Current status of blood cell transplantation

Enhanced efficacy resulting from increased cytotoxic drug and/or radiation therapy dose intensity has been conclusively demonstrated for some cancer patients. For many cytotoxic agents, myelosuppression is a major dose limiting toxicity. Current established methods of rescue from myelo ablative therapy include allogenic bone marrow transplantation, autologous bone marrow transplantation, and peripheral blood cell transplantation. Optimal methods to obtain adequate stem cell yields have yet to be defined. The nature of intensity and duration of previous treatment seem to be more important in determining the success of mobilisation than the specific mobilisation strategy used. Tumour contamination is a major problem and effective purging techniques are urgently required. In vitro selection and expansion of CD34⁺ cells may be of value in those disorders in which tumour progenitors are CD34^-. Both positive stem cell selection and purging will probably be required for adequate purging. While maximising the dose intensity of effective agents is an important current strategy, the development of novel anti cancer strategies must continue to be our top priority.