High-dose therapy with autologous stem cell rescue for pediatric sarcomas

The principal pediatric sarcomas are Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma. While the prognosis for these diseases is generally favorable, it is possible to identify groups of patients with each diagnosis whose prognosis remains unacceptably poor. Based on the chemotherapy sensitivity of these tumors, many investigators have suggested that consolidation with high dose chemotherapy with or without radiation therapy followed by stem cell rescue could improve the prognosis for these high risk patients. This review evaluates the results of high dose therapy with stem cell reconstitution used to consolidate treatment of high risk patients with sarcomas.

The majority of the trials which have been conducted to assess this hypothesis have treated relatively small numbers of patients. They do not use consistent definitions of high risk. They have used different regimens for cytoreduction. They have used a variety of sources for stem cells. In many series, the consolidation therapy is applied only to patients who have achieved a significant response to prior therapy and the results have then been compared to a cohort of patients with similar presenting features, not all of whom responded to initial therapy.

The published results do not demonstrate an unequivocal benefit for consolidation with high-dose therapy. Future trials of high-dose therapy must define rigorous eligibility criteria, must have an appropriate, preferably randomized, control group, and must be designed with sufficient power to evaluate the hypothesis.