Treatment of Newly Diagnosed Childhood Soft Tissue Sarcoma
This entity accounts for 2% to 6% of all childhood STSs. These tumors can arise in previously irradiated sites or as a second malignancy in patients with retinoblastoma.
These tumors occur mainly in the second decade of life. In a series of ten patients, the median age was 10 years and the tumor was most commonly located in the extremities. In this series, all tumors were localized and five of nine (for whom follow-up was available) were alive in first remission. In another series of 17 pediatric patients with malignant fibrous histiocytoma, the median age at diagnosis was 5 years and the extremities were involved in eight cases. All patients with metastatic disease died and two patients experienced a clinical response to a doxorubicin-based regimen.
Tumors of Peripheral Nerves
Malignant peripheral nerve sheath tumor
Malignant peripheral nerve sheath tumor arises in children with type 1 neurofibromatosis (NF1), and it arises sporadically.
Features with favorable prognosis include the following:[65,66,67,68]
- Smaller tumor size—In a multivariate analysis, only tumor size and nuclear p53 expression were found to be independent predictors of disease-specific survival.
- Localized disease; no metastasis at presentation—A retrospective review of 140 patients with malignant peripheral nerve sheath tumor from the MD Anderson Cancer Center included children and adolescents. The disease-specific survival at 10 years was 32%. In this series, presence of metastatic disease was associated with a much worse prognosis. For patients with localized disease, there was no significant difference in outcome between patients with and without NF1.
- Lower stage.
- Lower histologic grade.
- Extremity as the primary site.
It is not clear whether the absence of NF1 is a favorable prognostic factor as it has been associated with both favorable  and unfavorable outcomes.[65,66,68]
There is agreement that complete surgical removal of the tumor, whenever possible, is the mainstay of treatment. The role of radiation therapy is difficult to assess, but durable local control of known postsurgical microscopic residual tumor is not assured after radiation therapy. Chemotherapy has achieved objective responses in childhood malignant peripheral nerve sheath tumor. A large retrospective analysis of the German and Italian experience with malignant peripheral nerve sheath tumor reported that 65% of measurable tumors had objective responses to ifosfamide-containing chemotherapy regimens, but the analysis did not conclusively demonstrate improved survival for chemotherapy. This retrospective analysis also noted a trend toward improved outcome with adjuvant radiation therapy. A series of 37 young patients with malignant peripheral nerve sheath tumor and NF1 showed that most patients had large invasive tumors that were poorly responsive to chemotherapy; progression-free survival was 19% and 5-year OS was 28%. The role of adjuvant chemotherapy following resection of malignant peripheral nerve sheath tumor has not been prospectively evaluated.