The role of intensive chemotherapy in myelodysplastic syndromes

Re-evaluation of refractory anemia with excess blasts in transformation

The category 'refractory anemia with excess blasts in transformation (RAEBt)' consists of two sub-sets; one group is categorized based on the percentage of blasts in the marrow (> or =20%) and other is based on the percentage of blasts in the peripheral blood (> or =5%). We separated RAEBt patients based on these two criteria and compared hematologic and clinical relevance to assess the reasonable basis for the new classification. All RAEBt patients showing peripheral blood (PB) blasts of > or =5% were re-classified as RAEB by the WHO classification. This subset of RAEBt patients had lower percentages of bone marrow (BM) blasts, and notably they showed frequent complex cytogenetic abnormalities, including -5/5q- and/or -7/7q-. Moreover, the RAEBt patients of this group had shorter survivals compared to RAEBt patients with BM blasts between 20 and 30%. We next assessed hematologic and clinical relevance between refractory anemia with excess blasts (RAEB) and RAEBt patients with PB blasts of > or =5%. Except for the percentage of blasts in the PB (P=0.0037) and BM (P=0.0073), there was no significant difference in hematologic or clinical features between RAEB patients with BM blasts of > or =11% and RAEBt patients with PB blasts of > or =5%. When MDS patients with PB blasts of > or =5% (RAEBt by the FAB classification) were included as RAEB-II based on the "MDS 2000 classification', there was a high frequency of patients with complex chromosome changes, involving 5q and 7q, with significant poorer outcome compared to those with RAEB-I. Although it is still controversial whether MDS patients with BM blasts 20% or more should be considered as acute leukemia, the utilization of the 'MDS 2000 classification' might be useful to designate MDS patients diagnosed based on the percentage of blasts in the peripheral blood.

Anthracyclines in haematology: pharmacokinetics and clinical studies

The activity of anthracyclines in the treatment of a wide spectrum of haematological malignancies has long been established. Differences in the pharmacokinetic and pharmacodynamic properties of these drugs have resulted in the selection of individual compounds for particular indications while the recent reformulation of anthracyclines in liposomal preparations seems likely to significantly alter their range of activity and toxicity. The problems related to cumulative cardiotoxicity secondary to anthracycline exposure can be ameliorated by the use of dexrazoxane and a number of agents may prove to have a role in altering their cellular resistance to their cytotoxic actions.

Stem Cell Transplantation for Secondary Acute Myeloid Leukemia: Evaluation of Transplantation as Initial Therapy or Following Induction Chemotherapy

The purpose of this report is to describe the results of stem cell transplantation as initial treatment for secondary acute myeloid leukemia (AML). Forty-six patients (median age 42 years) with secondary AML (17 therapy-related, 29 myelodysplasia-related) who had not received remission induction chemotherapy underwent allogeneic (n = 43) or syngeneic (n = 3) transplantation. The 5-year actuarial disease-free survival was 24.4%, and the cumulative incidences of relapse and nonrelapse mortality were 31.3% and 44.3%, respectively. Lower peripheral blood blast count was associated with a lower risk of relapse (P = .05) and shorter time from AML diagnosis to transplant was associated with a lower risk of nonrelapse mortality (P = .02) and improved disease-free survival (P = .026). Patients with therapy-related secondary AML tended to have lower disease-free survival (P = .16) and a higher relapse rate (P = .16) than patients whose leukemia was not therapy-related. The results of these 46 previously untreated patients were compared to 20 patients (median age 36 years, 12 therapy-related, 8 myelodysplasia-related) transplanted with chemotherapy-sensitive disease after induction chemotherapy (first complete remission [n = 6], second complete remission [n = 3], first untreated relapse [n = 11]). We found no statistically significant difference in outcome between these 2 groups of patients. These results suggest that prompt transplantation should be considered after diagnosis of secondary AML or, if possible, high-risk myelodysplasia, particularly in patients with low peripheral blast counts. Innovative transplant strategies are needed to reduce the high risks of relapse and nonrelapse mortality seen in this patient population.

Intensive chemotherapy of poor prognosis myelodysplastic syndromes (MDS) and acute myeloid leukemia following MDS with idarubicin and cytarabine

Forty patients with high risk myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) preceded by MDS were treated with intensive induction and consolidation chemotherapy in a prospective multicenter pilot study. They were given two cycles of cytarabine 100 mg/m with 12-h intervals on days 1-7 and idarubicin 12 mg/m2 on days 5-7, both intravenously. Patients who were in remission after these two cycles were given two further cycles of cytarabine on days 1-5 and idarubicin on day 5. No maintenance treatment was given. Eleven out of 19 MDS patients (58%) and 10 out of 21 AML patients (48%), in total 21 out of 40 patients (53%), entered remission. Eight patients underwent allogeneic bone marrow transplantation. The follow-up time was 13-48 (median 33) months. At the time of the analysis, seven patients survived, four patients with MDS all of whom had been treated with bone marrow transplantation (three in continuous remission), and three patients with AML treated with chemotherapy only (two in continuous remission). The median survival of the patients treated with chemotherapy only was 12 months, with the median progression-free survival being 8 months. In view of the poor prognostic factors of the patients, the remission rate was satisfactory, but the responses as well as the survival were short. The post-remission treatment needs to be improved.

Treatment and prognostic factors in myelodysplastic syndromes

While MDS remains an enigmatic disease, substantial progress has been made in the elucidation of its origin and the better understanding of its natural course. The advent of newer molecular and cytogenetic techniques has tremendously improved the 'older' morphological and histopathological prognostic criteria. More refined scoring systems may ultimately allow for individualized treatment programmes which will better preserve quality of life, while at the same time offer improved chances for survival and cure. Much can be expected from newer cytokines, such as thrombopoietin, stem cell factor, interleukin-11 or of the combination of different cytokines and growth factors, to alleviate MDS-symptoms and to possibly alter the course of the disease. After the initial disappointment with differentiation inducers, the availability of newer agents and/of combinations may offer better perspectives for the future. Much interest will also be generated on the use of mdr-reversal agents in the attempts to improve on chemotherapeutic efficacy. Finally, while allogeneic transplantation still remains the only option for definite cure of the disease, the spectacular advances made in the use and manipulation of autologous peripheral blood haemopoietic stem cells probably constitute the best hope for brightening the grim outlook most MDS patients still have.

Is aggressive chemotherapy the best choice for patients with acute nonlymphocytic leukemia after myelodysplastic syndromes?

Myelodysplastic syndromes (MDS) evolve in overt acute nonlymphocytic leukemia (ANLL) in about 40% of patients: the treatment of ANLL-MDS is not yet well clarified. To identify the role for aggressive and conservative approaches in ANLL-MDS, we evaluated retrospectively 78 patients in a 7-year period. Thirty-one patients (16 males and 15 females, median age 57.5 years, median MDS duration 5.5 months) were eligible for aggressive chemotherapy; 17 patients (54.8%) achieved complete remission (CR), 10 (32.3%) were resistant and 4 (12.9%) died during induction from infective complications. All patients that achieved CR relapsed, with a median CR duration of 6 months (range 2-28 months); median survival of the whole group was 8.5 months, while median survival of responders was 9 months. No prognostic factor revealed a statistical significance in the outcome, due to the small number of patients in each subgroup. Forty-seven patients (27 male and 20 female, median age 71.8 years, median MDS duration 10.1 months) were not eligible for aggressive chemotherapy; 16 patients (34.2%) received supportive care only, 31 patients (65.8%) needed conservative chemotherapy for disease progression. Median survival of the conservatively treated group was 5.5 months, without statistical difference from the aggressively treated group; 10/47 conservatively treated patients (21%) survived for longer than 12 months. In conclusion, aggressive chemotherapy may play a role only in a selected population of ANLL-MDS patients, while further studies could be helpful to identify the optimal conservative approach.