Incidence and characterization of secondary myelodysplastic syndromes following autologous transplantation

Secondary myelodysplastic syndromes (sMDS) and secondary acute myeloid leukemias (sAML) have been observed after conventional chemo/radiotherapy and autologous hematopoietic stem cell transplantation. The aim of the present study was to analyze Spanish experience regarding the incidence and characteristics of sMDS and sAML following autologous transplantation.

We obtained information from 7 institutions which perform autologous transplantation in Spain. Data from 1,081 and 1,411 patients who had received allogeneic and autologous transplantation, respectively, were available.

None of the allografted patients had developed a sMDS/sAML so far. Thirteen cases of sMDS/sAML following autologous transplantation were reported. The mean age of these 13 patients at the time of transplantation was 40 years (range 16-58). Five had non-Hodgkin's lymphoma, 6 had Hodgkin's disease, 1 had acute myeloblastic leukemia and 1 had multiple myeloma. The crude overall incidence of sMDS/sAML was 0.9%. The incidence did not differ according to the source of progenitor cells (1% and 0.8% for bone marrow and peripheral blood, respectively). Cytogenetic analysis showed clonal abnormalities in 11 of the 13 cases. Patients with sMDS/sAML had received more doses of alkylating agents than non-sMDS patients (p = 0.0015). The median time between transplantation and diagnosis of sMDS/sAML was 28 months (range 1.5-63). This time was significantly longer for patients who received bone marrow than for those who received peripheral blood (45 versus 18 months, p = 0.01). Median overall survival after diagnosis of sMDS/sAML was 13 months.

The crude incidence of sMDS/sAML in our series was similar to other published incidences. We did not find any difference in incidence between patients who had received bone marrow or peripheral blood; however, the medi an time elapsed between transplantation and sMDS diagnosis was shorter when peripheral blood was infused. Higher doses of alkylating agents were associated with the appearance of sMDS/AML.