Hematopoietic Cell Transplantation for Other Pediatric Solid Tumors

The prognosis for recurrent or refractory pediatric solid tumors such as neuroblastoma, Wilms tumor, rhabdomyosarcoma, retinoblastoma, germ cell tumor, osteosarcoma, and Ewing sarcoma is dismal, and few patients have experienced prolonged survival. Most pediatric solid tumor patients are treated with intensive chemotherapy, and most recurrences occur during treatment or within 1 year of its completion. For agents such as melphalan, carmustine, and carboplatin, whose major dose limiting toxicity is myelosuppression, hematopoietic cell transplantation (HCT) may permit 3-10-fold dose escalation. The recognition that patients with bilateral retinoblastoma are at increased risk of developing osteosarcoma implicates the RB1 gene in the pathogenesis of osteosarcoma. The role of allogeneic HCT in pediatric solid tumors is being explored. Allogeneic transplantation carries the risk of graft-versus-host disease (GVHD), but its potential benefits include the absence of tumor cells in the graft and perhaps an immunologic antitumor effect.