¹Bone Marrow Transplantation, University Medical Center Hamburg, Martinistrasse, Hamburg, Germany. E-mail: nkroeger@uke.uni-hamburg.de

The analysis of autologous stem cell transplantation in patients with therapy-related myelodysplastic syndrome (t-MDS)/therapy-related acute myeloid leukemia (t-AML) was restricted to those patients who were reported to the European Group for Blood and Marrow Transplantation (EBMT) between 1991 and 2000. Therefore, the patients are highly selected by the physician who performed the transplant and no data are available about the reasons and about HLA donor availability. Registry studies can not replace prospective studies, but they are useful, because they represent the current practice. The relative low number of patients (n=65) registered in Europe over a 10-year time period and the high number of t-AML (n=55) in comparison to t-MDS (n=10) highlighted the selection bias. It is well-known that t-AML without preceded MDS are mainly induced by topoisomerase II targeted drugs and cytogenetic analysis showed a high frequency of rearrangements of chromosome band 11q23, t(8;21), t(15;17), inv (16) or t(8;16).¹ Patients with t-AML and favorable cytogenetic features have a significantly better survival than those with unfavorable cytogenetics.²

Therefore, this retrospective study is in line with other studies suggesting major impact of cytogenetic features in outcome of treatment related AML/MDS.