High-dose chemotherapy in soft tissue sarcoma in children.

Soft tissue sarcomas (STS) are highly malignant tumours that constitute 5-6% of all malignant childhood neoplasms. Of these, rhabdomyosarcoma (RMS) is the most common in children, and has a characteristic two-peak age incidence, 2-5 and 15-19 years. Most children with RMS are cured with conventional chemotherapy and local therapy (surgery with or without radiotherapy). Children with metastatic disease at presentation, particularly those older than 10 years or with bone marrow or bone involvement have a much poorer outcome. In this subgroup, high-dose therapy with stem cell rescue has been studied over the last two decades. Various single or multiagent chemotherapy regimens with or without radiotherapy and autologous stem cell rescue have been used as consolidation treatment with little success. Recent trials using sequential high-dose chemotherapy in the early phase of treatment have proved to be feasible, but the beneficial effect has to be confirmed. The role of purging remains unclear. Collaboration between different international groups is urgently required, in an attempt to improve the poor outcome of children with high risk STS.