What is the treatment approach for children diagnosed with rhabdomyosarcoma (RMS) in the kidney or liver?

Treatment Approach for Rhabdomyosarcoma in Kidney and Liver in Children

Children with rhabdomyosarcoma (RMS) in the kidney or liver require multimodal therapy including surgery, chemotherapy, and often radiation therapy delivered at specialized pediatric cancer centers with multidisciplinary expertise.

Diagnosis and Initial Evaluation

• Diagnosis requires adequate tissue biopsy for pathological, genetic, and biological characterization of the tumor
• Comprehensive staging workup including:
  • MRI/CT imaging of primary site
  • Evaluation for regional lymph node involvement
  • Metastatic workup (chest imaging, bone scan, bone marrow evaluation)
  • Molecular testing for specific genetic alterations

Treatment Strategy

Specialized Care Setting

• Treatment should be provided at pediatric cancer centers with extensive experience in treating RMS 1
• Multidisciplinary team must include pediatric oncologists, surgeons, radiation oncologists, pathologists, radiologists, and specialized support staff 1

Multimodal Treatment Approach

1. Surgery

   • Complete surgical resection when possible without causing major functional or cosmetic deficits 2
   • For visceral RMS (kidney/liver), initial biopsy followed by delayed resection after chemotherapy response is often preferred 2, 3

2. Chemotherapy

   • All patients with RMS require systemic chemotherapy 2
   • Standard backbone includes vincristine and dactinomycin with either:
     • Cyclophosphamide (VAC regimen)
     • Ifosfamide (IVA regimen) 2, 4
   • Duration typically 6-12 months depending on risk stratification

3. Radiation Therapy

   • Often indicated for incompletely resected tumors 2
   • Dose may be adjusted based on response to chemotherapy and surgical outcomes
   • Modern techniques aim to minimize exposure to normal tissues

Risk Stratification

Treatment intensity is determined by:

• Histologic subtype (embryonal vs. alveolar)
• Primary site (kidney/liver locations are generally unfavorable)
• Extent of disease (localized vs. metastatic)
• Surgical resection status
• Age (children <10 years typically have better outcomes) 2, 5

Clinical Trial Participation

• Enrollment in clinical trials should be strongly encouraged whenever possible 1
• Current trials focus on:
  • Risk-adapted therapy to reduce toxicity in favorable-risk patients
  • Novel agents (topotecan, irinotecan) for higher-risk disease 2, 4
  • Targeted therapies based on molecular characteristics

Outcomes and Prognosis

• 5-year survival rate >70% for localized RMS 2
• Poorer outcomes for metastatic disease at presentation
• Kidney/liver primary sites may have intermediate prognosis depending on other risk factors

Follow-up Care

• Regular surveillance imaging to monitor for recurrence
• Long-term monitoring for treatment-related toxicities:
  • Growth and development
  • Organ function (especially kidney/liver function)
  • Secondary malignancies
  • Fertility issues

Special Considerations

• Embryonal RMS (more common in young children) generally has better prognosis than alveolar subtype 5
• Genetic counseling should be considered as RMS may be associated with cancer predisposition syndromes 1
• Adolescent and young adult patients may benefit from specialized AYA oncology programs 1

The management of pediatric RMS has evolved significantly over the past decades, with current approaches focusing on risk-adapted therapy to maximize cure rates while minimizing long-term toxicities. Continued advances in molecular characterization and targeted therapies hold promise for further improving outcomes.