Secondary myelodysplasia and acute leukemia in breast cancer patients after autologous bone marrow transplant.

Purpose: To determine the incidence of myelodysplasia (MDS) and/or acute leukemia (AL) in breast cancer patients after high-dose chemotherapy (HDC) with a single conditioning regimen and autologous bone marrow transplant (ABMT), and analyze the cytogenetic abnormalities that arise after HDC.
Patients and Methods: We retrospectively reviewed the records of 864 breast cancer patients who underwent ABMT at Duke University Medical Center, Durham, NC, from 1985 through 1996 who received the same preparative regimen of cyclophosphamide 1,875 mg/m2 for 3 days, cisplatin 55 mg/m2 for 3 days, and BCNU 600 mg/m2 for 1 day (CPB). Pretransplant cytogenetics were analyzed in all patients and posttransplant cytogenetics were evaluated in four of five patients who developed MDS/AL.
Results: Five of 864 patients developed MDS/AL after HDC with CPB and ABMT. The crude cumulative incidence of MDS/AL was 0.58%. The Kaplan-Meier curve shows a 4-year probability of developing MDS/AL of 1.6%. Pretransplant cytogenetics performed on these five patients were all normal. Posttransplant cytogenetics were performed on four of five patients and they were abnormal in all four, although only one patient had the most common cytogenetic abnormality associated with secondary MDS/AL (chromosome 5 and/or 7 abnormality).
Conclusion: Whereas MDS/AL is a potential complication of HDC with CPB and ABMT, the incidence in this series of patients with breast cancer was relatively low compared with that reported in patients with non-Hodgkin's lymphoma who underwent ABMT. The cytogenetic abnormalities reported in this group of breast cancer patients were not typical of those seen in prior reports of secondary MDS/AL and appear to have occurred after HDC.