Stem Cell Transplants in Acute Myeloid Leukaemia (AML)

The 10th United Kingdom Medical Research Council (MRC) AML trial showed a reduced overall relapse rate compared to previous trials, attributed largely to increased treatment intensity. Autologous bone marrow transplantation (ABMT) was also associated with a reduced rate of relapse. These benefits, however, were partly offset by slow neutrophil and platelet recovery after later courses of chemotherapy, and in the context of ABMT, the resulting high procedural mortality (12%) from infection and/or haemorrhage led to no overall survival benefit for ABMT. The 12th MRC AML trial aims to assess the benefit of further treatment intensification through randomisation to 4 or 5 chemotherapy courses for standard risk patients, and to examine further the role of ABMT. In an attempt to overcome some of the previous problems associated with delayed haemopoietic recovery, the trial incorporates the option to collect peripheral blood stem cells (PBSCs) and administer them as additional support after course 4, 5, or in association with ABMT, with the aim of facilitating more rapid haemopoietic reconstitution. Factors associated with optimal PBSC collections will be analysed as the trial proceeds. The theoretical risk of tumour contamination of PBSC samples will be assessed, where possible, by molecular techniques, and at close of trial in terms of relative relapse rate.