Infections of the urinary tract.

• Varicocele (enlargement of veins).

• High or low blood pressure (up to one-third of Wilms patients will show hypertension, which returns to normal after nephrectomy.)

• Fever.

• Anemia.

• Breathlessness in case of tumor spreads to the lungs.

How Is Neuroblastoma Diagnosed?

1. Blood Test: It involves the following tests:

• Regular blood tests are performed to check for signs of anemia.

• Complete blood count.

• Renal performance test.

• Urinalysis.

2. Genetic Testing: Cytogenetic testing to search for deletions of 1p and 16q.

3. Imaging: Planning a surgical procedure requires this imaging. Larger tumor sizes, contralateral extension, and displacement of the major vessels are surgical risk factors that frequently lead to more extended operating periods, blood loss, and complications. The following imaging tests are performed:

• Renal ultrasonography.

• X-ray of the chest to check for lung metastases.

• Computerized tomography (CT) of the chest and abdomen.

• Abdominal MRI (magnetic resonance imaging).

Chest imaging detects the spread of the tumor to the lungs. An abdominal CT scan and MRI also aid in diagnosing a nephroblastoma.

What Is the Treatment for Nephroblastoma?

• The primary treatment for nephroblastoma is nephrectomy and systemic chemotherapy.

• The doctors avoid a routine biopsy as it might elevate tumor staging to stage III unless there are exceptional conditions. This stage calls for radiation and chemotherapy.

• Postoperative radiation therapy may be utilized, depending on the histology and spread of the tumor.

• Initiating radiation therapy within 14 days of surgery for individuals without metastases increases overall survival.

• The more advanced disease typically requires combination chemotherapy.

• An urgent nephrectomy is avoided for children with bilateral illnesses.

• Some medical professionals try high-dose chemotherapy to eradicate the tumor cells and save the kidney.

• Since a bilateral nephrectomy necessitates dialysis immediately, every attempt must be made to save the kidneys.

• Patients with initial combination therapy relapse typically have a worse prognosis.

What Is the Differential Diagnosis for Nephroblastoma?

1. Clear Cell Renal Sarcoma: The prognosis of clear cell renal sarcoma is less favorable than nephroblastoma because the mortality and relapse rates are higher.

2. Congenital Mesoblastic Nephroma: It is often discovered on an ultrasound in the first year of life and is associated with hypertension and raised renin levels.

3. Renal Cell Carcinoma: It is a rare disease in children. However, when it does exist, it frequently has advanced beyond the stages of an adult. Patients with neuroblastoma who have completed radiation therapy and chemotherapy are more susceptible.

What Are the Complications Associated With Nephroblastoma?

Radiation and Chemotherapy:

• A person with higher-stage nephroblastoma treated with radiation and chemotherapy develops the risk of additional cancers in the following years.

• It is commonly known that radiation therapy raises the risk of thyroid, breast, bone, and colon cancers in later life.

Chemotherapy: Chemotherapy with Doxorubicin, Vincristine, and Dactinomycin raises the risk of subsequent cancers and toxicities such as hearing loss (Carboplatin), impaired heart function (Adriamycin), and peripheral neuropathy (Vincristine).

What Is Postoperative Care After Treatment?

The person must have the following monitored immediately following surgery:

1. The heart rate.

2. Temperature.

3. Blood sugar.

4. Electrolytes.

The follow-up appointments are often planned as follows:

1. Following a diagnosis.

2. Every three months for two years.

3. Every six months for another two years.

4. Once every two years.

The follow-up visits could consist of the following:

1. Checking for any signals of metastasis, thyroid growths, and abdominal exam for any evidence of any local recurrence or a liver tumor.

2. Assessment of the right-sided malignancies who underwent radiation therapy for liver/veno-occlusive disease.

Imaging testing will consist of the following:

1. Ultrasound.

2. Magnetic resonance imaging.

3. Chest X-ray.

4. Testing liver function.

5. Testing for renal blood function.

What Is the Prognosis of Nephroblastoma?

• The prognosis of this disease is affected by histology, and the tumor stage affects the prognosis of this disease.

• Depending on the stage, the survival rates range from 99 percent to 86 percent, whereas those for poor histology range from 84 percent to 38 percent.

• About one percent of individuals have end-stage renal failure.

• Women with the Wilms tumor-aniridia (WAGR) syndrome are more likely to get gonadoblastoma and may get streaked ovaries.

The following qualities are linked to a worse prognosis:

1. Older than two years of age.

2. Greater density of positive lymph nodes.

3. Enormous tumor size.

Conclusion:

Most children with neuroblastoma survive, particularly those with favorable histology detected early and treated adequately. However, practitioners must be cautious of infants who complain of stomach pain. An early referral to an oncologist is essential for increased survival as the diagnosis is typically distressing to the families.