The increasingly blurred line between induction, consolidation and maintenance in acute myeloid leukaemia

Since the early 1970s, the treatment of acute myeloid leukaemia (AML) has undergone a major transformation. Initially based on only two drugs, an anthracycline and cytosine arabinoside, the aim of therapy was to achieve a haematological response allowing patients to recover and go home. Back in those early days, cure was not a realistic expectation. Treatment was analogous to a heart attack; upon recovery and a short respite, recurrence and death inevitably followed. Over the subsequent decades, slow but remarkable progress was made such that a subgroup of young adults could become long-term survivors. This astonishing feat was achieved initially without the use of new drugs. Supportive care played a major role with the widespread availability of platelet transfusions and improved antimicrobial therapy, particularly antifungal. No less important was the better use of existing drugs and the development of allogeneic haematopoietic cell transplantation. While initially the focus was on maximal tolerated therapy, an understanding of the immunologic role of allogeneic transplantation, better genetic characterization of the biology of the disease, advanced tools for detection of minimal disease as well as the recent development of new drugs changed the focus to a more refined approach targeting patients who are more likely to respond. Clearly, the historical paradigm where the term AML was generic and applicable to all patients requires a rethinking from the traditional therapeutic demarcations of therapy into phases of induction, consolidation and maintenance. These evolving new concepts and paradigm will be herein considered.