High-Dose Therapy With Stem Cell Rescue for Ewing Sarcoma
For patients with a high risk of relapse with conventional treatments, certain investigators have utilized high-dose chemotherapy with hematopoietic stem cell transplant (HSCT) as consolidation treatment, in an effort to improve outcome.[23,24,25,26,27,28,29,30,31,32] In a prospective study, patients with bone and/or bone marrow metastases at diagnosis were treated with aggressive chemotherapy, surgery, and/or radiation and HSCT if a good initial response was achieved. The study showed no benefit for HSCT compared with historical controls. A retrospective review using international bone marrow transplant registries compared outcome after treatment with reduced-intensity conditioning to high-intensity conditioning followed by allogeneic stem cell transplant for patients with Ewing sarcoma at high risk for relapse.[Level of evidence: 3iiiA] There was no difference in outcome and the authors concluded that this suggested the absence of a clinically relevant graft-versus-tumor effect against Ewing sarcoma tumor cells with current approaches. Multiple small studies that report benefit for HSCT have been published but are difficult to interpret because only patients who have a good initial response to standard chemotherapy are considered for HSCT. The role of high-dose therapy followed by stem cell rescue is being investigated in a Euro-Ewing clinical trial (EURO-EWING-INTERGROUP-EE99) for patients that present with pulmonary metastases.
Ewing Sarcoma/Specific Sites
Separate journal articles have been written that discuss diagnostic findings, treatment, and outcome of patients with bone lesions at the following sites:
- Hand and foot.[41,42]
- Chest wall/rib.[43,44,45,46]
- Head and neck.
Extraosseous Ewing Sarcoma
Extraosseous Ewing sarcoma is biologically similar to Ewing sarcoma arising in bone. Until recently, most children and young adults with extraosseous Ewing sarcoma were treated on protocols designed for the treatment of rhabdomyosarcoma. This is important because many of the treatment regimens for rhabdomyosarcoma do not include an anthracycline, which is a critical component of current treatment regimens for Ewing sarcoma. Currently, patients with extraosseous Ewing sarcoma are eligible for studies that include Ewing sarcoma of bone.
From 1987 to 2004, 111 patients with nonmetastatic extraosseous Ewing sarcoma were enrolled on the RMS-88 and RMS-96 protocols. Patients with initial complete tumor resection received ifosfamide, vincristine, and actinomycin (IVA) while patients with residual tumor received IVA plus doxorubicin (VAIA) or IVA plus carboplatin, epirubicin, and etoposide (CEVAIE). Seventy-six percent of patients received radiation. The 5-year EFS and OS were 59% and 69%, respectively. In a multivariate analysis, independent adverse prognostic factors included axial primary, tumor size greater than 10 cm, Intergroup Rhabdomyosarcoma Studies Group III, and lack of radiation therapy.