Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood. Fifteen percent of rhabdomyosarcoma patients already have metastases when the disease is discovered. With conventional dose chemotherapy survival generally is poor, therefore using 'high-dose' chemotherapy has been studied to see if this can improve survival. This type of chemotherapy has been shown to improve survival in metastatic neuroblastoma, another type of childhood cancer, when given after conventional chemotherapy with only very small amounts of neuroblastoma left. This might also be true for metastatic rhabdomyosarcoma. An alternative way of using high-dose chemotherapy is to use it 'up front', at the start of treatment; applied this way it could potentially kill tumour cells before resistance to chemotherapy develops.
Besides creating a possible benefit for patients, high-dose chemotherapy introduces significant extra risk of side effects above those of conventional chemotherapy. These include mucositis (severe inflammation of the mouth and gut) and bone marrow aplasia (when the body cannot make any blood elements and is at risk of life-threatening bleeding and infection). The administration of cells which can restore the bone marrow (haemopoietic stem cells) reduces this risk. These stem cells come from the patient themselves (autologous) or are donated from volunteers (allogenic). During the first weeks after high-dose chemotherapy, infections, bleeding and metabolic problems may occur, possibly counteracting the potential benefit of improved tumour control. In this review the authors analysed all relevant studies on the use of high-dose chemotherapy in metastatic rhabdomyosarcoma patients. The authors of this review found no evidence that supported the use of high-dose chemotherapy as a standard therapy for metastatic rhabdomyosarcoma.