The role of intensive chemotherapy in myelodysplastic syndromes

We review results of intensive chemotherapy (IC) obtained in myelodysplastic syndromes (MDS). Overall, the complete remission (CR) rates and median CR duration obtained with IC are low in MDS, especially when compared to results obtained in de novo AML treated with the same chemotherapy regimens; very few MDS patients achieve prolonged remissions. Failure to achieve CR, in MDS, results both from a high incidence of resistant disease and toxic deaths, the latter being due to longer periods of aplasia than in de novo AML. However some subgroups of MDS seem to obtain higher CR rates and more prolonged remissions. These include patients younger than 45 to 50 years, those with a large excess of marrow blasts or Auer rods at diagnosis, and patients with a normal karyotype or at least without involvement of chromosomes 5 and/or 7. Results of IC clearly have to be improved in MDS. Higher CR rates may possibly be obtained by intensifying induction regimens, but this will probably require the addition of growth factors, in order to reduce the already very long periods of aplasia seen with IC in MDS. For consolidation therapy, new approaches, and especially autologous bone marrow transplantation, will have to be investigated.