Optimal Management Strategies for Rhabdomyosarcoma in Children

Abstract

Rhabdomyosarcoma is the most common sarcoma of childhood. Fortunately, the goal of cure is realistic for the majority of patients with localized tumors. However, management of these patients remains challenging. The fact that the tumor arises in a wide variety of primary sites, some of which are associated with specific patterns of local invasion, regional lymph node spread, and therapeutic response, requires physicians to be familiar with site-specific staging and treatment details. In addition, rhabdomyosarcoma requires multimodality therapy that can be associated with significant acute toxicities and long-term effects, particularly when administered to young children. These factors sometimes present a dilemma as to the best approach to optimize the chance of cure, minimize toxicity, and respect quality of life. The purpose of this review is to discuss 'optimal' management of this complicated tumor. Since the tumor is relatively rare, requires highly specialized care, and important management questions remain to be answered, optimal management of rhabdomyosarcoma includes enrollment in clinical trials whenever possible. Appropriate management begins with establishing the correct pathologic diagnosis, histologic subtype, primary site, extent of disease (International Society of Pediatric Oncology [SIOP]-TNM-Union Internationale Contre le Cancer stage or Intergroup Rhabdomyosarcoma Study Group [IRSG] stage), and extent of resection (IRSG group). Cooperative groups throughout North America and Europe have defined risk-adapted treatment based on these factors; this treatment requires a coordinated management plan that includes surgery, chemotherapy, and usually radiotherapy. The surgical approach for rhabdomyosarcoma is to excise the primary tumor whenever possible without causing major functional or cosmetic deficits. Wide excision is difficult in some primary sites and can be complicated by the fact that the tumor grows in a locally infiltrative manner so that complete resection is often neither possible nor medically indicated. Incompletely resected tumors are generally treated with radiotherapy. The cooperative groups reduce the dose of radiation based on the response of the tumor to chemotherapy and delayed primary resection to differing degrees. Response-adjusted radiation administration may reduce the long-term effects of radiotherapy, such as bone growth arrest, muscle atrophy, bladder dysfunction, and induction of second malignant neoplasms; however, it may also be associated with an increased risk of tumor recurrence. All patients with rhabdomyosarcoma require chemotherapy. A backbone of vincristine and dactinomycin with either cyclophosphamide (VAC) or ifosfamide (IVA) has been established. Risk-adapted treatment involves reducing or eliminating the alklyating agent for patients with the most favorable disease characteristics. Clinical trials are ongoing to improve outcomes for higher risk patients; newer agents, such as topotecan or irinotecan, in combination with VAC or use of agents in novel ways are ...

Management of pediatric head and neck rhabdomyosarcoma: A case-series of 36 patients

“…It was reported that, by undergoing complete surgical resection, these patients avoid radiotherapy and its long-term complications, with no compromise in survival (31). Patients in whom radical resection with healthy tissues margin is impossible should receive neoadjuvant chemotherapy (27,32). A postponed procedure must be performed upon achieving satisfactory response to chemotherapy (32).…”

“…Patients in whom radical resection with healthy tissues margin is impossible should receive neoadjuvant chemotherapy (27,32). A postponed procedure must be performed upon achieving satisfactory response to chemotherapy (32). Second-look surgery must be undertaken to resect viable tumors after the administration of definitive local therapy (1).…”

Prognostic factors in soft-tissue sarcomas: what have we learnt?

“…It is becoming more apparent that the response to chemotherapy may be stratified by the histologic type, and that successful chemotherapy regimes will require acknowledgement of this [40]. For example, rhabdomyosarcomas are relatively sensitive to conventional chemotherapy, especially the embryonal subtypes that occur in the pediatric age group [41,42]. Myxoid liposarcoma is another group that appears to be responsive to chemotherapy despite being low grade, while the dedifferentiated form of liposarcoma is not.…”

Outcome of 449 adult patients with rhabdomyosarcoma: an observational ambispective nationwide study

“…Five‐year overall survival (OS) of children has dramatically improved in the last 30 years based on the results of successive studies of large multinational collaborative trials dedicated to children. Currently, the 5‐year OS exceeds 70% for nonmetastatic RMS 5, 6, 7, 8, 9, 10. In contrast, the outcome of adult patients remains poor.…”