Treatment of rhabdomyosarcoma is currently based on a staging system that incorporates both the primary site and histologic picture. The staging system also involves a local tumor group assessment based on the extent of disease and surgical result. In the intergroup rhabdomyosarcoma studies, the most common chemotherapy agents used are cyclophosphamide, vincristine, and actinomycin. Doxorubicin, etoposide, ifosfamide, topotecan, and irinotecan are also active against rhabdomyosarcoma. Radiation is administered to patients who have residual disease after initial surgery or who have only had a primary biopsy of the tumor.
The current treatment of osteosarcoma involves neoadjuvant chemotherapy followed by surgery and adjuvant chemotherapy. Agents effective against osteosarcoma are doxorubicin, cisplatin, high-dose methotrexate, ifosfamide, and etoposide. The treatment for Ewing sarcoma is similar to that for osteosarcoma; preoperative chemotherapy is given, followed by local control measures, and then further chemotherapy. In contrast to osteosarcoma, Ewing sarcoma is radiation sensitive. Chemotherapy includes vincristine, cyclophosphamide, ifosfamide, etoposide, and doxorubicin.
In addition to the risk of late effects from the chemotherapy, children with sarcomas have potential complications related to local control of the tumor. If the local disease is controlled with surgery, the long-term sequelae may include loss of limb or limitation of function. If local control is accomplished with radiation therapy, the late effects depend on the dose of radiation given, the extent of the site radiated, and the development of the child at the time of radiation therapy. Irradiating tissues interfere with growth and development, so significant adverse consequences may occur in young children.
For all children with sarcoma, presence or absence of metastatic disease at presentation is the most important prognostic factor. The outlook remains poor for patients who have distant metastasis from Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma at diagnosis. Patients with localized rhabdomyosarcomas in favorable sites have an excellent prognosis when treated with surgery followed by vincristine and actinomycin. In patients with osteosarcoma and Ewing sarcoma, another important prognostic factor is the degree of tumor necrosis after preoperative chemotherapy. In general, patients whose tumor specimens show a high degree (>90%) of necrosis following preoperative chemotherapy have an event-free survival rate greater than 80%. Patients who still have large amounts of viable tumor after presurgical chemotherapy have a much worse prognosis. The cure rate for patients with localized osteosarcoma and Ewing sarcoma is approximately 60% to 70%. Patients who have lung metastasis at diagnosis have a cure rate of approximately 30% to 35%. Patients with metastases to other bones have a poor prognosis.
Arndt CA, Rose PS, Folpe AL, et al: Common musculoskeletal tumors of childhood and adolescence, Mayo Clin Proc 87:475–487, 2012
Davenport KP, Blanco FC, Sandler AD: Pediatric malignancies: neuroblas toma, Wilms tumor, hepatoblastoma, rhabdomyosarcoma and sacrococ cygeal teratoma, Surg Clin North Am 92:745–767, 2012
Kopp LM, Gupta P, Pelayo-Katsanis L, et al.: Late effects in adult survivors of pediatric cancer: a guide for the primary care physician, Am J Med 125:636–641, 2012
Packer RJ, MacDonald T, Vezina G: Central nervous system tumors, Pediatr