Adult Acute Lymphoblastic Leukemia: A Cancer with No Standard of Care

atrics. It has a 2-phase induction. The first phase includes 4 drugs (daunorubicin, prednisone, vincristine and asparaginase), and the second phase contains cyclophosphamide, cytarabine and 6-mercaptopurine. The drugs in the postremission cycles vary within each regimen and between regimens but include asparaginase and a late cycle of delayed reinduction (a truncated modified induction). Hoelzer et al. [4] adopted the BFM model and modified it for adults, and several of the subsequent adult regimens are variants of this model. The second model, the hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone (hyper-CVAD) regimen, was developed at the MD Anderson Cancer Center. It consists of 2 cycles alternating 4 times for a total of 8 cycles. Cycle A contains fractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone, mostly given in the first 5 days; cycle B contains high-dose methotrexate and high-dose cytarabine given over 3 days. In contrast to BFM-based regimens, it contains no asparaginase and is used almost only in adults [5] . The structure of 2 alternating cycles is simpler to follow, and it is widely used in the USA. No apparent outcome advantage was reported for either regimen, and the choice of any ALL treatment is generally based on prior training and practice preferences. The role of hematopoietic stem cell transplantation Approximately 6,000 new cases of acute lymphocytic leukemia (ALL) are diagnosed in the USA each year. Most occur in children, but 40% are in adults 20 years or older. In children, outcomes have improved due to sequential, well-conducted, multi-institutional, randomized clinical trials, rationally designed in a step-by-step manner. Consequently, approximately 80% of all children with ALL are cured. In contrast, the cure rate of adult ALL has remained at 35–40% over the past 30 years [1] . Many large multi-institutional studies were also conducted in adults, but most were not developed systematically and very few were randomized. Furthermore, despite variability in patient characteristics between regimens, the outcomes were almost identical. As a result, this rare cancer has no real ‘standard-of-care’ in adults [2] . In this issue of Acta Haematologica, Buyukasik et al. [3] report a retrospective comparison of 2 treatment approaches in adults. In general, the treatment of ALL is complex, with a variety of chemotherapy agents used in multiple cycles; all regimens include maintenance and central nervous system prophylaxis which distinguish the treatment of ALL from that of acute myeloid leukemia. With a few exceptions, most regimens can be grouped into 2 fundamentally different models [2] . The first of these, the BerlinFrankfurt-Munster (BFM) model, was developed in pediReceived: April 18, 2013 Accepted: April 22, 2013 Published online: June 19, 2013