Tumor Contamination of Stem Cell Products

Despite the success of the use of combination chemotherapy for the treatment of advanced-stage malignancies, the majority of these patients die of their disease. In an attempt to overcome drug resistance, there has been increasing use of high-dose therapy (HDT) with a curative attempt both in patients with previously relapsed disease and increasingly as consolidation therapy in first complete remission. The myeloablation induced by HDT can be reversed by autologous or allogeneic hematopoietic cell transplantation (autoHCT and alloHCT, respectively). Autologous cells have several potential advantages over allogeneic cells for HCT. Autologous HCT overcomes the need for an human leukocyte antigen (HLA)-identical donor, eliminates the risk of graft-vs-host-disease (GVHD) and has, therefore, enabled the use of chemotherapy dose escalation for a large number of patients with hematologic and solid tumors (1–4).