Wilms Tumor

Definition:

• Wilms tumor (nephroblastoma) is a malignant renal tumor arising from primitive kidney (metanephric) blastemal cells.
• Most common primary kidney cancer in children.

Epidemiology

• Peak incidence: 2–5 years
• Slight female predominance
• Usually unilateral, but ~5–10% are bilateral
• Associated with syndromes: WAGR, Beckwith-Wiedemann, Denys-Drash

Clinical Features

• Abdominal mass (painless, palpable)
• Hematuria (sometimes)
• Abdominal pain, fever, hypertension
• Metastases: lungs most common

Diagnosis

• Imaging: Ultrasound, CT, or MRI of abdomen/pelvis
• Labs: Renal function, urinalysis, CBC
• Histology: blastemal, epithelial, stromal components
• Staging: NWTS/COG or SIOP protocols

Treatment & Pharmacist Role

1. Surgery

• Radical nephrectomy (unilateral)
• Nephron-sparing surgery for bilateral disease

2. Chemotherapy

• Standard-risk (unilateral, favorable histology):
  • Vincristine + Actinomycin D
• High-risk / advanced / anaplastic histology:
  • Add Doxorubicin

3. Radiotherapy

• For stage III / residual disease / pulmonary metastases

4. Pharmacist Considerations

• Vincristine: neuropathy, constipation, dose-limit 2 mg/dose
• Actinomycin D: myelosuppression, hepatotoxicity
• Doxorubicin: cardiotoxicity, cumulative dose monitoring
• Supportive care: antiemetics, hydration, growth factor support if needed
• Pediatric dosing: weight- or BSA-based

High-Yield Pharmacist Pearls

• Tumor rupture before/during surgery increases stage → may require RT and intensified chemo
• Hypertension may occur due to tumor mass
• Follow-up: monitor renal function (esp. if contralateral kidney involved), cardiac function (if Doxorubicin used), and growth