All children with rhabdomyosarcoma require multimodality therapy with systemic chemotherapy, in conjunction with either surgery, radiation therapy (RT), or both modalities for local tumor control.[1-3] This treatment entails surgical resection, if feasible without major functional/cosmetic impairment, followed by chemotherapy. Some patients with initially unresected tumors may undergo second-look surgery to remove residual tumor. Because rhabdomyosarcoma is sensitive to chemotherapy and RT, surgery is delayed if it will result in disfigurement or if it will interfere with organ function. Chemotherapy and possibly RT are administered in advance with the hope that subsequent surgical resection will be successful without undesirable side effects. RT is indicated for patients with microscopic residual (Group II) disease and gross residual (Group III) disease. It is also recommended for Group I patients with alveolar histology. The discussion of treatment options for children with rhabdomyosarcoma is therefore divided into separate sections describing surgery, chemotherapy, and RT.

The treatment of rhabdomyosarcoma by the Children's Oncology Group and in Europe—as exemplified by trials from the Intergroup Rhabdomyosarcoma Study Group (IRSG), the Children's Oncology Group Soft Tissue Sarcoma Committee (COG-STS), and the International Society of Pediatric Oncology Malignant Mesenchymal Tumor (MMT)—differs in management and overall treatment philosopy.[2] In the MMT trials, a primary objective is to reduce the use of local therapy, relying on initial chemotherapy followed by alternate chemotherapy in the event of a poor response to initial therapy. Local therapy focused on surgical resection is then administered, reserving RT for use only after incomplete resection, documented regional lymph node involvement, or a poor clinical response to initial chemotherapy. This approach is designed to avoid major surgical procedures and especially RT, with their attendant morbidities. Overall survival (OS) is the primary end point, accepting the possibility of an inferior event-free survival (EFS) that might accompany nonaggressive local therapy when compared with more routine and earlier use of surgery and RT. The necessity of second-line salvage therapy for those who relapse is accepted in these trials. Conversely, the primary COG-STS objective has been to employ local therapy soon after initial chemotherapy, using RT for patients with residual disease after initial operation or biopsy only, and for patients with alveolar histology. EFS is the target end point, attempting to avoid relapse and salvage therapy. Results of these two approaches confirm that the IRSG trials resulted in superior EFS and better OS than the most recently published MMT 89 therapy. In some subsets of patients defined by primary site, the survival differences were greater (extremities, nonparameningeal head and neck); in others, the results were largely similar (genitourinary tract). Nevertheless, the overall impression is that survival for most patient subsets is superior with the use of early local therapy, including RT. However, in the MMT trials, some patients are spared aggressive local therapy, which may reduce the potential for morbidities associated with such therapy.[1-3]

References

1. Donaldson SS, Meza J, Breneman JC, et al.: Results from the IRS-IV randomized trial of hyperfractionated radiotherapy in children with rhabdomyosarcoma--a report from the IRSG. Int J Radiat Oncol Biol Phys 51 (3): 718-28, 2001.  [PUBMED Abstract]
   
   
2. Stevens MC, Rey A, Bouvet N, et al.: Treatment of nonmetastatic rhabdomyosarcoma in childhood and adolescence: third study of the International Society of Paediatric Oncology--SIOP Malignant Mesenchymal Tumor 89. J Clin Oncol 23 (12): 2618-28, 2005.  [PUBMED Abstract]
   
   
3. Donaldson SS, Anderson JR: Rhabdomyosarcoma: many similarities, a few philosophical differences. J Clin Oncol 23 (12): 2586-7, 2005.  [PUBMED Abstract]