High dose therapy and autologous bone marrow transplant (ABMT) in acute leukemia: is purging necessary?

Multiple clinical studies have been undertaken to evaluate the role of ABMT in relapse, in second and subsequent remission (CR greater than or equal to 2), and in first remission (CR1). The value of these high dose cytoreductive programs with ABMT is not yet known. No randomized studies have been done yet indicating that ABMT is superior to conventional dose chemotherapy. Besides, the diversity of regimens and patient populations make evaluation of results extremely difficult. When these variables are taken into account, the effect of purging on the clinical results becomes unclear. Multiple methods of purging have been devised, and several clinical trials have been reported. Although the biological role of purging is still unknown, theoretical considerations will be discussed and recommendations of patient subpopulations in which purging might be effective will be given.