Standard Treatment for Wilms Tumor
The standard treatment for Wilms tumor consists of a multimodal approach including surgery (nephrectomy), chemotherapy with actinomycin D and vincristine, and radiation therapy for higher stages, with treatment intensity based on tumor stage and histology.
Diagnosis and Staging
- Initial evaluation should include:
- Abdominal ultrasound to detect renal masses
- CT or MRI to assess tumor extent and bilateral involvement
- Chest imaging to evaluate for metastases
- Genetic testing for associated syndromes (WT1, REST, CTR9, TRIM28)
Treatment Approach
Surgery
- Primary surgical approach:
- Radical nephrectomy is standard for unilateral tumors
- Nephron-sparing surgery (partial nephrectomy) for bilateral tumors or children with predisposition syndromes 1
- Lymph node sampling is essential for accurate staging
Chemotherapy
- FDA-approved regimens include:
- Actinomycin D at 45 mcg/kg IV once every 3-6 weeks for up to 26 weeks 2
- Often combined with vincristine as standard first-line therapy
- More intensive regimens (adding doxorubicin, cyclophosphamide, etoposide) for higher-stage or unfavorable histology
Radiation Therapy
- Indicated for:
- Stage III (local spread beyond kidney)
- Stage IV (metastatic disease)
- Unfavorable histology (anaplastic)
- Positive surgical margins
Treatment Algorithms by Stage
Stage I and II with Favorable Histology
- Nephrectomy with lymph node sampling
- Adjuvant chemotherapy with actinomycin D and vincristine for 18-24 weeks
Stage III with Favorable Histology
- Nephrectomy with lymph node sampling
- Adjuvant chemotherapy with actinomycin D and vincristine
- Addition of doxorubicin may be considered
- Radiation therapy to tumor bed
Stage IV with Favorable Histology
- Nephrectomy with lymph node sampling
- Intensified chemotherapy (actinomycin D, vincristine, doxorubicin)
- Radiation therapy to metastatic sites (typically lungs)
Unfavorable Histology (All Stages)
- More intensive chemotherapy regimens including cyclophosphamide and etoposide
- Higher radiation doses
Bilateral Wilms Tumor
- Initial biopsy followed by neoadjuvant chemotherapy
- Delayed nephron-sparing surgery when possible
- Adjuvant chemotherapy based on histology 3
Treatment Approach Differences
There are two major treatment approaches globally 4:
SIOP approach (Europe): Preoperative chemotherapy followed by surgery
- Advantages: Tumor shrinkage, reduced risk of tumor spillage
- Used for tumors >4cm
COG/NWTS approach (North America): Upfront surgery followed by chemotherapy
- Advantages: Accurate histological diagnosis before treatment
- Preferred for smaller tumors or when diagnosis is uncertain
Special Considerations
- Unresectable tumors: Initial chemotherapy to shrink tumor before surgical resection 5
- Bilateral disease: Nephron-sparing approaches are critical to preserve renal function 3
- Genetic predisposition: Children with genetic syndromes require surveillance for second tumors 1
- Relapsed disease: Intensified chemotherapy with agents not used in first-line treatment
Follow-up Care
- Regular abdominal imaging every 3-6 months for 2 years, then annually
- Chest imaging to monitor for pulmonary metastases
- Renal function monitoring, especially in bilateral cases
- Long-term surveillance for late effects of therapy (cardiac, renal, secondary malignancies)
The overall survival rate for Wilms tumor exceeds 90% for localized disease with favorable histology, making it one of the most successfully treated pediatric cancers when appropriate multimodal therapy is applied.